data-es2016plus.js

var common = require('./data-common');

var babel = common.babel;
var typescript = common.typescript;
var firefox = common.firefox;
var chrome = common.chrome;
var edge = common.edge;
var graalvm = common.graalvm;

exports.name = 'ES2016+';
exports.target_file = 'es2016plus/index.html';
exports.skeleton_file = 'es2016plus/skeleton.html';

exports.tests = [
  {
    name: 'exponentiation (**) operator',
    category: '2016 features',
    significance: 'small',
    spec: 'http://www.ecma-international.org/ecma-262/7.0/index.html#sec-exp-operator',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators#Exponentiation_(**)',
    subtests: [
      {
        name: 'basic support',
        exec: function () {/*
          return 2 ** 3 === 8 && -(5 ** 2) === -25 && (-5) ** 2 === 25;
        */},
        res: {
          tr: true,
          babel6corejs2: true,
          closure: true,
          typescript1corejs2: true,
          ie11: false,
          edge13: edge.experimental,
          edge14: true,
          firefox2: false,
          firefox42: firefox.nightly,
          firefox52: true,
          opera10_50: false,
          chrome51: chrome.experimental,
          chrome52: true,
          safari10_1: true,
          duktape2_0: true,
          jerryscript2_3_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false,
          rhino1_7_14: true,
        }
      },
      {
        name: 'assignment',
        exec: function () {/*
          var a = 2; a **= 3; return a === 8;
        */},
        res: {
          tr: true,
          babel6corejs2: true,
          closure: true,
          typescript1corejs2: true,
          ie11: false,
          edge13: edge.experimental,
          edge14: true,
          firefox2: false,
          firefox48: firefox.nightly,
          firefox52: true,
          opera10_50: false,
          chrome51: chrome.experimental,
          chrome52: true,
          safari10_1: true,
          duktape2_0: true,
          jerryscript2_3_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false,
          rhino1_7_14: true,
        }
      },
      {
        name: 'early syntax error for unary negation without parens',
        exec: function () {/*
          if (2 ** 3 !== 8) { return false; }
          try {
            Function ("-5 ** 2")();
          } catch (e) {
            return true;
          }
        */},
        res: {
          babel6corejs2: true,
          closure: true,
          ie11: false,
          edge14: true,
          firefox2: false,
          firefox52: true,
          opera10_50: false,
          chrome51: chrome.experimental,
          chrome52: true,
          safari10_1: true,
          duktape2_0: false,
          jerryscript2_3_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false,
          rhino1_7_14: true,
        }
      }
    ]
  },
  {
    name: 'Object static methods',
    spec: 'https://tc39.github.io/ecma262/#sec-properties-of-the-object-constructor',
    category: '2017 features',
    significance: 'medium',
    subtests: [
      {
        name: 'Object.values',
        spec: 'https://tc39.github.io/ecma262/#sec-object.values',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/values',
        category: '2017 features',
        significance: 'medium',
        exec: function () {/*
          var obj = Object.create({ a: "qux", d: "qux" });
          obj.a = "foo";
          obj.b = "bar";
          obj.c = "baz";
          var v = Object.values(obj);
          return Array.isArray(v) && String(v) === "foo,bar,baz";
        */},
        res: {
          babel6corejs2: babel.corejs,
          closure: true,
          es7shim: true,
          typescript1corejs2: typescript.corejs,
          firefox2: false,
          firefox45: firefox.nightly,
          firefox47: true,
          opera10_50: false,
          chrome51: chrome.experimental,
          chrome54: true,
          ie11: false,
          edge14: true,
          safari10_1: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false,
          rhino1_7_14: true,
        }
      },
      {
        name: 'Object.entries',
        spec: 'https://tc39.github.io/ecma262/#sec-object.entries',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/entries',
        exec: function () {/*
          var obj = Object.create({ a: "qux", d: "qux" });
          obj.a = "foo";
          obj.b = "bar";
          obj.c = "baz";
          var e = Object.entries(obj);
          return Array.isArray(e)
            && e.length === 3
            && String(e[0]) === "a,foo"
            && String(e[1]) === "b,bar"
            && String(e[2]) === "c,baz";
        */},
        res: {
          babel6corejs2: babel.corejs,
          closure: true,
          es7shim: true,
          typescript1corejs2: typescript.corejs,
          firefox2: false,
          firefox45: firefox.nightly,
          firefox47: true,
          opera10_50: false,
          chrome51: chrome.experimental,
          chrome54: true,
          ie11: false,
          edge14: true,
          safari10_1: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false,
          rhino1_7_14: true,
        }
      },
      {
        name: 'Object.getOwnPropertyDescriptors',
        spec: 'https://tc39.github.io/ecma262/#sec-object.getownpropertydescriptors',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/getOwnPropertyDescriptors',
        exec: function () {/*
          var object = {a: 1};
          var B = typeof Symbol === 'function' ? Symbol('b') : 'b';
          object[B] = 2;
          var O = Object.defineProperty(object, 'c', {value: 3});
          var D = Object.getOwnPropertyDescriptors(O);

          return D.a.value === 1 && D.a.enumerable === true && D.a.configurable === true && D.a.writable === true
            && D[B].value === 2 && D[B].enumerable === true && D[B].configurable === true && D[B].writable === true
            && D.c.value === 3 && D.c.enumerable === false && D.c.configurable === false && D.c.writable === false;
        */},
        res: {
          babel6corejs2: babel.corejs,
          closure: true,
          es7shim: true,
          typescript1corejs2: typescript.corejs,
          ie11: false,
          edge15: true,
          chrome51: chrome.experimental,
          chrome54: true,
          firefox2: false,
          firefox50: true,
          opera10_50: false,
          safari10: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false,
          rhino1_7_15: true,
        }
      },
      {
        name: "Object.getOwnPropertyDescriptors doesn't provide undefined descriptors",
        exec: function () {/*
          var P = new Proxy({ a: 1 }, {
            getOwnPropertyDescriptor: function (t, k) {}
          });
          return !Object.getOwnPropertyDescriptors(P).hasOwnProperty('a');
        */},
        res: {
          babel6corejs2: babel.corejs,
          typescript1corejs2: typescript.corejs,
          ie11: false,
          edge15: true,
          firefox2: false,
          firefox50: true,
          opera10_50: false,
          chrome54: true,
          safari10_1: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      }
    ]
  },
  {
    name: 'Array.prototype.includes',
    spec: 'http://www.ecma-international.org/ecma-262/7.0/index.html#sec-array.prototype.includes',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/includes',
    category: '2016 features',
    significance: 'small',
    subtests: [
      {
        name: 'Array.prototype.includes',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/includes',
        exec: function () {/*
          return [1, 2, 3].includes(1)
            && ![1, 2, 3].includes(4)
            && ![1, 2, 3].includes(1, 1)
            && [NaN].includes(NaN);
        */},
        res: {
          babel6corejs2: babel.corejs,
          closure: true,
          es7shim: true,
          typescript1corejs2: typescript.corejs,
          safari9: true,
          chrome47: true,
          ie11: false,
          edge14: true,
          firefox2: false,
          firefox43: true,
          opera10_50: false,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: true
        }
      },
      {
        name: 'Array.prototype.includes handles sparse arrays',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/includes',
        exec: function () {/*
          return [,].includes()
            && Array(1).includes();
        */},
        res: {
          babel6corejs2: babel.corejs,
          closure: true,
          es7shim: true,
          typescript1corejs2: typescript.corejs,
          safari9: true,
          chrome47: true,
          ie11: false,
          edge14: true,
          firefox2: false,
          firefox43: true,
          firefox99: false,
          firefox102: true,
          opera10_50: false,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: true
        }
      },
      {
        name: 'Array.prototype.includes is generic',
        exec: function () {/*
          var passed = 0;
          return [].includes.call(
            {
              get "0"() {
                passed = NaN;
                return 'foo';
              },
              get "11"() {
                passed += 1;
                return 0;
              },
              get "19"() {
                passed += 1;
                return 'foo';
              },
              get "21"() {
                passed = NaN;
                return 'foo';
              },
              get length() {
                passed += 1;
                return 24;
              }
            },
            'foo',
            6
          ) === true && passed === 3;
        */},
        res: {
          babel6corejs2: babel.corejs,
          closure: false,
          closure20180402: true,
          es7shim: true,
          typescript1corejs2: typescript.corejs,
          safari9: true,
          chrome47: true,
          ie11: false,
          edge14: true,
          firefox2: false,
          firefox43: true,
          opera10_50: false,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false,
          rhino1_7_14: true,
        }
      },
      {
        name: '%TypedArray%.prototype.includes',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray/includes',
        exec: function () {/*
          return [
            Int8Array,
            Uint8Array,
            Uint8ClampedArray,
            Int16Array,
            Uint16Array,
            Int32Array,
            Uint32Array,
            Float32Array,
            Float64Array
          ].every(function (TypedArray) {
            return new TypedArray([1, 2, 3]).includes(1)
            && !new TypedArray([1, 2, 3]).includes(4)
            && !new TypedArray([1, 2, 3]).includes(1, 1);
          });
         */},
        res: {
          babel6corejs2: babel.corejs,
          typescript1corejs2: typescript.corejs,
          chrome47: true,
          ie11: false,
          edge14: true,
          firefox2: false,
          firefox43: true,
          opera10_50: false,
          safari10: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      }
    ]
  },
  {
    name: 'String padding',
    category: '2017 features',
    significance: 'small',
    spec: 'https://github.com/tc39/proposal-string-pad-start-end',
    subtests: [
      {
        name: 'String.prototype.padStart',
        spec: 'https://tc39.github.io/ecma262/#sec-string.prototype.padstart',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/padStart',
        exec: function () {/*
          return 'hello'.padStart(10) === '     hello'
            && 'hello'.padStart(10, '1234') === '12341hello'
            && 'hello'.padStart() === 'hello'
            && 'hello'.padStart(6, '123') === '1hello'
            && 'hello'.padStart(3) === 'hello'
            && 'hello'.padStart(3, '123') === 'hello';
         */},
        res: {
          babel6corejs2: babel.corejs,
          closure: true,
          typescript1corejs2: typescript.corejs,
          es7shim: true,
          firefox2: false,
          firefox48: true,
          opera10_50: false,
          ie11: false,
          edge14: edge.experimental,
          edge15: true,
          chrome52: chrome.experimental,
          chrome57: true,
          node8: true,
          safari10: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: true
        }
      },
      {
        name: 'String.prototype.padEnd',
        spec: 'https://tc39.github.io/ecma262/#sec-string.prototype.padend',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/padEnd',
        exec: function () {/*
          return 'hello'.padEnd(10) === 'hello     '
            && 'hello'.padEnd(10, '1234') === 'hello12341'
            && 'hello'.padEnd() === 'hello'
            && 'hello'.padEnd(6, '123') === 'hello1'
            && 'hello'.padEnd(3) === 'hello'
            && 'hello'.padEnd(3, '123') === 'hello';
         */},
        res: {
          babel6corejs2: babel.corejs,
          closure: true,
          typescript1corejs2: typescript.corejs,
          es7shim: true,
          firefox2: false,
          firefox48: true,
          opera10_50: false,
          ie11: false,
          edge14: edge.experimental,
          edge15: true,
          chrome52: chrome.experimental,
          chrome57: true,
          node8: true,
          safari10: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: true
        }
      }
    ]
  },
  {
    name: 'trailing commas in function syntax',
    spec: 'https://github.com/tc39/proposal-trailing-function-commas',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Trailing_commas',
    category: '2017 features',
    significance: 'small',
    subtests: [
      {
        name: 'in parameter lists',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Trailing_commas#Parameter_definitions',
        exec: function () {/*
          return typeof function f( a, b, ) {} === 'function';
        */},
        res: {
          babel6corejs2: true,
          closure: true,
          typescript2corejs2: true,
          ie11: false,
          edge14: true,
          chrome57: chrome.experimental,
          chrome58: true,
          firefox2: false,
          firefox52: true,
          opera10_50: false,
          node8: true,
          safari10: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false,
          rhino1_7_15: true,
        }
      },
      {
        name: 'in argument lists',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Trailing_commas#Function_calls',
        exec: function () {/*
          return Math.min(1,2,3,) === 1;
        */},
        res: {
          babel6corejs2: true,
          closure: true,
          typescript2corejs2: true,
          ie11: false,
          edge14: true,
          chrome57: chrome.experimental,
          chrome58: true,
          firefox2: false,
          firefox52: true,
          opera10_50: false,
          node8: true,
          safari10: true,
          duktape2_0: false,
          jerryscript2_3_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: true
        }
      }
    ]
  },
  {
    name: 'async functions',
    category: '2017 features',
    significance: 'large',
    spec: 'https://tc39.github.io/ecma262/#sec-async-function-definitions',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/async_function',
    subtests: [
      {
        // Should test that async functions return promises
        // that (without await) resolve to the returned value.
        name: 'return',
        exec: function () {/*
          async function a() {
            return "foo";
          }
          var p = a();
          if (!(p instanceof Promise)) {
            return false;
          }
          p.then(function (result) {
            if (result === "foo") {
              asyncTestPassed();
            }
          });
        */},
        res: {
          tr: true,
          babel6corejs2: babel.regenerator,
          closure: true,
          typescript1corejs2: typescript.downlevelIteration,
          chrome52: chrome.experimental,
          chrome55: true,
          ie11: false,
          edge13: edge.experimental,
          edge15: true,
          firefox2: false,
          firefox52: true,
          opera10_50: false,
          safari10_1: true,
          duktape2_0: false,
          jerryscript2_3_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'throw',
        exec: function () {/*
          async function a() {
            throw "foo";
          }
          var p = a();
          if (!(p instanceof Promise)) {
            return false;
          }
          p.catch (function (result) {
            if (result === "foo") {
              asyncTestPassed();
            }
          });
        */},
        res: {
          tr: null,
          babel6corejs2: null,
          babel7corejs2: babel.regenerator,
          closure: true,
          typescript1corejs2: typescript.downlevelIteration,
          chrome52: null,
          chrome55: true,
          ie11: false,
          edge13: edge.experimental,
          edge15: true,
          firefox2: false,
          firefox52: true,
          opera10_50: false,
          safari10_1: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'no line break between async and function',
        exec: function () {/*
          async function a() {}
          try { Function ("async\n function a() {await 0}")(); } catch (e) { return true; }
        */},
        res: {
          tr: null,
          babel6corejs2: null,
          babel7corejs3: true,
          closure: true,
          typescript1corejs2: null,
          chrome52: null,
          chrome55: true,
          ie11: false,
          edge13: false,
          edge14: edge.experimental,
          edge15: true,
          firefox2: false,
          firefox52: true,
          opera10_50: false,
          safari10_1: true,
          duktape2_0: false,
          jerryscript2_3_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'no "prototype" property',
        exec: function () {/*
          async function a() {};
          return !a.hasOwnProperty("prototype");
        */},
        res: {
          tr: null,
          babel6corejs2: null,
          closure: false,
          typescript1corejs2: false,
          chrome52: null,
          chrome55: true,
          ie11: false,
          edge13: edge.experimental,
          edge15: true,
          firefox2: false,
          firefox52: true,
          opera10_50: false,
          safari10_1: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'await',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/await',
        exec: function () {/*
          (async function () {
            await Promise.resolve();
            var a1 = await new Promise(function (resolve) { setTimeout(resolve,800,"foo"); });
            var a2 = await new Promise(function (resolve) { setTimeout(resolve,800,"bar"); });
            if (a1 + a2 === "foobar") {
              asyncTestPassed();
            }
          }());
        */},
        res: {
          tr: true,
          babel6corejs2: babel.regenerator,
          closure: true,
          typescript1corejs2: typescript.downlevelIteration,
          chrome52: chrome.experimental,
          chrome55: true,
          ie11: false,
          edge13: edge.experimental,
          edge15: true,
          firefox2: false,
          firefox52: true,
          opera10_50: false,
          safari10_1: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'await, rejection',
        exec: function () {/*
          (async function () {
            await Promise.resolve();
            try {
              var a1 = await new Promise(function (_, reject) { setTimeout(reject,800,"foo"); });
            } catch (e) {
              if (e === "foo") {
                asyncTestPassed();
              }
            }
          }());
        */},
        res: {
          tr: null,
          babel6corejs2: null,
          babel7corejs2: babel.regenerator,
          closure: true,
          typescript1corejs2: typescript.downlevelIteration,
          chrome52: null,
          chrome55: true,
          ie11: false,
          edge13: edge.experimental,
          edge15: true,
          firefox2: false,
          firefox52: true,
          opera10_50: false,
          safari10_1: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'must await a value',
        exec: function () {/*
          async function a() { await Promise.resolve(); }
          try { Function ("(async function a() { await; }())")(); } catch (e) { return true; }
        */},
        res: {
          tr: null,
          babel6corejs2: null,
          babel7corejs3: true,
          closure: true,
          typescript1corejs2: null,
          chrome52: null,
          chrome55: true,
          ie11: false,
          edge13: edge.experimental,
          edge15: true,
          firefox2: false,
          firefox52: true,
          opera10_50: false,
          safari10_1: true,
          duktape2_0: false,
          jerryscript2_3_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'can await non-Promise values',
        exec: function () {/*
          (async function () {
            await Promise.resolve();
            var e = await "foo";
            if (e === "foo") {
              asyncTestPassed();
            }
          }());
        */},
        res: {
          tr: null,
          babel6corejs2: null,
          babel7corejs2: babel.regenerator,
          closure: true,
          typescript1corejs2: typescript.downlevelIteration,
          chrome52: null,
          chrome55: true,
          ie11: false,
          edge13: edge.experimental,
          edge15: true,
          firefox2: false,
          firefox52: true,
          opera10_50: false,
          safari10_1: true,
          duktape2_0: false,
          jerryscript2_3_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'cannot await in parameters',
        exec: function () {/*
          async function a() { await Promise.resolve(); }
          try { Function ("(async function a(b = await Promise.resolve()) {}())")(); } catch (e) { return true; }
        */},
        res: {
          tr: null,
          babel6corejs2: null,
          babel7corejs3: true,
          closure: false,
          closure20200614: true,
          typescript1corejs2: null,
          chrome52: null,
          chrome55: true,
          ie11: false,
          edge13: edge.experimental,
          edge15: true,
          firefox2: false,
          firefox52: true,
          opera10_50: false,
          safari10_1: true,
          duktape2_0: false,
          jerryscript2_3_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'async methods, object literals',
        exec: function () {/*
          var o = {
            async a() { return await Promise.resolve("foo"); }
          };
          var p = o.a();
          if (!(p instanceof Promise)) {
            return false;
          }
          p.then(function (result) {
            if (result === "foo") {
              asyncTestPassed();
            }
          });
        */},
        res: {
          tr: null,
          babel6corejs2: null,
          babel7corejs2: babel.regenerator,
          closure: true,
          typescript1corejs2: typescript.downlevelIteration,
          chrome52: null,
          chrome55: true,
          ie11: false,
          edge13: edge.experimental,
          edge15: true,
          firefox2: false,
          firefox52: true,
          opera10_50: false,
          safari10_1: true,
          duktape2_0: false,
          jerryscript2_3_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'async methods, classes',
        exec: function () {/*
          class C {
            async a() { return await Promise.resolve("foo"); }
          };
          var p = new C().a();
          if (!(p instanceof Promise)) {
            return false;
          }
          p.then(function (result) {
            if (result === "foo") {
              asyncTestPassed();
            }
          });
        */},
        res: {
          tr: null,
          babel6corejs2: null,
          babel7corejs2: babel.regenerator,
          closure: true,
          typescript1corejs2: typescript.downlevelIteration,
          chrome52: null,
          chrome55: true,
          ie11: false,
          edge13: edge.experimental,
          edge15: true,
          firefox2: false,
          firefox52: true,
          opera10_50: false,
          safari10_1: true,
          duktape2_0: false,
          jerryscript2_3_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'async arrow functions in methods, classes',
        exec: function () {/*
          function doSomething(callback) {
            callback();
          }
          class C {
            a() {
              doSomething(async () => {
                await 1;
                asyncTestPassed();
              });
            }
          };
          var p = new C().a();
        */},
        res: {
          tr: true,
          babel6corejs2: babel.regenerator,
          closure: true,
          typescript1corejs2: typescript.downlevelIteration,
          chrome52: chrome.experimental,
          chrome55: true,
          ie11: false,
          edge13: edge.experimental,
          edge15: true,
          firefox2: false,
          firefox52: true,
          opera10_50: false,
          safari10: false,
          safari10_1: false,
          safari11: true,
          duktape2_0: false,
          jerryscript2_3_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'async arrow functions',
        exec: function () {/*
          var a = async () => await Promise.resolve("foo");
          var p = a();
          if (!(p instanceof Promise)) {
            return false;
          }
          p.then(function (result) {
            if (result === "foo") {
              asyncTestPassed();
            }
          });
        */},
        res: {
          tr: true,
          babel6corejs2: babel.regenerator,
          closure: true,
          typescript1corejs2: typescript.downlevelIteration,
          chrome52: chrome.experimental,
          chrome55: true,
          ie11: false,
          edge13: edge.experimental,
          edge15: true,
          firefox2: false,
          firefox52: true,
          opera10_50: false,
          safari10_1: true,
          duktape2_0: false,
          jerryscript2_3_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'correct prototype chain',
        exec: function () {/*
          var asyncFunctionProto = Object.getPrototypeOf(async function () {});
          return asyncFunctionProto !== function () {}.prototype
            && Object.getPrototypeOf(asyncFunctionProto) === Function.prototype;
        */},
        res: {
          tr: null,
          babel6corejs2: null,
          closure: false,
          typescript1corejs2: false,
          chrome52: null,
          chrome55: true,
          ie11: false,
          edge13: false,
          edge14: edge.experimental,
          edge15: true,
          firefox2: false,
          firefox52: true,
          opera10_50: false,
          safari10_1: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'async function prototype, Symbol.toStringTag',
        exec: function () {/*
          return Object.getPrototypeOf(async function () {})[Symbol.toStringTag] === "AsyncFunction";
        */},
        res: {
          tr: null,
          babel6corejs2: null,
          closure: false,
          typescript1corejs2: false,
          chrome52: null,
          chrome55: true,
          ie11: false,
          edge13: false,
          edge15: true,
          firefox2: false,
          firefox52: true,
          opera10_50: false,
          safari10_1: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'async function constructor',
        exec: function () {/*
          var a = async function () {}.constructor("return 'foo';");
          var p = a();
          if (!(p instanceof Promise)) {
            return false;
          }
          p.then(function (result) {
            if (result === "foo") {
              asyncTestPassed();
            }
          });
        */},
        res: {
          tr: null,
          babel6corejs2: null,
          closure: false,
          typescript1corejs2: false,
          chrome52: null,
          chrome55: true,
          ie11: false,
          edge13: false,
          edge14: edge.experimental,
          edge15: true,
          firefox2: false,
          firefox52: true,
          opera10_50: false,
          safari10_1: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      }
    ]
  },
  {
    name: 'shared memory and atomics',
    category: '2017 features',
    significance: 'medium',
    'subtests': [
      {
        name: 'SharedArrayBuffer',
        spec: 'https://tc39.github.io/ecma262/#sec-sharedarraybuffer-objects',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer',
        exec: function () {/*
         return typeof SharedArrayBuffer === 'function';
         */},
        res: {
          ie11: false,
          edge15: edge.experimental,
          edge16: true,
          edge17: {
            val: false,
            note_id: 'edg-shared-memory-spectre',
            note_html: 'The feature was temporarily disabled to mitigate the Meltdown and Spectre CPU bugs.'
          },
          firefox2: false,
          firefox46: firefox.nightly,
          firefox51: firefox.developer,
          firefox53: firefox.sharedmem,
          firefox55: true,
          firefox57: {
            val: "flagged",
            note_id: 'fx-shared-memory-spectre',
            note_html: 'The feature was <a href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/">temporarily disabled</a> to mitigate the Meltdown and Spectre CPU bugs. It can be enabled via <code>javascript.options.shared_memory</code> setting under <code>about:config</code>'
          },
          firefox72: firefox.nightly,
          firefox74: firefox.beta,
          firefox77: {
            val: false,
            note_id: "fx-shared-memory-esr-disable",
            note_html: 'The feature was intentionally disabled to prepare for Firefox 78 ESR'
          },
          firefox79: {
            val: true,
            note_id: "fx-shared-memory-cors-isolation",
            note_html: 'The feature is available with <a href="https://hacks.mozilla.org/2020/07/safely-reviving-shared-memory/">properly set CORS isolation headers</a> or via enabling <code>dom.postMessage.sharedArrayBuffer.bypassCOOP_COEP.insecure.enabled</code> setting under <code>about:config</code>'
          },
          opera10_50: false,
          chrome48: chrome.sharedmem,
          chrome60: true,
          chrome63: {
            val: false,
            note_id: 'chr-shared-memory-spectre',
            note_html: 'The feature was temporarily disabled to mitigate the Meltdown and Spectre CPU bugs.'
          },
          chrome68: true,
          safari10_1: true,
          safari11: {
            val: false,
            note_id: 'sf-shared-memory-spectre',
            note_html: 'The feature was <a href="https://webkit.org/blog/8048/what-spectre-and-meltdown-mean-for-webkit/">temporarily disabled</a> to mitigate the Meltdown and Spectre CPU bugs.'
          },
          safari15_2: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'SharedArrayBuffer[Symbol.species]',
        exec: function () {/*
         return SharedArrayBuffer[Symbol.species] === SharedArrayBuffer;
         */},
        res: {
          ie11: false,
          edge15: edge.experimental,
          edge16: true,
          edge17: { val: false, note_id: 'edg-shared-memory-spectre' },
          firefox2: false,
          firefox52: firefox.developer,
          firefox53: firefox.sharedmem,
          firefox55: true,
          firefox57: { val: "flagged", note_id: 'fx-shared-memory-spectre' },
          firefox72: firefox.nightly,
          firefox74: firefox.beta,
          firefox77: {val: false, note_id: "fx-shared-memory-esr-disable" },
          firefox79: {val: true, note_id: "fx-shared-memory-cors-isolation" },
          opera10_50: false,
          chrome60: true,
          chrome63: { val: false, note_id: 'chr-shared-memory-spectre' },
          chrome68: true,
          safari10_1: true,
          safari11: { val: false, note_id: 'sf-shared-memory-spectre' },
          safari15_2: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'SharedArrayBuffer.prototype.byteLength',
        spec: 'https://tc39.github.io/ecma262/#sec-get-sharedarraybuffer.prototype.bytelength',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer/byteLength',
        exec: function () {/*
         return 'byteLength' in SharedArrayBuffer.prototype;
         */},
        res: {
          ie11: false,
          edge15: edge.experimental,
          edge16: true,
          edge17: { val: false, note_id: 'edg-shared-memory-spectre' },
          firefox2: false,
          firefox46: firefox.nightly,
          firefox51: firefox.developer,
          firefox53: firefox.sharedmem,
          firefox55: true,
          firefox57: { val: "flagged", note_id: 'fx-shared-memory-spectre' },
          firefox72: firefox.nightly,
          firefox74: firefox.beta,
          firefox77: {val: false, note_id: "fx-shared-memory-esr-disable" },
          firefox79: {val: true, note_id: "fx-shared-memory-cors-isolation" },
          opera10_50: false,
          chrome48: chrome.sharedmem,
          chrome60: true,
          chrome63: { val: false, note_id: 'chr-shared-memory-spectre' },
          chrome68: true,
          safari11: { val: false, note_id: 'sf-shared-memory-spectre' },
          safari15_2: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'SharedArrayBuffer.prototype.slice',
        spec: 'https://tc39.github.io/ecma262/#sec-sharedarraybuffer.prototype.slice',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer/slice',
        exec: function () {/*
         return typeof SharedArrayBuffer.prototype.slice === 'function';
         */},
        res: {
          ie11: false,
          edge15: edge.experimental,
          edge16: true,
          edge17: { val: false, note_id: 'edg-shared-memory-spectre' },
          firefox2: false,
          firefox52: firefox.developer,
          firefox53: firefox.sharedmem,
          firefox55: true,
          firefox57: { val: "flagged", note_id: 'fx-shared-memory-spectre' },
          firefox72: firefox.nightly,
          firefox74: firefox.beta,
          firefox77: {val: false, note_id: "fx-shared-memory-esr-disable" },
          firefox79: {val: true, note_id: "fx-shared-memory-cors-isolation" },
          opera10_50: false,
          chrome60: true,
          chrome63: { val: false, note_id: 'chr-shared-memory-spectre' },
          chrome68: true,
          safari10_1: true,
          safari11: { val: false, note_id: 'sf-shared-memory-spectre' },
          safari15_2: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'SharedArrayBuffer.prototype[Symbol.toStringTag]',
        spec: 'https://tc39.github.io/ecma262/#sec-sharedarraybuffer.prototype.toString',
        exec: function () {/*
         return SharedArrayBuffer.prototype[Symbol.toStringTag] === 'SharedArrayBuffer';
         */},
        res: {
          ie11: false,
          edge15: edge.experimental,
          edge16: true,
          edge17: { val: false, note_id: 'edg-shared-memory-spectre' },
          firefox2: false,
          firefox52: firefox.developer,
          firefox53: firefox.sharedmem,
          firefox55: true,
          firefox57: { val: "flagged", note_id: 'fx-shared-memory-spectre' },
          firefox72: firefox.nightly,
          firefox74: firefox.beta,
          firefox77: {val: false, note_id: "fx-shared-memory-esr-disable" },
          firefox79: {val: true, note_id: "fx-shared-memory-cors-isolation" },
          opera10_50: false,
          chrome48: chrome.sharedmem,
          chrome60: true,
          chrome63: { val: false, note_id: 'chr-shared-memory-spectre' },
          chrome68: true,
          safari10_1: true,
          safari11: { val: false, note_id: 'sf-shared-memory-spectre' },
          safari15_2: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Atomics.add',
        spec: 'https://tc39.github.io/ecma262/#sec-atomics.add',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Atomics/add',
        exec: function () {/*
         return typeof Atomics.add === 'function';
         */},
        res: {
          ie11: false,
          edge15: edge.experimental,
          edge16: true,
          edge17: { val: false, note_id: 'edg-shared-memory-spectre' },
          firefox2: false,
          firefox46: firefox.nightly,
          firefox51: firefox.developer,
          firefox53: firefox.sharedmem,
          firefox55: true,
          firefox57: { val: "flagged", note_id: 'fx-shared-memory-spectre' },
          firefox72: firefox.nightly,
          firefox74: firefox.beta,
          firefox78: true,
          opera10_50: false,
          chrome48: chrome.sharedmem,
          chrome60: true,
          chrome63: { val: false, note_id: 'chr-shared-memory-spectre' },
          chrome68: true,
          safari10_1: true,
          safari11_1: { val: false, note_id: 'sf-shared-memory-spectre' },
          safari15_2: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Atomics.and',
        spec: 'https://tc39.github.io/ecma262/#sec-atomics.and',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Atomics/and',
        exec: function () {/*
         return typeof Atomics.and === 'function';
         */},
        res: {
          ie11: false,
          edge15: edge.experimental,
          edge16: true,
          edge17: { val: false, note_id: 'edg-shared-memory-spectre' },
          firefox2: false,
          firefox46: firefox.nightly,
          firefox51: firefox.developer,
          firefox53: firefox.sharedmem,
          firefox55: true,
          firefox57: { val: "flagged", note_id: 'fx-shared-memory-spectre' },
          firefox72: firefox.nightly,
          firefox74: firefox.beta,
          firefox78: true,
          opera10_50: false,
          chrome48: chrome.sharedmem,
          chrome60: true,
          chrome63: { val: false, note_id: 'chr-shared-memory-spectre' },
          chrome68: true,
          safari10_1: true,
          safari11_1: { val: false, note_id: 'sf-shared-memory-spectre' },
          safari15_2: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Atomics.compareExchange',
        spec: 'https://tc39.github.io/ecma262/#sec-atomics.compareExchange',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Atomics/compareExchange',
        exec: function () {/*
         return typeof Atomics.compareExchange === 'function';
         */},
        res: {
          ie11: false,
          edge15: edge.experimental,
          edge16: true,
          edge17: { val: false, note_id: 'edg-shared-memory-spectre' },
          firefox2: false,
          firefox46: firefox.nightly,
          firefox51: firefox.developer,
          firefox53: firefox.sharedmem,
          firefox55: true,
          firefox57: { val: "flagged", note_id: 'fx-shared-memory-spectre' },
          firefox72: firefox.nightly,
          firefox74: firefox.beta,
          firefox78: true,
          opera10_50: false,
          chrome48: chrome.sharedmem,
          chrome60: true,
          chrome63: { val: false, note_id: 'chr-shared-memory-spectre' },
          chrome68: true,
          safari10_1: true,
          safari11_1: { val: false, note_id: 'sf-shared-memory-spectre' },
          safari15_2: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Atomics.exchange',
        spec: 'https://tc39.github.io/ecma262/#sec-atomics.exchange',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Atomics/exchange',
        exec: function () {/*
         return typeof Atomics.exchange === 'function';
         */},
        res: {
          ie11: false,
          edge15: edge.experimental,
          edge16: true,
          edge17: { val: false, note_id: 'edg-shared-memory-spectre' },
          firefox2: false,
          firefox46: firefox.nightly,
          firefox51: firefox.developer,
          firefox53: firefox.sharedmem,
          firefox55: true,
          firefox57: { val: "flagged", note_id: 'fx-shared-memory-spectre' },
          firefox72: firefox.nightly,
          firefox74: firefox.beta,
          firefox78: true,
          opera10_50: false,
          chrome48: chrome.sharedmem,
          chrome60: true,
          chrome63: { val: false, note_id: 'chr-shared-memory-spectre' },
          chrome68: true,
          safari10_1: true,
          safari11_1: { val: false, note_id: 'sf-shared-memory-spectre' },
          safari15_2: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Atomics.wait',
        spec: 'https://tc39.github.io/ecma262/#sec-atomics.wait',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Atomics/wait',
        exec: function () {/*
         return typeof Atomics.wait === 'function';
         */},
        res: {
          ie11: false,
          edge15: edge.experimental,
          edge16: true,
          edge17: { val: false, note_id: 'edg-shared-memory-spectre' },
          firefox2: false,
          firefox48: firefox.nightly,
          firefox51: firefox.developer,
          firefox53: firefox.sharedmem,
          firefox55: true,
          firefox57: { val: "flagged", note_id: 'fx-shared-memory-spectre' },
          firefox72: firefox.nightly,
          firefox74: firefox.beta,
          firefox78: true,
          opera10_50: false,
          chrome48: chrome.sharedmem,
          chrome60: true,
          chrome63: { val: false, note_id: 'chr-shared-memory-spectre' },
          chrome68: true,
          safari10_1: true,
          safari11_1: { val: false, note_id: 'sf-shared-memory-spectre' },
          safari15_2: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Atomics.notify',
        spec: 'https://tc39.github.io/ecma262/#sec-atomics.notify',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Atomics/notify',
        exec: function () {/*
         return typeof Atomics.notify === 'function';
         */},
        res: {
          ie11: false,
          edge15: edge.experimental,
          edge16: true,
          edge17: { val: false, note_id: 'edg-shared-memory-spectre' },
          firefox2: false,
          firefox48: firefox.nightly,
          firefox51: firefox.developer,
          firefox53: firefox.sharedmem,
          firefox55: true,
          firefox57: { val: "flagged", note_id: 'fx-shared-memory-spectre' },
          firefox72: firefox.nightly,
          firefox74: firefox.beta,
          firefox78: true,
          opera10_50: false,
          chrome48: chrome.sharedmem,
          chrome60: true,
          chrome63: { val: false, note_id: 'chr-shared-memory-spectre' },
          chrome68: true,
          safari10_1: true,
          safari11_1: { val: false, note_id: 'sf-shared-memory-spectre' },
          safari15_2: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: false,
          graalvm20: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Atomics.isLockFree',
        spec: 'https://tc39.github.io/ecma262/#sec-atomics.isLockFree',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Atomics/isLockFree',
        exec: function () {/*
         return typeof Atomics.isLockFree === 'function';
         */},
        res: {
          ie11: false,
          edge15: edge.experimental,
          edge16: true,
          edge17: { val: false, note_id: 'edg-shared-memory-spectre' },
          firefox2: false,
          firefox46: firefox.nightly,
          firefox51: firefox.developer,
          firefox53: firefox.sharedmem,
          firefox55: true,
          firefox57: { val: "flagged", note_id: 'fx-shared-memory-spectre' },
          firefox72: firefox.nightly,
          firefox74: firefox.beta,
          firefox78: true,
          opera10_50: false,
          chrome48: chrome.sharedmem,
          chrome60: true,
          chrome63: { val: false, note_id: 'chr-shared-memory-spectre' },
          chrome68: true,
          safari10_1: true,
          safari11_1: { val: false, note_id: 'sf-shared-memory-spectre' },
          safari15_2: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Atomics.load',
        spec: 'https://tc39.github.io/ecma262/#sec-atomics.load',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Atomics/load',
        exec: function () {/*
         return typeof Atomics.load === 'function';
         */},
        res: {
          ie11: false,
          edge15: edge.experimental,
          edge16: true,
          edge17: { val: false, note_id: 'edg-shared-memory-spectre' },
          firefox2: false,
          firefox46: firefox.nightly,
          firefox51: firefox.developer,
          firefox53: firefox.sharedmem,
          firefox55: true,
          firefox57: { val: "flagged", note_id: 'fx-shared-memory-spectre' },
          firefox72: firefox.nightly,
          firefox74: firefox.beta,
          firefox78: true,
          opera10_50: false,
          chrome48: chrome.sharedmem,
          chrome60: true,
          chrome63: { val: false, note_id: 'chr-shared-memory-spectre' },
          chrome68: true,
          safari10_1: true,
          safari11_1: { val: false, note_id: 'sf-shared-memory-spectre' },
          safari15_2: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Atomics.or',
        spec: 'https://tc39.github.io/ecma262/#sec-atomics.or',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Atomics/or',
        exec: function () {/*
         return typeof Atomics.or === 'function';
         */},
        res: {
          ie11: false,
          edge15: edge.experimental,
          edge16: true,
          edge17: { val: false, note_id: 'edg-shared-memory-spectre' },
          firefox2: false,
          firefox46: firefox.nightly,
          firefox51: firefox.developer,
          firefox53: firefox.sharedmem,
          firefox55: true,
          firefox57: { val: "flagged", note_id: 'fx-shared-memory-spectre' },
          firefox72: firefox.nightly,
          firefox74: firefox.beta,
          firefox78: true,
          opera10_50: false,
          chrome48: chrome.sharedmem,
          chrome60: true,
          chrome63: { val: false, note_id: 'chr-shared-memory-spectre' },
          chrome68: true,
          safari10_1: true,
          safari11_1: { val: false, note_id: 'sf-shared-memory-spectre' },
          safari15_2: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Atomics.store',
        spec: 'https://tc39.github.io/ecma262/#sec-atomics.store',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Atomics/store',
        exec: function () {/*
         return typeof Atomics.store === 'function';
         */},
        res: {
          ie11: false,
          edge15: edge.experimental,
          edge16: true,
          edge17: { val: false, note_id: 'edg-shared-memory-spectre' },
          firefox2: false,
          firefox46: firefox.nightly,
          firefox51: firefox.developer,
          firefox53: firefox.sharedmem,
          firefox55: true,
          firefox57: { val: "flagged", note_id: 'fx-shared-memory-spectre' },
          firefox72: firefox.nightly,
          firefox74: firefox.beta,
          firefox78: true,
          opera10_50: false,
          chrome48: chrome.sharedmem,
          chrome60: true,
          chrome63: { val: false, note_id: 'chr-shared-memory-spectre' },
          chrome68: true,
          safari10_1: true,
          safari11_1: { val: false, note_id: 'sf-shared-memory-spectre' },
          safari15_2: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Atomics.sub',
        spec: 'https://tc39.github.io/ecma262/#sec-atomics.sub',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Atomics/sub',
        exec: function () {/*
         return typeof Atomics.sub === 'function';
         */},
        res: {
          ie11: false,
          edge15: edge.experimental,
          edge16: true,
          edge17: { val: false, note_id: 'edg-shared-memory-spectre' },
          firefox2: false,
          firefox46: firefox.nightly,
          firefox51: firefox.developer,
          firefox53: firefox.sharedmem,
          firefox55: true,
          firefox57: { val: "flagged", note_id: 'fx-shared-memory-spectre' },
          firefox72: firefox.nightly,
          firefox74: firefox.beta,
          firefox78: true,
          opera10_50: false,
          chrome48: chrome.sharedmem,
          chrome60: true,
          chrome63: { val: false, note_id: 'chr-shared-memory-spectre' },
          chrome68: true,
          safari10_1: true,
          safari11_1: { val: false, note_id: 'sf-shared-memory-spectre' },
          safari15_2: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Atomics.xor',
        spec: 'https://tc39.github.io/ecma262/#sec-atomics.xor',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Atomics/xor',
        exec: function () {/*
         return typeof Atomics.xor === 'function';
         */},
        res: {
          ie11: false,
          edge15: edge.experimental,
          edge16: true,
          edge17: { val: false, note_id: 'edg-shared-memory-spectre' },
          firefox2: false,
          firefox46: firefox.nightly,
          firefox51: firefox.developer,
          firefox53: firefox.sharedmem,
          firefox55: true,
          firefox57: { val: "flagged", note_id: 'fx-shared-memory-spectre' },
          firefox72: firefox.nightly,
          firefox74: firefox.beta,
          firefox78: true,
          opera10_50: false,
          chrome48: chrome.sharedmem,
          chrome60: true,
          chrome63: { val: false, note_id: 'chr-shared-memory-spectre' },
          chrome68: true,
          safari10_1: true,
          safari11_1: { val: false, note_id: 'sf-shared-memory-spectre' },
          safari15_2: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      }
    ]
  },
  {
    name: 'generator functions can\'t be used with "new"',
    category: '2016 misc',
    significance: 'tiny',
    spec: 'http://www.ecma-international.org/ecma-262/7.0/index.html#sec-createdynamicfunction',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function*#Generators_are_not_constructable',
    links: [
      {
        note_id: 'new-gen-fn',
        note_html: '<a href="https://github.com/rwaldron/tc39-notes/blob/master/es7/2015-07/july-28.md#67-new--generatorfunction">TC39 meeting notes from July 28, 2015.</a>'
      }
    ],
    exec: function () {/*
      function * generator() {
        yield 3;
      }
      try {
        new generator();
      } catch (e) {
        return true;
      }
    */},
    res: {
      ie11: false,
      edge13: true,
      firefox2: false,
      firefox43: true,
      opera10_50: false,
      chrome50: true,
      safari10: true,
      duktape2_0: false,
      jerryscript2_3_0: true,
      graalvm19: true,
      hermes0_7_0: true,
      reactnative0_70_3: true,
      rhino1_7_13: false
    }
  },
  {
    name: 'generator throw() caught by inner generator',
    category: '2016 misc',
    significance: 'tiny',
    spec: 'http://www.ecma-international.org/ecma-262/7.0/index.html#sec-generatorfunction-objects',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function*#IteratorResult_object_returned_instead_of_throwing',
    links: [
      {
        note_id: 'gen-throw',
        note_html: '<a href="https://github.com/tc39/ecma262/issues/293">\'Semantics of yield* in throw case\' GitHub issue in ECMA-262 repo.</a>'
      }
    ],
    exec: function () {/*
      function * generator() {
        yield * (function * () {
          try {
            yield 'foo';
          }
          catch (e) {
            return;
          }
        }());
        yield 'bar';
      }
      var iter = generator();
      iter.next();
      return iter['throw']().value === 'bar';
    */},
    res: {
      babel7corejs3: true,
      closure: false,
      closure20180319: true,
      typescript1corejs2: typescript.downlevelIteration,
      ie11: false,
      edge14: true,
      firefox2: false,
      firefox27: true,
      opera10_50: false,
      chrome39: true,
      node0_12: "flagged",
      node4: true,
      safari10: true,
      duktape2_0: false,
      jerryscript2_3_0: true,
      graalvm19: true,
      hermes0_7_0: true,
      reactnative0_70_3: true,
      rhino1_7_13: true
    }
  },
  {
    name: 'strict fn w/ non-strict non-simple params is error',
    category: '2016 misc',
    significance: 'tiny',
    spec: 'http://www.ecma-international.org/ecma-262/7.0/index.html#sec-functiondeclarationinstantiation',
    links: [
      {
        note_id: 'strict-fn-non-strict-params',
        note_html: '<a href="https://github.com/rwaldron/tc39-notes/blob/master/es7/2015-07/july-29.md#611-the-scope-of-use-strict-with-respect-to-destructuring-in-parameter-lists">TC39 meeting notes from July 29, 2015.</a>'
      }
    ],
    exec: function () {/*
      function foo(...a) {}
      try {
        Function ("function bar(...a) {'use strict';}")();
      } catch (e) {
      return true;
      }
     */},
    res: {
      babel7corejs3: true,
      ie11: false,
      edge12: true,
      firefox2: false,
      firefox52: true,
      opera10_50: false,
      chrome47: true,
      safari10: true,
      duktape2_0: false,
      jerryscript2_3_0: true,
      graalvm19: true,
      hermes0_7_0: true,
      reactnative0_70_3: true,
      rhino1_7_13: false
    }
  },
  {
    name: 'nested rest destructuring, declarations',
    category: '2016 misc',
    significance: 'tiny',
    spec: 'http://www.ecma-international.org/ecma-262/7.0/index.html#sec-destructuring-assignment',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment#Nested_object_and_array_destructuring',
    links: [
      {
        note_id: 'nested-rest-destruct-decl',
        note_html: '<a href="https://github.com/rwaldron/tc39-notes/blob/master/es7/2015-07/july-28.md#66-bindingrestelement-should-allow-a-bindingpattern-ala-assignmentrestelement">TC39 meeting notes from July 28, 2015.</a>'
      }
    ],
    exec: function () {/*
      var [x, ...[y, ...z]] = [1,2,3,4];
      return x === 1 && y === 2 && z + '' === '3,4';
    */},
    res: {
      babel6corejs2: true,
      closure: true,
      ie11: false,
      edge13: edge.experimental,
      edge14: true,
      firefox2: false,
      firefox47: true,
      opera10_50: false,
      chrome49: true,
      safari10_1: true,
      typescript1corejs2: true,
      duktape2_0: false,
      jerryscript2_3_0: true,
      graalvm19: true,
      hermes0_7_0: true,
      reactnative0_70_3: true,
      rhino1_7_13: false
    }
  },
  {
    name: 'nested rest destructuring, parameters',
    category: '2016 misc',
    significance: 'tiny',
    spec: 'http://www.ecma-international.org/ecma-262/7.0/index.html#sec-destructuring-assignment',
    links: [
      {
        note_id: 'nested-rest-destruct-params',
        note_html: '<a href="https://github.com/rwaldron/tc39-notes/blob/master/es7/2015-07/july-28.md#66-bindingrestelement-should-allow-a-bindingpattern-ala-assignmentrestelement">TC39 meeting notes from July 28, 2015.</a>'
      }
    ],
    exec: function () {/*
      return function ([x, ...[y, ...z]]) {
        return x === 1 && y === 2 && z + '' === '3,4';
      }([1,2,3,4]);
    */},
    res: {
      babel6corejs2: true,
      closure: true,
      ie11: false,
      edge13: edge.experimental,
      edge14: true,
      firefox2: false,
      firefox47: true,
      opera10_50: false,
      typescript1corejs2: true,
      chrome49: true,
      safari10_1: true,
      duktape2_0: false,
      jerryscript2_3_0: true,
      graalvm19: true,
      hermes0_7_0: true,
      reactnative0_70_3: true,
      rhino1_7_13: false
    }
  },
  {
    name: 'Proxy, "enumerate" handler removed',
    category: '2016 misc',
    significance: 'tiny',
    spec: 'http://www.ecma-international.org/ecma-262/7.0/index.html#sec-proxy-objects',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Proxy/handler/enumerate',
    links: [
      {
        note_id: 'proxy-enumerate-removed',
        note_html: '<a href="https://github.com/tc39/ecma262/pull/367">\'Normative: Remove [[Enumerate]] and associated reflective capabilities\' GitHub Pull Request in ECMA-262 repo.</a>'
      }
    ],
    exec: function () {/*
      var passed = true;
      var proxy = new Proxy({}, {
        enumerate: function () {
          passed = false;
        }
      });
      for (var key in proxy); // Should not throw, nor execute the 'enumerate' method.
      return passed;
    */},
    res: {
      ie11: false,
      edge15: true,
      firefox2: false,
      firefox18: true,
      firefox25: false,
      firefox47: true,
      opera10_50: false,
      chrome50: true,
      safari10: true,
      duktape2_0: true,
      jerryscript2_3_0: false,
      jerryscript2_4_0: true,
      graalvm19: true,
      hermes0_7_0: true,
      reactnative0_70_3: true,
      rhino1_7_13: false
    }
  },
  {
    name: 'Proxy internal calls, Array.prototype.includes',
    category: '2016 misc',
    significance: 'tiny',
    spec: 'http://www.ecma-international.org/ecma-262/7.0/index.html#sec-array.prototype.includes',
    exec: function () {/*
     // Array.prototype.includes -> Get -> [[Get]]
     var get = [];
     var p = new Proxy({length: 3, 0: '', 1: '', 2: '', 3: ''}, { get: function (o, k) { get.push(k); return o[k]; }});
     Array.prototype.includes.call(p, {});
     if (get + '' !== "length,0,1,2") return;

     get = [];
     p = new Proxy({length: 4, 0: NaN, 1: '', 2: NaN, 3: ''}, { get: function (o, k) { get.push(k); return o[k]; }});
     Array.prototype.includes.call(p, NaN, 1);
     return (get + '' === "length,1,2");
     */},
    res: {
      firefox2: false,
      firefox43: true,
      opera10_50: false,
      chrome49: true,
      ie11: false,
      edge14: true,
      safari10: true,
      duktape2_0: false,
      jerryscript2_3_0: false,
      jerryscript2_4_0: true,
      graalvm19: true,
      hermes0_7_0: true,
      reactnative0_70_3: true,
      rhino1_7_13: false
    }
  },
  {
    name: 'Object.prototype getter/setter methods',
    spec: 'https://tc39.github.io/ecma262/#sec-object.prototype.__defineGetter__',
    category: '2017 annex b',
    significance: 'tiny',
    subtests: [{
      name: '__defineGetter__',
      mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/__defineGetter__',
      exec: function () {/*
       var obj = {};
       function bar() { return "bar"; }
       Object.prototype.__defineGetter__.call(obj, "foo", bar);
       var prop = Object.getOwnPropertyDescriptor(obj, "foo");
       return prop.get === bar && !prop.writable && prop.configurable
       && prop.enumerable;
       */},
      res: {
        babel6corejs2: babel.corejs,
        typescript1corejs2: typescript.corejs,
        ie11: true,
        firefox2: false,
        firefox4: true,
        opera10_50: false,
        opera12: true,
        chrome30: true,
        node0_12: true,
        safari4: true,
        safari9: true,
        android4_0: true,
        ios5_1: true,
        duktape2_0: false,
        duktape2_2: true,
        jerryscript2_3_0: false,
        jerryscript2_4_0: true,
        graalvm19: true,
        hermes0_7_0: true,
        reactnative0_70_3: true,
        rhino1_7_13: true
      }
    },
      {
        name: '__defineGetter__, symbols',
        exec: function () {/*
         var obj = {};
         var sym = Symbol();
         function bar() { return "bar"; }
         Object.prototype.__defineGetter__.call(obj, sym, bar);
         var prop = Object.getOwnPropertyDescriptor(obj, sym);
         return prop.get === bar && !prop.writable && prop.configurable
         && prop.enumerable;
         */},
        res: {
          babel6corejs2: babel.corejs,
          typescript1corejs2: typescript.corejs,
          ie11: false,
          edge12: true,
          firefox2: false,
          firefox36: true,
          opera10_50: false,
          chrome30: chrome.experimental,
          chrome38: true,
          node0_12: true,
          safari9: true,
          android4_0: true,
          duktape2_0: false,
          duktape2_2: true,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: '__defineGetter__, ToObject(this)',
        exec: function () {/*
          var key = '__accessors_test__';
          __defineGetter__.call(1, key, function () {});
          try {
            __defineGetter__.call(null, key, function () {});
          } catch (e) {
          return true;
          }
         */},
        res: {
          babel6corejs2: babel.corejs,
          typescript1corejs2: typescript.corejs,
          ie11: false,
          edge16: true,
          firefox2: false,
          firefox48: true,
          opera10_50: false,
          opera12: true,
          chrome60: chrome.harmony,
          chrome62: true,
          safari5_1: true,
          safari9: true,
          duktape2_0: false,
          duktape2_2: true,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: true
        }
      },
      {
        name: '__defineSetter__',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/__defineSetter__',
        exec: function () {/*
         var obj = {};
         function bar() {}
         Object.prototype.__defineSetter__.call(obj, "foo", bar);
         var prop = Object.getOwnPropertyDescriptor(obj, "foo");
         return prop.set === bar && !prop.writable && prop.configurable
         && prop.enumerable;
         */},
        res: {
          babel6corejs2: babel.corejs,
          typescript1corejs2: typescript.corejs,
          ie11: true,
          firefox2: false,
          firefox4: true,
          opera10_50: false,
          opera12: true,
          chrome30: true,
          node0_12: true,
          safari4: true,
          safari9: true,
          android4_0: true,
          ios5_1: true,
          duktape2_0: false,
          duktape2_2: true,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: true
        }
      },
      {
        name: '__defineSetter__, symbols',
        exec: function () {/*
         var obj = {};
         var sym = Symbol();
         function bar(baz) {}
         Object.prototype.__defineSetter__.call(obj, sym, bar);
         var prop = Object.getOwnPropertyDescriptor(obj, sym);
         return prop.set === bar && !prop.writable && prop.configurable
         && prop.enumerable;
         */},
        res: {
          babel6corejs2: babel.corejs,
          typescript1corejs2: typescript.corejs,
          ie11: false,
          edge12: true,
          firefox2: false,
          firefox36: true,
          opera10_50: false,
          chrome30: chrome.experimental,
          chrome38: true,
          node0_12: true,
          safari9: true,
          android4_0: true,
          duktape2_0: false,
          duktape2_2: true,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: '__defineSetter__, ToObject(this)',
        exec: function () {/*
         var key = '__accessors_test__';
         __defineSetter__.call(1, key, function () {});
         try {
         __defineSetter__.call(null, key, function () {});
         } catch (e) {
         return true;
         }
         */},
        res: {
          babel6corejs2: babel.corejs,
          typescript1corejs2: typescript.corejs,
          ie11: false,
          edge16: true,
          firefox2: false,
          firefox48: true,
          opera10_50: false,
          opera12: true,
          chrome60: chrome.harmony,
          chrome62: true,
          safari5_1: true,
          safari9: true,
          duktape2_0: false,
          duktape2_2: true,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: true
        }
      },
      {
        name: '__lookupGetter__',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/__lookupGetter__',
        exec: function () {/*
         var obj = {
         get foo() { return "bar"},
         qux: 1
         };
         var foo = Object.prototype.__lookupGetter__.call(obj, "foo");
         return foo() === "bar"
         && Object.prototype.__lookupGetter__.call(obj, "qux") === void undefined
         && Object.prototype.__lookupGetter__.call(obj, "baz") === void undefined;
         */},
        res: {
          babel6corejs2: babel.corejs,
          typescript1corejs2: typescript.corejs,
          ie11: true,
          firefox2: true,
          opera10_50: true,
          opera12: true,
          chrome30: true,
          node0_12: true,
          safari3_1: true,
          safari9: true,
          android4_0: true,
          ios5_1: true,
          duktape2_0: false,
          duktape2_2: true,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: true
        }
      },
      {
        name: '__lookupGetter__, prototype chain',
        exec: function () {/*
         var obj = {
         get foo() { return "bar"},
         qux: 1
         };
         var foo = Object.prototype.__lookupGetter__.call(Object.create(obj), "foo");
         return foo() === "bar"
         && Object.prototype.__lookupGetter__.call(obj, "qux") === void undefined
         && Object.prototype.__lookupGetter__.call(obj, "baz") === void undefined;
         */},
        res: {
          babel6corejs2: babel.corejs,
          typescript1corejs2: typescript.corejs,
          ie11: true,
          firefox2: false,
          firefox4: true,
          opera10_50: false,
          opera12: true,
          chrome30: true,
          node0_12: true,
          safari4: true,
          safari9: true,
          android4_0: true,
          ios5_1: true,
          duktape2_0: false,
          duktape2_2: true,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: true
        }
      },
      {
        name: '__lookupGetter__, symbols',
        exec: function () {/*
          var sym = Symbol();
          var sym2 = Symbol();
          var obj = {};
          Object.defineProperty(obj, sym, { get: function () { return "bar"; }});
          Object.defineProperty(obj, sym2, { value: 1 });
          var foo = Object.prototype.__lookupGetter__.call(obj, sym);
          return foo() === "bar"
            && Object.prototype.__lookupGetter__.call(obj, sym2) === void undefined
            && Object.prototype.__lookupGetter__.call(obj, Symbol()) === void undefined;
        */},
        res: {
          babel6corejs2: babel.corejs,
          typescript1corejs2: typescript.corejs,
          ie11: false,
          edge12: true,
          firefox2: false,
          firefox36: true,
          opera10_50: false,
          chrome30: chrome.experimental,
          chrome38: true,
          node0_12: true,
          safari9: true,
          android4_0: true,
          duktape2_0: false,
          duktape2_2: true,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: '__lookupGetter__, ToObject(this)',
        exec: function () {/*
          __lookupGetter__.call(1, 'key');
          try {
            __lookupGetter__.call(null, 'key');
          } catch (e) {
            return true;
          }
        */},
        res: {
          babel6corejs2: babel.corejs,
          typescript1corejs2: typescript.corejs,
          ie11: true,
          firefox2: false,
          firefox24: true,
          opera10_50: false,
          opera12: true,
          chrome60: chrome.harmony,
          chrome62: true,
          safari5_1: true,
          safari9: true,
          duktape2_0: false,
          duktape2_2: true,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: '__lookupGetter__, data properties can shadow accessors',
        exec: function () {/*
          var a = {};
          var b = Object.create(a);
          b.foo = 1;
          a.__defineGetter__("foo", function () {});
          return b.__lookupGetter__("foo") === void undefined;
        */},
        res: {
          babel6corejs2: babel.corejs,
          typescript1corejs2: typescript.corejs,
          ie11: false,
          firefox2: false,
          firefox4: true,
          opera10_50: false,
          opera12: true,
          chrome57: true,
          node8: true,
          safari4: true,
          safari9: true,
          ios5_1: true,
          duktape2_0: false,
          duktape2_2: true,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: true
        }
      },
      {
        name: '__lookupSetter__',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/__lookupSetter__',
        exec: function () {/*
          var obj = {
            set foo(baz) { return "bar"; },
            qux: 1
          };
          var foo = Object.prototype.__lookupSetter__.call(obj, "foo");
          return foo() === "bar"
            && Object.prototype.__lookupSetter__.call(obj, "qux") === void undefined
            && Object.prototype.__lookupSetter__.call(obj, "baz") === void undefined;
        */},
        res: {
          babel6corejs2: babel.corejs,
          typescript1corejs2: typescript.corejs,
          ie11: true,
          firefox2: true,
          opera10_50: true,
          opera12: true,
          chrome30: true,
          node0_12: true,
          safari3_1: true,
          safari9: true,
          android4_0: true,
          ios5_1: true,
          duktape2_0: false,
          duktape2_2: true,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: true
        }
      },
      {
        name: '__lookupSetter__, prototype chain',
        exec: function () {/*
          var obj = {
            set foo(baz) { return "bar"; },
            qux: 1
          };
          var foo = Object.prototype.__lookupSetter__.call(Object.create(obj), "foo");
          return foo() === "bar"
            && Object.prototype.__lookupSetter__.call(obj, "qux") === void undefined
            && Object.prototype.__lookupSetter__.call(obj, "baz") === void undefined;
        */},
        res: {
          babel6corejs2: babel.corejs,
          typescript1corejs2: typescript.corejs,
          ie11: true,
          firefox2: false,
          firefox4: true,
          opera10_50: false,
          opera12: true,
          chrome30: true,
          node0_12: true,
          safari4: true,
          safari9: true,
          android4_0: true,
          ios5_1: true,
          duktape2_0: false,
          duktape2_2: true,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: true
        }
      },
      {
        name: '__lookupSetter__, symbols',
        exec: function () {/*
          var sym = Symbol();
          var sym2 = Symbol();
          var obj = {};
          Object.defineProperty(obj, sym, { set: function (baz) { return "bar"; }});
          Object.defineProperty(obj, sym2, { value: 1 });
          var foo = Object.prototype.__lookupSetter__.call(obj, sym);
          return foo() === "bar"
            && Object.prototype.__lookupSetter__.call(obj, sym2) === void undefined
            && Object.prototype.__lookupSetter__.call(obj, Symbol()) === void undefined;
        */},
        res: {
          babel6corejs2: babel.corejs,
          typescript1corejs2: typescript.corejs,
          ie11: false,
          edge12: true,
          firefox2: false,
          firefox36: true,
          opera10_50: false,
          chrome30: chrome.experimental,
          chrome38: true,
          node0_12: true,
          safari9: true,
          android4_0: true,
          duktape2_0: false,
          duktape2_2: true,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: '__lookupSetter__, ToObject(this)',
        exec: function () {/*
          __lookupSetter__.call(1, 'key');
          try {
            __lookupSetter__.call(null, 'key');
          } catch (e) {
            return true;
          }
        */},
        res: {
          babel6corejs2: babel.corejs,
          typescript1corejs2: typescript.corejs,
          ie11: true,
          firefox2: false,
          firefox24: true,
          opera10_50: false,
          opera12: true,
          chrome60: chrome.harmony,
          chrome62: true,
          safari5_1: true,
          safari9: true,
          duktape2_0: false,
          duktape2_2: true,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: '__lookupSetter__, data properties can shadow accessors',
        exec: function () {/*
          var a = {};
          var b = Object.create(a);
          b.foo = 1;
          a.__defineSetter__("foo", function () {})
          return b.__lookupSetter__("foo") === void undefined
        */},
        res: {
          babel6corejs2: babel.corejs,
          typescript1corejs2: typescript.corejs,
          ie11: false,
          firefox2: false,
          firefox4: true,
          opera10_50: false,
          opera12: true,
          chrome57: true,
          node8: true,
          safari4: true,
          safari9: true,
          ios5_1: true,
          duktape2_0: false,
          duktape2_2: true,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: true
        }
      }
    ]
  },
  {
    name: 'Proxy internal calls, getter/setter methods',
    spec: 'https://tc39.github.io/ecma262/#sec-object.prototype.__defineGetter__',
    category: '2017 annex b',
    significance: 'tiny',
    subtests: [{
      name: '__defineGetter__',
      exec: function () {/*
        // Object.prototype.__defineGetter__ -> DefinePropertyOrThrow -> [[DefineOwnProperty]]
        var def = [];
        var p = new Proxy({}, {
          defineProperty: function (o, v, desc) {
            def.push(v);
            Object.defineProperty(o, v, desc);
            return true;
          }
        });
        Object.prototype.__defineGetter__.call(p, "foo", Object);
        return def + '' === "foo";
      */},
      res: {
        firefox2: false,
        firefox18: true,
        opera10_50: false,
        ie11: false,
        edge13: true,
        chrome52: true,
        safari10: true,
        duktape2_0: false,
        jerryscript2_3_0: false,
        jerryscript2_4_0: true,
        graalvm19: true,
        hermes0_7_0: true,
        reactnative0_70_3: true,
        rhino1_7_13: false
      }
    },
      {
        name: '__defineSetter__',
        exec: function () {/*
          // Object.prototype.__defineSetter__ -> DefinePropertyOrThrow -> [[DefineOwnProperty]]
          var def = [];
          var p = new Proxy({}, {
            defineProperty: function (o, v, desc) {
              def.push(v);
              Object.defineProperty(o, v, desc);
              return true;
            }
          });
          Object.prototype.__defineSetter__.call(p, "foo", Object);
          return def + '' === "foo";
        */},
        res: {
          firefox2: false,
          firefox18: true,
          opera10_50: false,
          ie11: false,
          edge13: true,
          chrome52: true,
          safari10: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: '__lookupGetter__',
        exec: function () {/*
          // Object.prototype.__lookupGetter__ -> [[GetOwnProperty]]
          // Object.prototype.__lookupGetter__ -> [[GetPrototypeOf]]
          var gopd = [];
          var gpo = false;
          var p = new Proxy({}, {
            getPrototypeOf: function (o) {
              gpo = true;
              return Object.getPrototypeOf(o);
            },
            getOwnPropertyDescriptor: function (o, v) {
              gopd.push(v);
              return Object.getOwnPropertyDescriptor(o, v);
            }
          });
          Object.prototype.__lookupGetter__.call(p, "foo");
          return gopd + '' === "foo" && gpo;
        */},
        res: {
          ie11: false,
          edge14: true,
          chrome57: true,
          firefox2: false,
          firefox49: true,
          opera10_50: false,
          node8: true,
          safari10: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: '__lookupSetter__',
        exec: function () {/*
          // Object.prototype.__lookupSetter__ -> [[GetOwnProperty]]
          // Object.prototype.__lookupSetter__ -> [[GetPrototypeOf]]
          var gopd = [];
          var gpo = false;
          var p = new Proxy({}, {
            getPrototypeOf: function (o) {
              gpo = true;
              return Object.getPrototypeOf(o);
            },
            getOwnPropertyDescriptor: function (o, v) {
              gopd.push(v);
              return Object.getOwnPropertyDescriptor(o, v);
            }
          });
          Object.prototype.__lookupSetter__.call(p, "foo");
          return gopd + '' === "foo" && gpo;
        */},
        res: {
          ie11: false,
          edge14: true,
          chrome57: true,
          firefox2: false,
          firefox49: true,
          opera10_50: false,
          node8: true,
          safari10: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      }
    ]
  },
  {
    name: 'Proxy "ownKeys" handler, duplicate keys for non-extensible targets',
    category: '2018 misc',
    significance: 'tiny',
    spec: 'https://tc39.es/ecma262/#sec-proxy-object-internal-methods-and-internal-slots-ownpropertykeys',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Proxy/handler/ownKeys',
    exec: function () {/*
      var p = new Proxy({}, {
        ownKeys() {
          return ["a", "a"];
        }
      });
      try {
        Object.keys(p);
      } catch (e) {
        return e instanceof TypeError;
      }
      return false;
    */},
    res: {
      ie11: false,
      edge16: false,
      chrome75: true,
      firefox57: true,
      firefox70: true,
      safari13: true,
      duktape2_0: false,
      jerryscript2_3_0: false,
      jerryscript2_4_0: true,
      graalvm19: false,
      graalvm20: true,
      hermes0_7_0: true,
      reactnative0_70_3: true,
      rhino1_7_13: false
    }
  },
  {
    name: 'RegExp "u" flag, case folding',
    category: '2017 misc',
    significance: 'tiny',
    spec: 'https://github.com/tc39/ecma262/pull/525',
    exec: function () {/*
      return "ſ".match(/\w/iu) && !"ſ".match(/\W/iu)
        && "\u212a".match(/\w/iu) && !"\u212a".match(/\W/iu)
        && "\u212a".match(/.\b/iu) && "ſ".match(/.\b/iu)
        && !"\u212a".match(/.\B/iu) && !"ſ".match(/.\B/iu);
    */},
    res: {
      ie11: false,
      firefox2: false,
      firefox54: true,
      opera10_50: false,
      chrome59: true,
      safari10: true,
      safari10_1: true,
      duktape2_0: false,
      jerryscript2_3_0: false,
      jerryscript2_4_0: true,
      graalvm19: true,
      hermes0_7_0: false,
      reactnative0_70_3: false,
      rhino1_7_13: false
    }
  },
  {
    name: 'assignments allowed in for-in head in non-strict mode',
    spec: 'https://tc39.github.io/ecma262/#sec-initializers-in-forin-statement-heads',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for...in#Compatibility_Initializer_expressions_in_strict_mode',
    category: '2017 annex b',
    significance: 'tiny',
    exec: function () {/*
      for (var i = 0 in {}) {}
      return i === 0;
    */},
    res: {
      tr: true,
      babel7corejs3: true,
      ie10: true,
      edge12: true,
      firefox2: true,
      firefox31: true,
      firefox40: false,
      firefox52: true,
      opera10_50: true,
      chrome30: true,
      safari3_1: true,
      safari9: false,
      safari10_1: true,
      node0_12: true,
      android4_0: true,
      ios5_1: true,
      duktape2_0: true,
      nashorn1_8: true,
      nashorn9: true,
      nashorn10: true,
      jerryscript2_3_0: false,
      graalvm19: true,
      hermes0_7_0: true,
      reactnative0_70_3: false,
      rhino1_7_13: true
    }
  },
  {
    name: 'arguments.caller removed',
    category: '2017 misc',
    significance: 'tiny',
    spec: 'https://github.com/tc39/ecma262/pull/689',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/arguments/caller',
    exec: function () {/*
      return (function () {
        'use strict';
        return !Object.getOwnPropertyDescriptor(arguments, 'caller');
      })();
    */},
    res: {
      ie11: false,
      edge16: true,
      firefox2: false,
      firefox53: true,
      opera10_50: false,
      chrome56: true,
      node8: true,
      safari10_1: true,
      duktape2_0: false,
      duktape2_4: true,
      jerryscript2_3_0: false,
      jerryscript2_4_0: true,
      graalvm19: true,
      hermes0_7_0: false,
      reactnative0_70_3: false,
      rhino1_7_13: false
    }
  },
  {
    name: 'object rest/spread properties',
    significance: 'medium',
    category: '2018 features',
    spec: 'https://github.com/tc39/proposal-object-rest-spread',
    subtests: [
      {
        name: 'object rest properties',
        exec: function () {/*
          var { a, ...rest } = { a: 1, b: 2, c: 3 };
          return a === 1 && rest.a === void undefined && rest.b === 2 && rest.c === 3;
        */},
        res: {
          babel6corejs2: true,
          closure: true,
          closure20181028: {
            val: false,
            note_id: 'closure-object-assign',
            note_html: 'Requires native support for <code>Object.assign</code>'
          },
          closure20210906: true,
          typescript2_1corejs2: true,
          jsx: true,
          ie11: false,
          firefox2: false,
          firefox55: true,
          opera10_50: false,
          chrome58: chrome.experimental,
          chrome60: true,
          safari11: false,
          safari11_1: true,
          safaritp: true,
          webkit: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'object spread properties',
        exec: function () {/*
          var spread = { b: 2, c: 3 };
          var O = { a: 1, ...spread };
          return O !== spread && (O.a + O.b + O.c) === 6;
        */},
        res: {
          babel6corejs2: true,
          closure: true,
          closure20190121: {
            val: false,
            note_id: 'closure-object-assign'
          },
          closure20210906: true,
          jsx: true,
          ie11: false,
          firefox2: false,
          firefox55: true,
          opera10_50: false,
          chrome58: chrome.experimental,
          chrome60: true,
          typescript2_1corejs2: true,
          safari11: false,
          safari11_1: true,
          safaritp: true,
          webkit: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      }
    ]
  },
  {
    name: 'Promise.prototype.finally',
    category: '2018 features',
    significance: 'medium',
    spec: 'https://github.com/tc39/proposal-promise-finally',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/finally',
    subtests: [
      {
        name: 'basic support',
        exec: function () {/*
          var p1 = Promise.resolve("foo");
          var p2 = Promise.reject("bar");
          var score = 0;
          function thenFn(result) {
            score += (result === "foo");
            check();
          }
          function catchFn(result) {
            score += (result === "bar");
            check();
          }
          function finallyFn() {
            score += (arguments.length === 0);
            check();
          }
          p1.then(thenFn);
          p1.finally(finallyFn);
          p1.finally(function () {
            // should return a new Promise
            score += p1.finally() !== p1;
            check();
          });
          p2.catch (catchFn);
          p2.finally(finallyFn);
          function check() {
            if (score === 5) asyncTestPassed();
          }
        */},
        res: {
          babel6corejs2: babel.corejs,
          closure: false,
          closure20180402: true,
          typescript1corejs2: typescript.corejs,
          ie11: false,
          edge18: true,
          firefox2: false,
          firefox57: false,
          firefox58: true,
          opera10_50: false,
          chrome61: chrome.promise,
          chrome63: true,
          safari11_1: true,
          safaritp: true,
          webkit: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false,
          rhino1_7_15: true
        }
      },
      {
        name: 'don\'t change resolution value',
        exec: function () {/*
          var score = 0;
          function thenFn(result)  {
            score += (result === "foo");
            check();
          }
          function catchFn(result) {
            score += (result === "bar");
            check();
          }
          function finallyFn() {
            score++;
            check();
            return Promise.resolve("foobar");
          }
          Promise.resolve("foo").finally(finallyFn).then(thenFn);
          Promise.reject("bar").finally(finallyFn).catch(catchFn);
          function check() {
            if (score === 4) asyncTestPassed();
          }
        */},
        res: {
          babel6corejs2: babel.corejs,
          closure: false,
          closure20180402: true,
          typescript1corejs2: typescript.corejs,
          ie11: false,
          edge18: true,
          firefox2: false,
          firefox57: false,
          firefox58: true,
          opera10_50: false,
          chrome61: chrome.promise,
          chrome63: true,
          safari11_1: true,
          safaritp: true,
          webkit: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false,
          rhino1_7_15: true
        }
      },
      {
        name: 'change rejection value',
        exec: function () {/*
          var score = 0;
          Promise
            .reject("foobar")
            .finally(function () {
              return Promise.reject("foo");
            })
            .catch (function (result) {
              score += (result === "foo");
              check();
              return Promise.reject("foobar");
            })
            .finally(function () {
              throw new Error('bar');
            })
            .catch (function (result) {
              score += (result.message === "bar");
              check();
            });
          function check() {
            if (score === 2) asyncTestPassed();
          }
        */},
        res: {
          babel6corejs2: babel.corejs,
          closure: false,
          closure20180402: true,
          typescript1corejs2: typescript.corejs,
          ie11: false,
          edge18: true,
          firefox2: false,
          firefox57: false,
          firefox58: true,
          opera10_50: false,
          safari11_1: true,
          safaritp: true,
          chrome61: chrome.promise,
          chrome63: true,
          webkit: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false,
          rhino1_7_15: true
        }
      }
    ]
  },
  {
    name: 'template literal revision',
    spec: 'https://github.com/tc39/proposal-template-literal-revision',
    category: '2018 misc',
    significance: 'small',
    exec: function () {/*
      function tag(strings, a) {
        return strings[0] === void undefined
          && strings.raw[0] === "\\01\\1\\xg\\xAg\\u0\\u0g\\u00g\\u000g\\u{g\\u{0\\u{110000}"
          && strings[1] === "\0"
          && strings.raw[1] === "\\0"
          && a === 0;
      }
      return tag`\01\1\xg\xAg\u0\u0g\u00g\u000g\u{g\u{0\u{110000}${0}\0`;
    */},
    res: {
      babel7corejs3: true,
      closure: false,
      closure20181008: true,
      closure20200315: false,
      closure20200517: true,
      ie11: false,
      firefox2: false,
      firefox53: true,
      opera10_50: false,
      chrome59: chrome.harmony,
      chrome62: true,
      safari11: true,
      duktape2_0: false,
      jerryscript2_3_0: false,
      graalvm19: true,
      hermes0_7_0: true,
      reactnative0_70_3: true,
      rhino1_7_13: false,
      rhino1_7_14: true,
    }
  },
  {
    name: 's (dotAll) flag for regular expressions',
    spec: 'https://tc39.github.io/ecma262/#sec-get-regexp.prototype.dotAll',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/dotAll',
    category: '2018 features',
    significance: 'small',
    exec: function () {/*
    const regex = /foo.bar/s;
    return regex.test('foo\nbar');
  */},
    res : {
      es6tr: null,
      tr: null,
      babel6corejs2: true,
      closure: false,
      jsx: null,
      typescript1corejs2: null,
      es6shim: null,
      konq4_14: null,
      ie7: null,
      ie10: false,
      firefox1: null,
      firefox2: false,
      firefox77: false,
      firefox78: true,
      opera10_50: false,
      chrome1: null,
      chrome60: chrome.harmony,
      chrome62: true,
      safari11_1: true,
      safaritp: true,
      webkit: true,
      xs6: null,
      jxa: null,
      node0_10: null,
      duktape2_0: false,
      duktape2_2: false,
      jerryscript2_3_0: false,
      jerryscript2_4_0: true,
      android1_5: null,
      ios4: null,
      graalvm19: true,
      hermes0_7_0: true,
      reactnative0_70_3: true,
      rhino1_7_13: false,
      rhino1_7_15: true
    }
  },
  {
    name: 'RegExp named capture groups',
    spec: 'https://github.com/tc39/proposal-regexp-named-groups',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions/Groups_and_Ranges',
    category: '2018 features',
    significance: 'small',
    exec: function () {/*
      var result = /(?<year>\d{4})-(?<month>\d{2})-(?<day>\d{2})/.exec('2016-03-11');
      return result.groups.year === '2016'
        && result.groups.month === '03'
        && result.groups.day === '11'
        && result[0] === '2016-03-11'
        && result[1] === '2016'
        && result[2] === '03'
        && result[3] === '11';
      */},
    res : {
      babel6corejs2: true,
      ie11: false,
      firefox2: false,
      firefox77: false,
      firefox78: true,
      opera10_50: false,
      chrome60: chrome.harmony,
      chrome64: true,
      safari11_1: true,
      safaritp: true,
      duktape2_0: false,
      jerryscript2_3_0: false,
      graalvm19: true,
      hermes0_7_0: false,
      reactnative0_70_3: false,
      rhino1_7_13: false
    }
  },
  {
    name: 'RegExp Lookbehind Assertions',
    spec: 'https://github.com/tc39/proposal-regexp-lookbehind',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions/Assertions',
    category: '2018 features',
    significance: 'small',
    exec: function () {/*
    return /(?<=a)b/.test('ab') && /(?<!a)b/.test('cb') &&
           !/(?<=a)b/.test('b');
  */},
    res : {
      babel7corejs3: false,
      ie11: false,
      firefox2: false,
      firefox77: false,
      firefox78: true,
      opera10_50: false,
      chrome50: chrome.harmony,
      chrome62: true,
      safari13_1: false,
      safari16_4: true,
      duktape2_0: false,
      jerryscript2_3_0: false,
      graalvm19: true,
      hermes0_7_0: true,
      reactnative0_70_3: true,
      rhino1_7_13: false,
      safaritp: true
    }
  },
  {
    name: 'RegExp Unicode Property Escapes',
    category: '2018 features',
    significance: 'small',
    spec: 'https://github.com/tc39/proposal-regexp-unicode-property-escapes',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions/Unicode_Property_Escapes',
    subtests: [
      {
        name: 'basic',
        exec: function () {/*
        const regexGreekSymbol = /\p{Script=Greek}/u;
        return regexGreekSymbol.test('π');
      */},
        res: {
          babel6corejs2: true,
          ie11: false,
          firefox2: false,
          firefox77: false,
          firefox78: true,
          opera10_50: false,
          chrome59: chrome.harmony,
          chrome64: true,
          safari11_1: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'Unicode 11',
        // 2018	June 5
        exec: function () {/*
        return /\p{Extended_Pictographic}/u.test("\xA9") && /\p{Emoji}/u.test("🥰");
      */},
        res: {
          chrome67: false,
          chrome68: true,
          firefox77: false,
          firefox78: true,
          safari14: false,
          safari14_1: true,
          node10_9: false,
          node11_0: true,
          duktape2_0: false,
          ie11: false,
          jerryscript2_3_0: false,
          hermes0_7_0: false,
          rhino1_7_13: false,
        }
      },
      {
        name: 'Unicode 12',
        // 2019	March 5
        exec: function () {/*
        return /\p{Script=Elymaic}/u.test("\u{10fe0}") && /\p{Emoji}/u.test("🥱");
      */},
        res: {
          chrome74: false,
          chrome75: true,
          firefox77: false,
          firefox78: true,
          safari14: false,
          safari14_1: true,
          node12_0: false,
          node12_5: true,
          duktape2_0: false,
          ie11: false,
          jerryscript2_3_0: false,
          hermes0_7_0: false,
          rhino1_7_13: false,
        }
      },
      {
        name: 'Unicode 12.1',
        // 2019	May 7
        exec: function () {/*
        return /\p{Other_Symbol}/u.test("\u32FF");
      */},
        res: {
          chrome74: false,
          chrome75: true,
          firefox77: false,
          firefox78: true,
          safari14: false,
          safari14_1: true,
          node12_0: false,
          node12_5: true,
          duktape2_0: false,
          ie11: false,
          jerryscript2_3_0: false,
          hermes0_7_0: false,
          rhino1_7_13: false,
        }
      },
      {
        name: 'Unicode 13',
        // 2020	March 10
        exec: function () {/*
        return /\p{Script=Chorasmian}/u.test("\u{10fb0}") && /\p{Emoji}/u.test("🥲");
      */},
        res: {
          chrome83: false,
          chrome84: true,
          firefox77: false,
          firefox78: true,
          safari14: false,
          safari14_1: true,
          node13_2: false,
          node14_0: true,
          duktape2_0: false,
          ie11: false,
          jerryscript2_3_0: false,
          hermes0_7_0: false,
          rhino1_7_13: false,
        }
      },
      {
        name: 'Unicode 14',
        // 2021	September 14
        exec: function () {/*
        return /\p{Script=Vithkuqi}/u.test("\u{10570}") && /\p{Emoji}/u.test("🫠");
      */},
        res: {
          ie11: false,
          chrome97: false,
          chrome98: true,
          firefox95: false,
          firefox96: true,
          safari15_3: false,
          safari15_4: true,
          node16_11: false,
          node17_0: false,
          node17_2: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          hermes0_7_0: false,
          rhino1_7_13: false,
        }
      },
      {
        name: 'Unicode 15',
        // 2022	September 13
        exec: function () {/*
        return /\p{Script=Kawi}/u.test("\u{11f00}") && /\p{Emoji}/u.test("🫨");
      */},
        res: {
          ie11: false,
          chrome109: false,
          chrome110: true,
          firefox109: false,
          firefox110: true,
          safari11_1: false,
          safari16_6: false,
          safari17: true,
          safaritp: true,
          node0_10: false,
          node16_11: false,
          node18_3: false,
          node19_0: false,
          node19_2: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          hermes0_7_0: false,
          rhino1_7_13: false,
        }
      },
      {
        name: 'Unicode 15.1',
        // 2023 September 12
        exec: function () {/*
        return /\p{Unified_Ideograph}/u.test("\u{2ebf0}");
      */},
        res: {
          ie11: false,
          chrome117: false,
          chrome118: false,
          chrome124: false,
          chrome125: true,
          node20_0: false,
          node21_0: false,
          node22_0: true,
          firefox2: false,
          firefox115: false,
          firefox117: false,
          firefox118: false,
          firefox133: false,
          firefox134: true,
          safari11_1: false,
          safaritp: false,
          safari17: false,
          safari18: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          hermes0_7_0: false,
          rhino1_7_13: false,
        }
      },
      {
        name: 'Unicode 16.0',
        // 2024 September 10
        exec: function () {/*
          return /\p{Script=Todhri}/u.test("\u{105c0}") && /\p{Emoji}/u.test("🫩");
        */},
        res: {
          chrome128: false,
          node22_0: false,
          firefox115: false,
          firefox130: false,
          firefox133: false,
          firefox134: true,
          safari17_6: false,
          safari18: false,
        }
      }
    ]
  },
  {
    name: 'Asynchronous Iterators',
    category: '2018 features',
    significance: 'medium',
    spec: 'https://github.com/tc39/proposal-async-iteration',
    subtests: [
      {
        name: 'async generators',
        exec: function () {/*
          async function*generator() {
            yield 42;
          }

          var iterator = generator();
          iterator.next().then(function (step) {
            if(iterator[Symbol.asyncIterator]() === iterator && step.done === false && step.value === 42)asyncTestPassed();
          });
        */},
        res: {
          babel6corejs2: true,
          closure: false,
          closure20180805: true,
          chrome62: chrome.harmony,
          chrome63: true,
          typescript2_3corejs2: true,
          ie11: false,
          firefox2: false,
          firefox55: firefox.nightly,
          firefox57: true,
          opera10_50: false,
          safari12: true,
          webkit: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'for-await-of loops',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for-await...of',
        exec: function () {/*
          var asyncIterable = {};
          asyncIterable[Symbol.asyncIterator] = function () {
            var i = 0;
            return {
              next: function () {
                switch(++i) {
                  case 1: return Promise.resolve({done: false, value: 'a'});
                  case 2: return Promise.resolve({done: false, value: 'b'});
                } return Promise.resolve({done: true});
              }
            };
          };

          (async function () {
            var result = '';
            for await(var value of asyncIterable)result += value;
            if(result === 'ab')asyncTestPassed();
          })();
        */},
        res: {
          babel6corejs2: true,
          closure: false,
          closure20180910: true,
          chrome62: chrome.harmony,
          chrome63: true,
          typescript2_3corejs2: true,
          ie11: false,
          firefox2: false,
          firefox55: firefox.nightly,
          firefox57: true,
          opera10_50: false,
          safari12: true,
          webkit: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      }
    ]
  },
  {
    name: 'optional catch binding',
    category: '2019 misc',
    significance: 'small',
    spec: 'https://github.com/tc39/proposal-optional-catch-binding',
    subtests: [
      {
        name: 'basic',
        exec: function () {/*
          try {
            throw new Error();
          }
          catch {
            return true;
          }
          return false;
        */},
        res: {
          babel7corejs2: true,
          closure: false,
          closure20190215: true,
          typescript2_5corejs2: true,
          ie11: false,
          firefox2: false,
          firefox57: false,
          firefox58: true,
          opera10_50: false,
          chrome65: chrome.harmony,
          chrome66: true,
          safari11_1: true,
          safaritp: true,
          webkit: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false,
          rhino1_7_15: true
        }
      },
      {
        name: 'await',
        exec: function () {/*
          (async function () {
            try {
              await Promise.reject();
            }
            catch {
              asyncTestPassed();
            }
          })();
        */},
        res: {
          babel7corejs2: true,
          closure: false,
          closure20190215: true,
          typescript2_5corejs2: true,
          ie11: false,
          firefox2: false,
          firefox57: false,
          firefox58: true,
          opera10_50: false,
          chrome65: chrome.harmony,
          chrome66: true,
          safari11_1: true,
          safaritp: true,
          webkit: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'yield',
        exec: function () {/*
          function *foo() {
            try {
              yield;
            }
            catch {
              return true;
            }
          }

          var it = foo();
          it.next();
          return it.throw().value;
        */},
        res: {
          babel7corejs2: true,
          closure: false,
          closure20190215: true,
          typescript2_5corejs2: true,
          ie11: false,
          firefox2: false,
          firefox57: false,
          firefox58: true,
          chrome65: chrome.harmony,
          chrome66: true,
          safari11_1: true,
          safaritp: true,
          webkit: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm20: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false,
          rhino1_7_15: true
        }
      }
    ]
  },
  {
    name: 'Symbol.prototype.description',
    spec: 'https://github.com/tc39/proposal-Symbol-description',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/description',
    category: '2019 features',
    significance: 'small',
    subtests: [
      {
        name: 'basic',
        exec: function () {/*
          return Symbol('foo').description === 'foo';
        */},
        res : {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          closure: false,
          closure20190301: true,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox10: false,
          firefox45: false,
          firefox63: true,
          chrome67: false,
          chrome69: chrome.harmony,
          chrome70: true,
          safari11: false,
          safari12: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'empty description',
        exec: function () {/*
          return Symbol('').description === '';
        */},
        res : {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          closure: false,
          closure20190301: true,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox10: false,
          firefox45: false,
          firefox63: true,
          chrome67: false,
          chrome69: chrome.harmony,
          chrome70: true,
          safari11: false,
          safari12: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'undefined description',
        exec: function () {/*
          return Symbol.prototype.hasOwnProperty('description')
            && Symbol().description === void undefined;
        */},
        res : {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox10: false,
          firefox45: false,
          firefox63: true,
          chrome67: false,
          chrome69: chrome.harmony,
          chrome70: true,
          safari11: false,
          safari12: false,
          safari12_1: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      }
    ]
  },
  {
    name: 'Function.prototype.toString revision',
    category: '2019 misc',
    significance: 'small',
    spec: 'https://github.com/tc39/Function-prototype-toString-revision',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/toString',
    subtests: [{
      name: 'functions created with the Function constructor',
      exec: function () {/*
        var fn = function ('a', ' /\x2A a \x2A/ b, c /\x2A b \x2A/ //', '/\x2A c \x2A/ ; /\x2A d \x2A/ //');
        var str = 'function anonymous(a, /\x2A a \x2A/ b, c /\x2A b \x2A/ //\n) {\n/\x2A c \x2A/ ; /\x2A d \x2A/ //\n}';
        return fn + '' === str;
    */},
      res: {
        ie11: false,
        firefox2: false,
        firefox54: true,
        opera10_50: false,
        chrome59: chrome.harmony,
        chrome66: true,
        duktape2_0: false,
        jerryscript2_3_0: false,
        graalvm19: true,
        hermes0_7_0: false,
        reactnative0_70_3: false,
        rhino1_7_13: false,
        safari18: true,
      }
    }, {
      name: 'arrows',
      exec: function () {/*
        var str = 'a => b';
        return eval('(' + str + ')') + '' === str;
    */},
      res: {
        node4: true,
        firefox2: false,
        firefox51: true,
        opera10_50: false,
        chrome50: true,
        safari10: true,
        ie11: false,
        edge13: true,
        duktape2_0: false,
        nashorn1_8: true,
        nashorn9: true,
        nashorn10: true,
        jerryscript2_3_0: false,
        graalvm19: true,
        hermes0_7_0: false,
        reactnative0_70_3: false,
        rhino1_7_13: false
      }
    }, {
      name: '[native code]',
      exec: function () {/*
        const NATIVE_EVAL_RE = /\bfunction\b[\s\S]*\beval\b[\s\S]*\([\s\S]*\)[\s\S]*\{[\s\S]*\[[\s\S]*\bnative\b[\s\S]+\bcode\b[\s\S]*\][\s\S]*\}/;
        return NATIVE_EVAL_RE.test(eval + '');
    */},
      res: {
        node4: true,
        firefox2: false,
        firefox10: true,
        firefox45: true,
        opera10_50: true,
        chrome50: true,
        safari3_1: true,
        ie11: true,
        edge13: true,
        duktape2_0: true,
        nashorn9: true,
        nashorn10: true,
        jerryscript2_3_0: false,
        graalvm19: true,
        hermes0_7_0: true,
        reactnative0_70_3: true,
        rhino1_7_13: true
      }
    }, {
      name: 'class expression with implicit constructor',
      exec: function () {/*
        var str = 'class A {}';
        return eval('(' + str + ')') + '' === str;
    */},
      res: {
        node4: true,
        firefox2: false,
        firefox55: true,
        opera10_50: false,
        chrome50: true,
        safari10: true,
        ie11: false,
        edge14: true,
        duktape2_0: false,
        jerryscript2_3_0: false,
        graalvm19: true,
        hermes0_7_0: false,
        reactnative0_70_3: false,
        rhino1_7_13: false
      }
    }, {
      name: 'class expression with explicit constructor',
      exec: function () {/*
        var str = 'class /\x2A a \x2A/ A /\x2A b \x2A/ extends /\x2A c \x2A/ function B() {} /\x2A d \x2A/ { /\x2A e \x2A/ constructor /\x2A f \x2A/ ( /\x2A g \x2A/ ) /\x2A h \x2A/ { /\x2A i \x2A/ ; /\x2A j \x2A/ } /\x2A k \x2A/ m /\x2A l \x2A/ ( /\x2A m \x2A/ ) /\x2A n \x2A/ { /\x2A o \x2A/ } /\x2A p \x2A/ }';
        return eval('(/\x2A before \x2A/' + str + '/\x2A after \x2A/)') + '' === str;
    */},
      res: {
        node4: true,
        firefox2: false,
        firefox55: true,
        opera10_50: false,
        chrome50: true,
        safari10: true,
        ie11: false,
        edge14: true,
        duktape2_0: false,
        jerryscript2_3_0: false,
        graalvm19: true,
        hermes0_7_0: false,
        reactnative0_70_3: false,
        rhino1_7_13: false
      }
    }, {
      name: 'unicode escape sequences in identifiers',
      exec: function () {/*
        var str = 'function \\u0061(\\u{62}, \\u0063) { \\u0062 = \\u{00063}; return b; }';
        return eval('(/\x2A before \x2A/' + str + '/\x2A after \x2A/)') + '' === str;
    */},
      res: {
        ie11: false,
        firefox2: false,
        firefox54: true,
        opera10_50: false,
        chrome59: chrome.harmony,
        chrome66: true,
        safari17: true,
        duktape2_0: false,
        jerryscript2_3_0: false,
        graalvm19: true,
        hermes0_7_0: false,
        reactnative0_70_3: false,
        rhino1_7_13: false
      }
    }, {
      name: 'methods and computed property names',
      exec: function () {/*
        var str = '[ /\x2A a \x2A/ "f" /\x2A b \x2A/ ] /\x2A c \x2A/ ( /\x2A d \x2A/ ) /\x2A e \x2A/ { /\x2A f \x2A/ }';
        return eval('({ /\x2A before \x2A/' + str + '/\x2A after \x2A/ }.f)') + '' === str;
    */},
      res: {
        ie11: false,
        firefox2: false,
        firefox54: true,
        opera10_50: false,
        chrome59: chrome.harmony,
        chrome66: true,
        safari17: true,
        duktape2_0: false,
        nashorn9: true,
        nashorn10: true,
        jerryscript2_3_0: false,
        graalvm19: true,
        hermes0_7_0: false,
        reactnative0_70_3: false,
        rhino1_7_13: false
      }
    }]
  },
  {
    name: 'JSON superset',
    spec: 'https://github.com/tc39/proposal-json-superset',
    category: '2019 misc',
    significance: 'small',
    subtests: [
      {
        name: 'LINE SEPARATOR can appear in string literals',
        exec: function () {/*
          return eval("'\u2028'") === "\u2028";
        */},
        res : {
          closure: false,
          closure20190215: true,
          babel7corejs2: true,
          ie11: false,
          firefox2: false,
          firefox61: false,
          firefox62: true,
          chrome65: false,
          chrome66: true,
          safari11: false,
          safari12: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false,
          rhino1_7_14: true,
        }
      },
      {
        name: 'PARAGRAPH SEPARATOR can appear in string literals',
        exec: function () {/*
          return eval("'\u2029'") === "\u2029";
        */},
        res : {
          closure: false,
          closure20190215: true,
          babel7corejs2: true,
          ie11: false,
          firefox2: false,
          firefox61: false,
          firefox62: true,
          chrome65: false,
          chrome66: true,
          safari11: false,
          safari12: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false,
          rhino1_7_14: true,
        }
      }
    ]
  },
  {
    name: 'Object.fromEntries',
    significance: 'small',
    spec: 'https://github.com/tc39/proposal-object-from-entries',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/fromEntries',
    category: '2019 features',
    exec: function () {/*
    var object = Object.fromEntries(new Map([['foo', 42], ['bar', 23]]));
    return object.foo === 42 && object.bar === 23;
  */},
    res: {
      babel6corejs2: false,
      babel7corejs3: babel.corejs,
      closure: false,
      closure20190325: true,
      typescript1corejs2: typescript.fallthrough,
      typescript3_2corejs3: typescript.corejs,
      ie11: false,
      firefox10: false,
      firefox52: false,
      firefox62: false,
      firefox63: true,
      safari12_1: true,
      safaritp: true,
      duktape2_0: false,
      jerryscript2_3_0: false,
      jerryscript2_4_0: true,
      graalvm19: true,
      chrome73: true,
      chrome74: true,
      hermes0_7_0: true,
      reactnative0_70_3: true,
      rhino1_7_13: false,
      rhino1_7_14: true,
    }
  },
  {
    name: 'Well-formed JSON.stringify',
    spec: 'https://github.com/tc39/proposal-well-formed-stringify',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify#Well-formed_JSON.stringify()',
    category: '2019 misc',
    significance: 'small',
    exec: function () {/*
    return JSON.stringify('\uDF06\uD834') === "\"\\udf06\\ud834\""
      && JSON.stringify('\uDEAD') === "\"\\udead\"";
  */},
    res: {
      babel6corejs2: false,
      babel7corejs3: babel.corejs,
      typescript1corejs2: typescript.fallthrough,
      typescript3_2corejs3: typescript.corejs,
      ie11: false,
      edge16: false,
      firefox10: false,
      firefox52: false,
      firefox63: false,
      firefox64: true,
      chrome70: false,
      chrome71: false,
      chrome72: true,
      safari1: false,
      safari12_1: true,
      safaritp: true,
      duktape2_0: false,
      jerryscript2_3_0: false,
      jerryscript2_4_0: true,
      graalvm19: true,
      hermes0_7_0: false,
      reactnative0_70_3: false,
      rhino1_7_13: false
    }
  },
  {
    name: 'string trimming',
    category: '2019 features',
    significance: 'small',
    spec: 'https://github.com/tc39/proposal-string-left-right-trim',
    subtests: [
      {
        name: 'String.prototype.trimLeft',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/TrimLeft',
        exec: function () {/*
        return ' \t \n abc   \t\n'.trimLeft() === 'abc   \t\n';
      */},
        res: {
          babel6corejs2: babel.corejs,
          closure: false,
          closure20190709: true,
          typescript1corejs2: typescript.corejs,
          ie11: false,
          edge12: true,
          firefox2: false,
          firefox3_5: true,
          firefox3_6: true,
          firefox4: true,
          chrome7: true,
          opera10_10: false,
          konq4_4: false,
          konq4_9: true,
          besen: false,
          phantom1_9: true,
          node0_12: true,
          safari3: false,
          safari4: true,
          safari12: true,
          webkit: true,
          es7shim: true,
          android4_0: true,
          ios5_1: true,
          duktape2_0: false,
          nashorn1_8: true,
          nashorn9: true,
          nashorn10: true,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: true
        }
      },
      {
        name: 'String.prototype.trimRight',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/TrimRight',
        exec: function () {/*
        return ' \t \n abc   \t\n'.trimRight() === ' \t \n abc';
      */},
        res: {
          babel6corejs2: babel.corejs,
          closure: false,
          closure20190709: true,
          typescript1corejs2: typescript.corejs,
          ie11: false,
          edge12: true,
          firefox2: false,
          firefox3_5: true,
          firefox3_6: true,
          firefox4: true,
          chrome7: true,
          opera10_10: false,
          konq4_4: false,
          konq4_9: true,
          besen: false,
          phantom1_9: true,
          node0_12: true,
          safari3: false,
          safari4: true,
          safari12: true,
          webkit: true,
          es7shim: true,
          android4_0: true,
          ios5_1: true,
          duktape2_0: false,
          nashorn1_8: true,
          nashorn9: true,
          nashorn10: true,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: true
        }
      },
      {
        name: 'String.prototype.trimStart',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/trimStart',
        exec: function () {/*
        return ' \t \n abc   \t\n'.trimStart() === 'abc   \t\n';
      */},
        res: {
          babel6corejs2: babel.corejs,
          closure: false,
          closure20190325: {
            val: false,
            note_id: 'closure-string-trimstart',
            note_html: 'Requires native support for String.prototype.trimLeft.'
          },
          closure20190709: true,
          typescript1corejs2: typescript.corejs,
          ie11: false,
          firefox2: false,
          firefox59: false,
          firefox60: firefox.nightly,
          firefox61: true,
          chrome66: true,
          opera10_50: false,
          safari12: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: true
        }
      },
      {
        name: 'String.prototype.trimEnd',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/trimEnd',
        exec: function () {/*
        return ' \t \n abc   \t\n'.trimEnd() === ' \t \n abc';
      */},
        res: {
          babel6corejs2: babel.corejs,
          closure: false,
          closure20190325: {
            val: false,
            note_id: 'closure-string-trimend',
            note_html: 'Requires native support for String.prototype.trimRight.'
          },
          closure20190709: true,
          typescript1corejs2: typescript.corejs,
          ie11: false,
          firefox2: false,
          firefox59: false,
          firefox60: firefox.nightly,
          firefox61: true,
          chrome66: true,
          opera10_50: false,
          safari12: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: true
        }
      }
    ]
  },
  {
    name: 'Array.prototype.{flat, flatMap}',
    category: '2019 features',
    significance: 'medium',
    spec: 'https://tc39.github.io/proposal-flatMap/',
    links: [
      {
        note_id: 'flatten-compat-issue',
        note_html: 'Name of <code>Array.prototype.flatten()</code> changed to <code>Array.prototype.flat()</code> due to <a href="https://github.com/tc39/proposal-flatMap/pull/56">web compatibility issues.</a>'
      }
    ],
    subtests: [
      {
        name: 'Array.prototype.flat',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/flat',
        exec: function () {/*
        return [1, [2, 3], [4, [5, 6]]].flat().join('') === '12345,6';
      */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          closure: false,
          closure20190301: true,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox2: false,
          firefox58: false,
          firefox59: {
            val: false,
            note_id: 'ffox-flatten',
            note_html: 'Older Firefox Nightly builds support only the obsolete draft function name <code>Array.prototype.flatten()</code>.'
          },
          firefox62: true,
          chrome69: true,
          opera10_50: false,
          safari12: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false,
          rhino1_7_15: true
        }
      },
      {
        name: 'Array.prototype.flatMap',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/flatMap',
        exec: function () {/*
        return [{a: 1, b: 2}, {a: 3, b: 4}].flatMap(function (it) {
          return [it.a, it.b];
        }).join('') === '1234';
      */},
        res: {
          babel6corejs2: babel.corejs,
          closure: false,
          closure20190301: true,
          typescript1corejs2: typescript.corejs,
          ie11: false,
          firefox2: false,
          firefox58: false,
          firefox59: firefox.nightly,
          firefox62: true,
          chrome69: true,
          opera10_50: false,
          safari12: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false,
          rhino1_7_15: true
        }
      },
      {
        name: 'flat and flatMap in Array.prototype[@@unscopables]',
        exec: function () {/*
        return Array.prototype[Symbol.unscopables].flat
          && Array.prototype[Symbol.unscopables].flatMap;
      */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox2: false,
          firefox58: false,
          firefox59: false,
          firefox62: false,
          firefox67: true,
          chrome69: false,
          chrome73: true,
          chrome74: true,
          opera10_50: false,
          safari12: false,
          safari13: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      }
    ]
  },
  {
    name: 'String.prototype.matchAll',
    category: '2020 features',
    significance: 'small',
    spec: 'https://github.com/tc39/String.prototype.matchAll',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/matchAll',
    subtests: [
      {
        name: 'basic functionality',
        exec: function () {/*
          var iterator = '11a2bb'.matchAll(/(\d)(\D)/g);
          if(iterator[Symbol.iterator]() !== iterator)return false;
          var a = '', b = '', c = '', step;
          while(!(step = iterator.next()).done) {
            a += step.value[0];
            b += step.value[1];
            c += step.value[2];
          }
          return a === '1a2b'
            && b === '12'
            && c === 'ab';
        */},
        res: {
          babel6corejs2: babel.corejs,
          closure: false,
          closure20200101: true,
          typescript1corejs2: typescript.corejs,
          ie11: false,
          firefox2: false,
          firefox65: false,
          firefox66: firefox.nightly,
          firefox67: true,
          chrome67: false,
          chrome68: chrome.harmony,
          chrome73: true,
          chrome74: true,
          opera10_50: false,
          safari13: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          graalvm20: graalvm.es2020flag,
          graalvm20_1: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'throws on non-global regex',
        exec: function () {/*
          if (typeof String.prototype.matchAll !== 'function') return false;
          try {
            '11a2bb'.matchAll(/(\d)(\D)/);
          } catch (e) {
            return true;
          }
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          closure: false,
          closure20200101: true,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox2: false,
          firefox60: false,
          firefox72: false,
          firefox73: true,
          chrome67: false,
          chrome68: false,
          chrome73: false,
          chrome74: false,
          chrome80: true,
          opera10_50: false,
          safari13: false,
          safari13_1: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: false,
          graalvm20: graalvm.es2020flag,
          graalvm20_1: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      }
    ]
  },
  {
    name: 'BigInt',
    category: '2020 features',
    significance: 'medium',
    spec: 'https://github.com/tc39/proposal-bigint',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt',
    subtests: [
      {
        name: 'basic functionality',
        exec: function () {/*
        return (1n + 2n) === 3n;
      */},
        res: {
          ie11: false,
          firefox10: false,
          firefox45: false,
          firefox66: false,
          firefox67: firefox.bigint,
          firefox68: true,
          chrome67: true,
          safari14: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false,
          rhino1_7_14: true,
        }
      },
      {
        name: 'constructor',
        exec: function () {/*
        return BigInt("3") === 3n;
      */},
        res: {
          ie11: false,
          firefox10: false,
          firefox45: false,
          firefox66: false,
          firefox67: firefox.bigint,
          firefox68: true,
          chrome67: true,
          safari14: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false,
          rhino1_7_14: true,
        }
      },
      {
        name: 'BigInt.asUintN',
        exec: function () {/*
        return typeof BigInt.asUintN === 'function';
      */},
        res: {
          ie11: false,
          firefox10: false,
          firefox45: false,
          firefox66: false,
          firefox67: firefox.bigint,
          firefox68: true,
          chrome67: true,
          safari14: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false,
          rhino1_7_14: true,
        }
      },
      {
        name: 'BigInt.asIntN',
        exec: function () {/*
        return typeof BigInt.asIntN === 'function';
      */},
        res: {
          ie11: false,
          firefox10: false,
          firefox45: false,
          firefox66: false,
          firefox67: firefox.bigint,
          firefox68: true,
          chrome67: true,
          safari14: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false,
          rhino1_7_14: true,
        }
      },
      {
        name: 'BigInt64Array',
        exec: function () {/*
        var buffer = new ArrayBuffer(64);
        var view = new BigInt64Array(buffer);
        view[0] = 0x8000000000000000n;
        return view[0] === -0x8000000000000000n;
      */},
        res: {
          ie11: false,
          firefox10: false,
          firefox45: false,
          firefox67: false,
          firefox68: true,
          chrome67: true,
          safari15: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'BigUint64Array',
        exec: function () {/*
        var buffer = new ArrayBuffer(64);
        var view = new BigUint64Array(buffer);
        view[0] = 0x10000000000000000n;
        return view[0] === 0n;
      */},
        res: {
          ie11: false,
          firefox10: false,
          firefox45: false,
          firefox67: false,
          firefox68: true,
          chrome67: true,
          safari15: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'DataView.prototype.getBigInt64',
        exec: function () {/*
        var buffer = new ArrayBuffer(64);
        var view = new DataView(buffer);
        view.setBigInt64(0, 1n);
        return view.getBigInt64(0) === 1n;
      */},
        res: {
          ie11: false,
          firefox10: false,
          firefox45: false,
          firefox66: false,
          firefox67: firefox.bigint,
          firefox68: true,
          chrome67: true,
          safari15: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'DataView.prototype.getBigUint64',
        exec: function () {/*
        var buffer = new ArrayBuffer(64);
        var view = new DataView(buffer);
        view.setBigUint64(0, 1n);
        return view.getBigUint64(0) === 1n;
      */},
        res: {
          ie11: false,
          firefox10: false,
          firefox45: false,
          firefox66: false,
          firefox67: firefox.bigint,
          firefox68: true,
          chrome67: true,
          safari15: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          jerryscript2_4_0: true,
          graalvm19: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      }
    ]
  },
  {
    name: 'Promise.allSettled',
    category: '2020 features',
    significance: 'small',
    spec: 'https://github.com/tc39/proposal-promise-allSettled',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/allSettled',
    exec: function () {/*
      Promise.allSettled([
        Promise.resolve(1),
        Promise.reject(2),
        Promise.resolve(3)
      ]).then(it => {
        if (
          it.length === 3 &&
          it[0].status === 'fulfilled' && it[0].value === 1 &&
          it[1].status === 'rejected' && it[1].reason === 2 &&
          it[2].status === 'fulfilled' && it[2].value === 3
        ) asyncTestPassed();
      });
    */},
    res: {
      babel6corejs2: false,
      babel7corejs3: babel.corejs,
      closure: false,
      closure20191027: true,
      typescript1corejs2: typescript.fallthrough,
      typescript3_2corejs3: typescript.corejs,
      ie11: false,
      firefox10: false,
      firefox68: firefox.nightly,
      firefox71: true,
      chrome76: true,
      safari13: true,
      duktape2_0: false,
      jerryscript2_3_0: false,
      graalvm19: false,
      graalvm20: graalvm.es2020flag,
      graalvm20_1: true,
      hermes0_7_0: false,
      reactnative0_70_3: false,
      rhino1_7_13: false
    }
  },
  {
    name: 'globalThis',
    category: '2020 features',
    significance: 'small',
    spec: 'https://github.com/tc39/proposal-global',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/globalThis',
    subtests: [{
      name: '"globalThis" global property is global object',
      exec: function () {/*
      var actualGlobal = Function ('return this')();
      actualGlobal.__system_global_test__ = 42;
      return typeof globalThis === 'object' && globalThis && globalThis === actualGlobal && !globalThis.lacksGlobalThis && globalThis.__system_global_test__ === 42;
    */},
      res: {
        babel6corejs2: false,
        babel7corejs3: babel.corejs,
        closure: false,
        closure20200101: true,
        typescript1corejs2: typescript.fallthrough,
        typescript3_2corejs3: typescript.corejs,
        ie11: false,
        firefox2: false,
        firefox53: false,
        firefox65: true,
        chrome70: chrome.experimental,
        chrome71: true,
        opera10_50: false,
        safari10_1: false,
        safari12_1: true,
        safaritp: true,
        node0_10: false,
        node0_12: false,
        node4: false,
        node6: false,
        node6_5: false,
        node7: false,
        node7_6: false,
        node8: false,
        node8_3: false,
        node8_7: false,
        duktape2_0: false,
        duktape2_5: true,
        jerryscript2_3_0: false,
        jerryscript2_4_0: true,
        graalvm19: true,
        hermes0_7_0: true,
        reactnative0_70_3: true,
        rhino1_7_13: false,
        rhino1_7_14: true,
      }
    }, {
      name: '"globalThis" global property has correct property descriptor',
      exec: function () {/*
      var actualGlobal = Function ('return this')();
      if (typeof globalThis !== 'object') { return false; }
      if (!('globalThis' in actualGlobal)) { return false; }
      if (Object.prototype.propertyIsEnumerable.call(actualGlobal, 'globalThis')) { return false; }

      var descriptor = Object.getOwnPropertyDescriptor(actualGlobal, 'globalThis');
      return descriptor.value === actualGlobal && !descriptor.enumerable && descriptor.configurable && descriptor.writable;
    */},
      res: {
        babel6corejs2: false,
        babel7corejs3: babel.corejs,
        closure: false,
        closure20200101: true,
        typescript1corejs2: typescript.fallthrough,
        typescript3_2corejs3: typescript.corejs,
        ie11: false,
        firefox2: false,
        firefox53: false,
        firefox65: true,
        chrome70: chrome.experimental,
        chrome71: true,
        opera10_50: false,
        safari10_1: false,
        safari12_1: true,
        safaritp: true,
        node0_10: false,
        node0_12: false,
        node4: false,
        node6: false,
        node6_5: false,
        node7: false,
        node7_6: false,
        node8: false,
        node8_3: false,
        node8_7: false,
        duktape2_0: false,
        duktape2_5: true,
        jerryscript2_3_0: false,
        jerryscript2_4_0: true,
        graalvm19: true,
        hermes0_7_0: true,
        reactnative0_70_3: true,
        rhino1_7_13: false,
        rhino1_7_14: true,
      }
    }]
  },
  {
    name: 'optional chaining operator (?.)',
    spec: 'https://github.com/tc39/proposal-optional-chaining',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Optional_chaining',
    category: '2020 features',
    significance: 'medium',
    subtests: [
      {
        name: 'optional property access',
        exec: function () {/*
          var foo = { baz: 42 };
          var bar = null;
          return foo?.baz === 42 && bar?.baz === void undefined;
        */},
        res : {
          babel7corejs2: true,
          closure: false,
          closure20200927: true,
          typescript3_7corejs3: true,
          ie11: false,
          firefox10: false,
          firefox52: false,
          firefox73: false,
          firefox74: true,
          chrome77: false,
          chrome78: {val: 'flagged', note_id: "chrome-optional-chaining", note_html: "The feature has to be enabled via <code>--js-flags=\"--harmony-optional-chaining\"</code> flag"},
          chrome80: true,
          safari13_1: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: false,
          graalvm20: graalvm.es2020flag,
          graalvm20_1: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'optional bracket access',
        exec: function () {/*
          var foo = { baz: 42 };
          var bar = null;
          return foo?.['baz'] === 42 && bar?.['baz'] === void undefined;
        */},
        res : {
          babel7corejs2: true,
          closure: false,
          closure20200927: true,
          typescript3_7corejs3: true,
          ie11: false,
          firefox10: false,
          firefox52: false,
          firefox73: false,
          firefox74: true,
          chrome77: false,
          chrome78: {val: 'flagged', note_id: "chrome-optional-chaining"},
          chrome80: true,
          safari13_1: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: false,
          graalvm20: graalvm.es2020flag,
          graalvm20_1: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'optional method call',
        exec: function () {/*
          var foo = { baz: function () { return this.value; }, value: 42 };
          var bar = null;
          return foo?.baz() === 42 && bar?.baz() === void undefined;
        */},
        res : {
          babel7corejs2: true,
          closure: false,
          closure20200927: true,
          typescript3_7corejs3: true,
          ie11: false,
          firefox10: false,
          firefox52: false,
          firefox73: false,
          firefox74: true,
          chrome77: false,
          chrome78: {val: 'flagged', note_id: "chrome-optional-chaining"},
          chrome80: true,
          safari13_1: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: false,
          graalvm20: graalvm.es2020flag,
          graalvm20_1: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'optional function call',
        exec: function () {/*
          var foo = { baz: function () { return 42; } };
          var bar = {};
          function baz() { return 42; };
          var n;
          return foo.baz?.() === 42 && bar.baz?.() === void undefined && baz?.() === 42 && n?.() === void undefined;
        */},
        res : {
          babel7corejs2: true,
          closure: false,
          closure20200927: true,
          typescript3_7corejs3: true,
          ie11: false,
          firefox10: false,
          firefox52: false,
          firefox73: false,
          firefox74: true,
          chrome77: false,
          chrome78: {val: 'flagged', note_id: "chrome-optional-chaining"},
          chrome80: true,
          safari13_1: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: false,
          graalvm20: graalvm.es2020flag,
          graalvm20_1: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'spread parameters after optional chaining',
        exec: function () {/*
          var fn = null;
          var n = null;
          var o = {};

          return fn?.(...[], 1) === void undefined && fn?.(...[], ...[]) === void undefined && o.method?.(...[], 1) === void undefined && n?.method(...[], 1) === void undefined;
        */},
        res : {
          babel7corejs3: true,
          closure: false,
          closure20200927: true,
          ie11: false,
          firefox10: false,
          firefox52: false,
          firefox73: false,
          firefox74: true,
          chrome77: false,
          chrome80: false,
          chrome89: false,
          chrome90: false,
          chrome91: true,
          safari13_1: true,
          safaritp: true,
          duktape2_0: false,
          graalvm21_3_3: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      }
    ]
  },
  {
    name: 'nullish coalescing operator (??)',
    spec: 'https://github.com/tc39/proposal-nullish-coalescing',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Nullish_coalescing_operator',
    category: '2020 features',
    significance: 'small',
    exec: function () {/*
      return (null ?? 42) === 42 &&
        (undefined ?? 42) === 42 &&
        (false ?? 42) === false &&
        ('' ?? 42) === '' &&
        (0 ?? 42) === 0 &&
        isNaN(NaN ?? 42);
    */},
    res : {
      babel7corejs2: true,
      closure: false,
      closure20200315: true,
      typescript3_7corejs3: true,
      ie11: false,
      firefox10: false,
      firefox52: false,
      firefox72: true,
      chrome77: false,
      chrome78: {val: 'flagged', note_id: "chrome-nullish", note_html: "The feature has to be enabled via <code>--js-flags=\"--harmony-nullish\"</code> flag"},
      chrome80: true,
      safari13_1: true,
      safaritp: true,
      duktape2_0: false,
      jerryscript2_3_0: false,
      jerryscript2_4_0: true,
      graalvm19: false,
      graalvm20: graalvm.es2020flag,
      graalvm20_1: true,
      hermes0_7_0: true,
      reactnative0_70_3: true,
      rhino1_7_13: false
    }
  },
  {
    name: 'String.prototype.replaceAll',
    significance: 'small',
    spec: 'https://github.com/tc39/proposal-string-replace-all',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replaceAll',
    category: '2021 features',
    exec: function () {/*
      return 'q=query+string+parameters'.replaceAll('+', ' ') === 'q=query string parameters';
    */},
    res: {
      babel6corejs2: false,
      babel7corejs3: babel.corejs,
      closure: false,
      closure20210808: true,
      typescript1corejs2: typescript.fallthrough,
      typescript3_2corejs3: typescript.corejs,
      ie11: false,
      firefox10: false,
      firefox52: false,
      firefox71: false,
      firefox72: firefox.nightly,
      firefox77: true,
      chrome77: false,
      chrome80: chrome.stringPrototypeReplaceAll,
      chrome85: true,
      safari13_1: true,
      safaritp: true,
      duktape2_0: false,
      jerryscript2_3_0: false,
      jerryscript2_4_0: true,
      graalvm19: false,
      graalvm20: graalvm.es2020flag,
      graalvm20_1: graalvm.es2021flag,
      graalvm21: true,
      ios13_4: true,
      hermes0_7_0: true,
      reactnative0_70_3: true,
      rhino1_7_13: false,
      rhino1_7_15: true
    }
  },
  {
    name: 'Promise.any',
    category: '2021 features',
    significance: 'small',
    spec: 'https://github.com/tc39/proposal-promise-any',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/any',
    subtests: [
      {
        name: 'fulfillment',
        exec: function () {/*
          Promise.any([
            Promise.reject(1),
            Promise.resolve(2),
            Promise.resolve(3)
          ]).then(it => {
            if (it === 2) asyncTestPassed();
          });
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          closure: false,
          closure20210808: true,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox10: false,
          firefox60: false,
          firefox72: firefox.nightly,
          firefox79: true,
          chrome77: false,
          chrome84: {val: 'flagged', note_id: "chrome-promise-any", note_html: "Available behind the <a href='https://bugs.chromium.org/p/v8/issues/detail?id=9808'><code>--js-flags=\"--harmony-promise-any\"</code></a> flag in V8."},
          chrome85: true,
          safari14: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm20_3: graalvm.es2021flag,
          graalvm21: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'AggregateError',
        exec: function () {/*
          Promise.any([
            Promise.reject(1),
            Promise.reject(2),
            Promise.reject(3)
          ]).catch (error => {
            if (error instanceof AggregateError && error.errors.length === 3) asyncTestPassed();
          });
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          closure: false,
          closure20210808: true,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox10: false,
          firefox60: false,
          firefox72: firefox.nightly,
          firefox79: true,
          chrome77: false,
          chrome84: {val: 'flagged', note_id: "chrome-promise-any", note_html: "Available behind the <a href='https://bugs.chromium.org/p/v8/issues/detail?id=9808'><code>--js-flags=\"--harmony-promise-any\"</code></a> flag in V8."},
          chrome85: true,
          safari14: true,
          safaritp: true,
          duktape2_0: false,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false,
          jerryscript2_3_0: false,
          graalvm20_3: graalvm.es2021flag,
          graalvm21: true
        }
      }
    ]
  },
  {
    name: 'WeakReferences',
    spec: 'https://github.com/tc39/proposal-weakrefs',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WeakRef',
    category: '2021 features',
    significance: 'large',
    subtests: [
      {
        name: 'WeakRef minimal support',
        spec: 'https://github.com/tc39/proposal-weakrefs#weak-references',
        exec: function () {/*
          var O = {};
          var weakref = new WeakRef(O);
          return weakref.deref() === O;
        */},
        res : {
          ie11: false,
          firefox2: false,
          firefox74: {
            val: 'flagged',
            note_id: 'firefox-weakrefs',
            note_html: 'The feature has to be enabled via <code>javascript.options.experimental.weakrefs</code> setting under <code>about:config</code>.'
          },
          firefox79: true,
          opera10_50: false,
          chrome65: false,
          chrome74: {val: 'flagged', note_id: "chrome-weakrefs", note_html: "Available behind the <a href='https://bugs.chromium.org/p/v8/issues/detail?id=8179'><code>--js-flags=\"--harmony-weak-refs --expose-gc\"</code></a> flag in V8."},
          chrome85: true,
          safari13: false,
          safari14_1: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: false,
          graalvm20: graalvm.es2021flag,
          graalvm21: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'FinalizationRegistry minimal support',
        spec: 'https://github.com/tc39/proposal-weakrefs#finalizers',
        exec: function () {/*
          var fr = new FinalizationRegistry(function () {});
          return Object.getPrototypeOf(fr) === FinalizationRegistry.prototype;
        */},
        res : {
          ie11: false,
          firefox2: false,
          firefox74: false,
          firefox78: { val: 'flagged', note_id: 'firefox-weakrefs' },
          firefox79: true,
          opera10_50: false,
          chrome65: false,
          chrome74: false,
          chrome85: true,
          safari14_1: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm19: false,
          graalvm20_3: graalvm.es2021flag,
          graalvm21: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      }
    ]
  },
  {
    name: 'Logical Assignment',
    category: '2021 features',
    significance: 'small',
    spec: 'https://github.com/tc39/proposal-logical-assignment/',
    subtests: [
      {
        name: '||= basic support',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Logical_OR_assignment',
        exec: function () {/*
        let a;
        let b = 0;
        let c = 1;
        a ||= 2;
        b ||= 2;
        c ||= 2;
        return a === 2 && b === 2 && c === 1;
      */},
        res: {
          babel7corejs2: true,
          closure: false,
          closure20210808: true,
          ie11: false,
          firefox60: false,
          firefox76: false,
          firefox77: firefox.nightly,
          firefox79: true,
          chrome80: false,
          chrome84: {val: 'flagged', note_id: "chrome-logical-assignment", note_html: "Available behind the <a href='https://github.com/v8/v8/commit/b151d8db22be308738192497a68c2c7c0d8d4070'><code>--js-flags=\"--logical-assignment\"</code></a> flag in V8."},
          chrome85: true,
          safari13: false,
          safari14: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm20_3: graalvm.es2021flag,
          graalvm21: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: '||= short-circuiting behaviour',
        exec: function () {/*
        let a = 1;
        let i = 1;
        a ||= ++i;
        return a === 1 && i === 1;
      */},
        res: {
          babel7corejs2: true,
          closure: false,
          closure20210808: true,
          ie11: false,
          firefox60: false,
          firefox76: false,
          firefox77: firefox.nightly,
          firefox79: true,
          chrome80: false,
          chrome84: {val: 'flagged', note_id: "chrome-logical-assignment"},
          chrome85: true,
          safari13: false,
          safari14: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm20_3: graalvm.es2021flag,
          graalvm21: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: '||= setter not unecessarily invoked',
        exec: function () {/*
        let i = 1;
        var obj = { get x() { return 1 }, set x(n) { i++; } };
        obj.x ||= 2;
        return i === 1;
      */},
        res: {
          babel7corejs2: true,
          closure: false,
          closure20210808: true,
          ie11: false,
          firefox60: false,
          firefox76: false,
          firefox77: firefox.nightly,
          firefox79: true,
          chrome80: false,
          chrome84: {val: 'flagged', note_id: "chrome-logical-assignment"},
          chrome85: true,
          safari13: false,
          safari14: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm20_3: graalvm.es2021flag,
          graalvm21: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: '&&= basic support',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Logical_AND_assignment',
        exec: function () {/*
        let a;
        let b = 0;
        let c = 1;
        a &&= 2;
        b &&= 2;
        c &&= 2;
        return typeof a === 'undefined' && b === 0 && c === 2;
      */},
        res: {
          babel7corejs2: true,
          closure: false,
          closure20210808: true,
          ie11: false,
          firefox60: false,
          firefox76: false,
          firefox77: firefox.nightly,
          firefox79: true,
          chrome80: false,
          chrome84: {val: 'flagged', note_id: "chrome-logical-assignment"},
          chrome85: true,
          safari13: false,
          safari14: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm20_3: graalvm.es2021flag,
          graalvm21: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: '&&= short-circuiting behaviour',
        exec: function () {/*
        let a;
        let i = 1;
        a &&= ++i;
        return typeof a === 'undefined' && i === 1;
      */},
        res: {
          babel7corejs2: true,
          closure: false,
          closure20210808: true,
          ie11: false,
          firefox60: false,
          firefox76: false,
          firefox77: firefox.nightly,
          firefox79: true,
          chrome80: false,
          chrome84: {val: 'flagged', note_id: "chrome-logical-assignment"},
          chrome85: true,
          safari13: false,
          safari14: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm20_3: graalvm.es2021flag,
          graalvm21: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: '&&= setter not unecessarily invoked',
        exec: function () {/*
        let i = 1;
        var obj = { get x() { return }, set x(n) { i++; } };
        obj.x &&= 2;
        return i === 1;
      */},
        res: {
          babel7corejs2: true,
          closure: false,
          closure20210808: true,
          ie11: false,
          firefox60: false,
          firefox76: false,
          firefox77: firefox.nightly,
          firefox79: true,
          chrome80: false,
          chrome84: {val: 'flagged', note_id: "chrome-logical-assignment"},
          chrome85: true,
          safari13: false,
          safari14: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm20_3: graalvm.es2021flag,
          graalvm21: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: '??= basic support',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Logical_nullish_assignment',
        exec: function () {/*
        let a;
        let b = 0;
        let c = 1;
        a ??= 2;
        b ??= 2;
        c ??= 2;
        return a === 2 && b === 0 && c === 1;
      */},
        res: {
          babel7corejs2: true,
          closure: false,
          closure20210808: true,
          ie11: false,
          firefox60: false,
          firefox76: false,
          firefox77: firefox.nightly,
          firefox79: true,
          chrome80: false,
          chrome84: {val: 'flagged', note_id: "chrome-logical-assignment"},
          chrome85: true,
          safari13: false,
          safari14: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm20_3: graalvm.es2021flag,
          graalvm21: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: '??= short-circuiting behaviour',
        exec: function () {/*
        let a = 1;
        let i = 1;
        a ??= ++i;
        return a === 1 && i === 1;
      */},
        res: {
          babel7corejs2: true,
          closure: false,
          closure20210808: true,
          ie11: false,
          firefox60: false,
          firefox76: false,
          firefox77: firefox.nightly,
          firefox79: true,
          chrome80: false,
          chrome84: {val: 'flagged', note_id: "chrome-logical-assignment"},
          chrome85: true,
          safari13: false,
          safari14: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm20_3: graalvm.es2021flag,
          graalvm21: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: '??= setter not unecessarily invoked',
        exec: function () {/*
        let i = 1;
        var obj = { get x() { return 1 }, set x(n) { i++; } };
        obj.x ??= 2;
        return i === 1;
      */},
        res: {
          babel7corejs2: true,
          closure: false,
          closure20210808: true,
          ie11: false,
          firefox60: false,
          firefox76: false,
          firefox77: firefox.nightly,
          firefox79: true,
          chrome80: false,
          chrome84: {val: 'flagged', note_id: "chrome-logical-assignment"},
          chrome85: true,
          safari13: false,
          safari14: true,
          safaritp: true,
          duktape2_0: false,
          jerryscript2_3_0: false,
          graalvm20_3: graalvm.es2021flag,
          graalvm21: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      }
    ]
  },
  {
    name: 'numeric separators',
    spec: 'https://github.com/tc39/proposal-numeric-separator',
    category: '2021 features',
    significance: 'small',
    exec: function () {/*
      return 1_000_000.000_001 === 1000000.000001 &&
        0b1010_0001_1000_0101 === 0b1010000110000101;
    */},
    res : {
      babel7corejs2: true,
      closure: false,
      closure20210808: true,
      typescript1corejs2: false,
      typescript2_7corejs2: true,
      ie11: false,
      firefox2: false,
      firefox10: false,
      firefox67: false,
      firefox68: firefox.nightly,
      firefox70: true,
      opera10_50: false,
      chrome67: chrome.harmony,
      chrome75: true,
      safari13: true,
      safaritp: true,
      duktape2_0: false,
      jerryscript2_3_0: false,
      jerryscript2_4_0: true,
      graalvm19: false,
      graalvm20: graalvm.es2020flag,
      graalvm20_1: true,
      hermes0_7_0: true,
      reactnative0_70_3: true,
      rhino1_7_13: false,
      rhino1_7_14: true,
    }
  },
  {
    name: 'instance class fields',
    category: '2022 features',
    significance: 'medium',
    spec: 'https://github.com/tc39/proposal-class-fields',
    subtests: [
      {
        name: 'public instance class fields',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes/Class_elements#Public_instance_fields',
        exec: function () {/*
          class C {
            x = 'x';
          }
          return new C().x === 'x';
        */},
        res: {
          babel6corejs2: true,
          tr: true,
          typescript1corejs2: true,
          ie11: false,
          firefox2: false,
          firefox67: firefox.classFields,
          firefox69: true,
          opera10_50: false,
          chrome65: chrome.harmony,
          chrome72: true,
          safari14: true,
          safaritp: true,
          duktape2_0: false,
          graalvm19: false,
          graalvm20: true,
          hermes0_7_0: false,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'private instance class fields basic support',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes/Class_elements#Private_instance_fields',
        exec: function () {/*
          class C {
            #x;
            constructor(x) {
              this.#x = x;
            }
            x() {
              return this.#x;
            }
          }
          return new C(42).x() === 42;
        */},
        res: {
          babel7corejs2: true,
          ie11: false,
          firefox2: false,
          firefox67: firefox.privateClassFields,
          firefox80: firefox.privateFields,
          firefox90: true,
          opera10_50: false,
          chrome66: chrome.harmony,
          chrome74: true,
          safari14_1: true,
          safaritp: true,
          duktape2_0: false,
          graalvm19: false,
          graalvm20: true,
          hermes0_7_0: false,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'private instance class fields initializers',
        exec: function () {/*
          class C {
            #x = 42;
            x() {
              return this.#x;
            }
          }
          return new C().x() === 42;
        */},
        res: {
          babel7corejs2: true,
          ie11: false,
          firefox2: false,
          firefox67: firefox.privateClassFields,
          firefox80: firefox.privateFields,
          firefox90: true,
          opera10_50: false,
          chrome66: chrome.harmony,
          chrome74: true,
          safari14_1: true,
          safaritp: true,
          duktape2_0: false,
          graalvm19: false,
          graalvm20: true,
          hermes0_7_0: false,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'optional private instance class fields access',
        exec: function () {/*
          class C {
            #x = 42;
            x(o = this) {
              return o?.#x;
            }
          }
          return new C().x() === 42 && new C().x(null) === void undefined;
        */},
        res: {
          babel7corejs2: true,
          babel7corejs3: true,
          ie11: false,
          firefox2: false,
          firefox80: firefox.privateFields,
          firefox90: true,
          chrome1: false,
          chrome83: false,
          chrome84: true,
          safari1: false,
          safari13_1: false,
          safari14_1: true,
          safaritp: true,
          duktape2_0: false,
          opera10_50: false,
          graalvm20: false,
          graalvm20_3: true,
          typescript3_8corejs3: false,
          hermes0_7_0: false,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'optional deep private instance class fields access',
        exec: function () {/*
          class C {
            #x = 42;
            x(o = { p: this }) {
              return o?.p.#x;
            }
          }
          return new C().x() === 42 && new C().x(null) === void undefined;
        */},
        res: {
          babel7corejs2: true,
          babel7corejs3: true,
          ie11: false,
          firefox2: false,
          firefox74: firefox.privateClassFields,
          firefox80: firefox.privateFields,
          firefox90: true,
          chrome1: false,
          chrome78: {val: 'flagged', note_id: "chrome-optional-chaining", note_html: "The feature has to be enabled via <code>--js-flags=\"--harmony-optional-chaining\"</code> flag"},
          chrome80: true,
          safari1: false,
          safari13_1: false,
          safari14_1: true,
          safaritp: true,
          opera10_50: false,
          duktape2_0: false,
          graalvm20: false,
          graalvm20_3: true,
          typescript3_8corejs3: false,
          hermes0_7_0: false,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'computed instance class fields',
        exec: function () {/*
          class C {
            ['x'] = 42;
          }
          return new C().x === 42;
        */},
        res: {
          babel7corejs2: true,
          ie11: false,
          firefox2: false,
          firefox66: false,
          firefox68: firefox.classFields,
          firefox69: true,
          opera10_50: false,
          chrome73: true,
          safari14: true,
          safaritp: true,
          duktape2_0: false,
          graalvm19: false,
          graalvm20: true,
          hermes0_7_0: false,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'resolving identifier in parent scope',
        exec: function () {/*
          {
            let a = ["hello world"];
            class MyClass {
              // The parenthesis below are required to trigger https://bugs.webkit.org/show_bug.cgi?id=236843
              c = a[(0)];
            }
            return new MyClass().c === a[0];
          }
        */},
        res: {
          firefox122: true,
          chrome74: true,
          chrome124: true,
          firefox69: true,
          safari15: false,
          safari16: true,
          safari17: true,
          safaritp: true,
        }
      }
    ]
  },
  {
    name: 'static class fields',
    category: '2022 features',
    significance: 'medium',
    spec: 'https://github.com/tc39/proposal-static-class-features/',
    subtests: [
      {
        name: 'public static class fields',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes/Class_elements#Public_static_fields',
        exec: function () {/*
          class C {
            static x = 'x';
          }
          return C.x === 'x';
        */},
        res: {
          babel6corejs2: true,
          tr: true,
          typescript1corejs2: true,
          ie11: false,
          firefox2: false,
          firefox74: false,
          firefox75: true,
          opera10_50: false,
          chrome71: chrome.harmony,
          chrome72: true,
          safari14_1: true,
          safaritp: true,
          duktape2_0: false,
          graalvm19: false,
          graalvm20: true,
          hermes0_7_0: false,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'static class fields use [[Define]]',
        exec: function () { /*
          return (class X { static name = "name"; }).name === 'name';
        */},
        res: {
          ie11: false,
          edge18: false,
          chrome73: true,
          chrome90: true,
          chrome94: true,
          chrome96: true,
          chrome97: false,
          chrome98: true,
          firefox74: false,
          firefox75: true,
          firefox91: true,
          firefox95: true,
          firefox96: true,
          opera10_50: false,
          node11_0: false,
          node12_0: true,
          node12_5: true,
          node12_9: true,
          node12_11: true,
          node13_0: true,
          node13_2: true,
          node14_0: true,
          node14_5: true,
          node14_6: true,
          node15_0: true,
          node16_0: true,
          node16_9: true,
          node16_11: true,
          safari15: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          graalvm22_2: true,
          hermes0_7_0: false,
          reactnative0_70_3: true,
          rhino1_7_15: false
        }
      },
      {
        name: 'private static class fields',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes/Class_elements#Private_static_fields',
        exec: function () {/*
          class C {
            static #x = 42;
            x() {
              return C.#x;
            }
          }
          return new C().x() === 42;
        */},
        res: {
          babel7corejs2: true,
          ie11: false,
          firefox2: false,
          firefox80: firefox.privateFields,
          firefox90: true,
          opera10_50: false,
          chrome74: true,
          safari14_1: true,
          safaritp: true,
          duktape2_0: false,
          graalvm19: false,
          graalvm20: true,
          hermes0_7_0: false,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: 'computed static class fields',
        exec: function () {/*
          class C {
            static ['x'] = 42;
          }
          return C.x === 42;
        */},
        res: {
          babel7corejs2: true,
          ie11: false,
          firefox2: false,
          firefox74: false,
          firefox75: true,
          opera10_50: false,
          chrome73: true,
          safari14_1: true,
          safaritp: true,
          duktape2_0: false,
          graalvm19: false,
          graalvm20: true,
          hermes0_7_0: false,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      }
    ]
  },
  {
    name: 'private class methods',
    category: '2022 features',
    significance: 'medium',
    spec: 'https://github.com/tc39/proposal-private-methods',
    subtests: [
      {
        name: 'private instance methods',
        exec: function () {/*
          class C {
            #x() { return 42; }
            x() {
              return this.#x();
            }
          }
          return new C().x() === 42;
        */},
        res: {
          babel7corejs2: true,
          ie11: false,
          firefox60: false,
          firefox68: false,
          firefox75: false,
          firefox81: {
            val: 'flagged',
            note_id: 'ff-private-instance-methods-and-accessors',
            note_html: 'The feature has to be enabled via <code>javascript.options.experimental.private_fields</code> and <code>javascript.options.experimental.private_methods</code> settings under <code>about:config</code>.'
          },
          firefox90: true,
          opera10_50: false,
          chrome79: chrome.harmony,
          chrome84: true,
          duktape2_0: false,
          safari13: false,
          safari15: true,
          safaritp: true,
          graalvm20: false,
          graalvm20_1: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'private static methods',
        exec: function () {/*
          class C {
            static #x() { return 42; }
            x() {
              return C.#x();
            }
          }
          return new C().x() === 42;
        */},
        res: {
          babel7corejs2: true,
          ie11: false,
          firefox60: false,
          firefox68: false,
          firefox75: false,
          firefox82: {
            val: 'flagged',
            note_id: 'ff-private-instance-methods-and-accessors'
          },
          firefox90: true,
          opera10_50: false,
          chrome79: chrome.harmony,
          chrome84: true,
          duktape2_0: false,
          safari13: false,
          safari15: true,
          safaritp: true,
          graalvm20: false,
          graalvm20_1: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'private accessor properties',
        exec: function () {/*
          var y = false;
          class C {
            get #x() { return 42; }
            set #x(x) { y = x; }
            x() {
              this.#x = true;
              return this.#x;
            }
          }
          return new C().x() === 42 && y;
        */},
        res: {
          babel7corejs2: true,
          ie11: false,
          firefox60: false,
          firefox68: false,
          firefox75: false,
          firefox81: {
            val: 'flagged',
            note_id: 'ff-private-instance-methods-and-accessors'
          },
          firefox90: true,
          opera10_50: false,
          chrome79: chrome.harmony,
          chrome84: true,
          duktape2_0: false,
          safari13: false,
          safari15: true,
          safaritp: true,
          graalvm20: false,
          graalvm20_1: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'private static accessor properties',
        exec: function () {/*
          var y = false;
          class C {
            static get #x() { return 42; }
            static set #x(x) { y = x; }
            x() {
              C.#x = true;
              return C.#x;
            }
          }
          return new C().x() === 42 && y;
        */},
        res: {
          babel7corejs2: true,
          ie11: false,
          firefox60: false,
          firefox68: false,
          firefox75: false,
          firefox82: {
            val: 'flagged',
            note_id: 'ff-private-instance-methods-and-accessors'
          },
          firefox90: true,
          opera10_50: false,
          chrome79: chrome.harmony,
          chrome84: true,
          duktape2_0: false,
          safari13: false,
          safari15: true,
          safaritp: true,
          graalvm20: false,
          graalvm20_1: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      }
    ]
  },
  {
    name: 'Ergonomic brand checks for private fields',
    category: '2022 features',
    significance: 'small',
    spec: 'https://github.com/tc39/proposal-private-fields-in-in',
    exec: function () {/*
      class A {
        #x;
        static check(obj) {
          return #x in obj;
        }
      }
      return A.check(new A) && !A.check({});
    */},
    res: {
      babel6corejs2: false,
      babel7corejs2: true,
      babel7corejs3: true,
      chrome1: false,
      chrome91: true,
      edge18: false,
      firefox2: false,
      firefox90: true,
      ie11: false,
      opera10_50: false,
      safari12: false,
      safari15: true,
      duktape2_0: false,
      graalvm21_3_3: graalvm.esStagingFlag,
      graalvm22_2: true,
      hermes0_7_0: false,
      reactnative0_70_3: true,
      rhino1_7_13: false
    }
  },
  {
    name: '.at() method on the built-in indexables',
    category: '2022 features',
    significance: 'tiny',
    spec: 'https://github.com/tc39/proposal-relative-indexing-method/',
    subtests: [
      {
        name: 'Array.prototype.at()',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/at',
        exec: function () {/*
        var arr = [1, 2, 3];
        return arr.at(0) === 1
          && arr.at(-3) === 1
          && arr.at(1) === 2
          && arr.at(-2) === 2
          && arr.at(2) === 3
          && arr.at(-1) === 3
          && arr.at(3) === undefined
          && arr.at(-4) === undefined;
      */},
        res: {
          closure: false,
          closure20220502: {
            val: false,
            note_id: 'closure-at-method',
            note_html: 'Requires native support for <code>Math.trunc</code>'
          },
          closure20220719: true,
          ie11: false,
          firefox68: false,
          firefox85: firefox.nightly,
          firefox90: true,
          chrome85: false,
          chrome92: true,
          safari14_1: {
            val: 'flagged',
            note_id: 'safari-at-method',
            note_html: 'The feature has to be enabled via <code>jscOptions=--useAtMethod=true</code> flag.'
          },
          safari15_4: true,
          safaritp: true,
          duktape2_0: false,
          babel7corejs3: babel.corejs,
          typescript4corejs3: typescript.corejs,
          graalvm21: graalvm.es2022flag,
          graalvm21_3_3: graalvm.esStagingFlag,
          graalvm22_2: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false,
          rhino1_7_15: true
        }
      },
      {
        name: 'String.prototype.at()',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/at',
        exec: function () {/*
        var str = 'abc';
        return str.at(0) === 'a'
          && str.at(-3) === 'a'
          && str.at(1) === 'b'
          && str.at(-2) === 'b'
          && str.at(2) === 'c'
          && str.at(-1) === 'c'
          && str.at(3) === undefined
          && str.at(-4) === undefined;
      */},
        res: {
          closure: false,
          closure20220502: {
            val: false,
            note_id: 'closure-at-method'
          },
          closure20220719: true,
          ie11: false,
          firefox68: false,
          firefox85: firefox.nightly,
          firefox90: true,
          chrome85: false,
          chrome92: true,
          safari14_1: {
            val: 'flagged',
            note_id: 'safari-at-method'
          },
          safari15_4: true,
          safaritp: true,
          duktape2_0: false,
          babel7corejs3: babel.corejs,
          typescript4corejs3: typescript.corejs,
          graalvm21: graalvm.es2022flag,
          graalvm21_3_3: graalvm.esStagingFlag,
          graalvm22_2: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false,
          rhino1_7_15: true
        }
      },
      {
        name: '%TypedArray%.prototype.at()',
        exec: function () {/*
         return [
           'Int8Array',
           'Uint8Array',
           'Uint8ClampedArray',
           'Int16Array',
           'Uint16Array',
           'Int32Array',
           'Uint32Array',
           'Float32Array',
           'Float64Array'
         ].every(function (TypedArray) {
           var Constructor = globalThis[TypedArray];
           if (typeof Constructor !== 'function') {
             return false;
           }
           var arr = new Constructor([1, 2, 3]);
           return arr.at(0) === 1
             && arr.at(-3) === 1
             && arr.at(1) === 2
             && arr.at(-2) === 2
             && arr.at(2) === 3
             && arr.at(-1) === 3
             && arr.at(3) === undefined
             && arr.at(-4) === undefined;
         });
      */},
        res: {
          closure: false,
          closure20220502: {
            val: false,
            note_id: 'closure-typed-array',
            note_html: 'Requires native support for typed arrays'
          },
          ie11: false,
          firefox68: false,
          firefox85: firefox.nightly,
          firefox90: true,
          chrome85: false,
          chrome92: true,
          safari14_1: {
            val: 'flagged',
            note_id: 'safari-at-method'
          },
          safari15_4: true,
          safaritp: true,
          duktape2_0: false,
          babel7corejs3: babel.corejs,
          typescript4corejs3: typescript.corejs,
          graalvm21: graalvm.es2022flag,
          graalvm21_3_3: graalvm.esStagingFlag,
          graalvm22_2: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false,
          rhino1_7_15: true
        }
      }
    ]
  },
  {
    name: 'Object.hasOwn',
    category: '2022 features',
    significance: 'small',
    spec: 'https://github.com/tc39/proposal-accessible-object-hasownproperty',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/hasOwn',
    subtests: [
      {
        name: "Basic functionality",
        exec: function () {/*
        return Object.hasOwn({ x: 2 }, "x") === true;
      */},
        res: {
          babel7corejs3: babel.corejs,
          closure20220719: true,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          chrome1: false,
          chrome90: false,
          chrome93: true,
          edge18: false,
          firefox2: false,
          firefox90: false,
          firefox91: firefox.nightly,
          firefox92: true,
          opera10_50: false,
          safari12: false,
          safari15_4: true,
          safaritp: true,
          duktape2_0: false,
          graalvm21_3_3: graalvm.esStagingFlag,
          graalvm22_2: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false,
          rhino1_7_15: true
        }
      },
      {
        name: "ToObject called before ToPropertyKey",
        exec: function () {/*
        var ok = !!Object.hasOwn;
        try {
          Object.hasOwn(null, { toString: function () { ok = false } });
          return false;
        } catch (e) {
          return ok;
        }
      */},
        res: {
          babel7corejs3: babel.corejs,
          closure20220719: true,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          chrome1: false,
          chrome90: false,
          chrome93: true,
          edge18: false,
          firefox2: false,
          firefox90: false,
          firefox91: firefox.nightly,
          firefox92: true,
          opera10_50: false,
          safari12: false,
          safari15_4: true,
          safaritp: true,
          duktape2_0: false,
          graalvm21_3_3: graalvm.esStagingFlag,
          graalvm22_2: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false,
          rhino1_7_15: true
        }
      }
    ]
  },
  {
    name: 'Class static initialization blocks',
    category: '2022 features',
    significance: 'small',
    spec: 'https://github.com/tc39/proposal-class-static-block',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes/Static_initialization_blocks',
    exec: function () {/*
    let ok = false;
    class A {
      static { ok = true; }
    }
    return ok;
  */},
    res: {
      babel6corejs2: false,
      babel7corejs2: true,
      babel7corejs3: true,
      chrome1: false,
      chrome91: {
        val: 'flagged',
        note_id: 'ch-static-init-blocks',
        note_html: 'The feature has to be enabled via <code>harmony_class_static_blocks</code> flag.'
      },
      chrome94: true,
      safari13: false,
      edge18: false,
      firefox2: false,
      firefox87: false,
      firefox90: {
        val: 'flagged',
        note_id: 'ff-static-init-blocks',
        note_html: 'The feature has to be enabled via <code>javascript.options.experimental.class_static_blocks=true</code> flag.'
      },
      firefox93: true,
      ie11: false,
      opera10_50: false,
      safari16_4: true,
      duktape2_0: false,
      graalvm21_3_3: graalvm.esStagingFlag,
      graalvm22_2: true,
      hermes0_7_0: false,
      reactnative0_70_3: false,
      rhino1_7_13: false
    },
  },
  {
    name: 'Error.cause property',
    category: '2022 features',
    significance: 'small',
    spec: 'https://github.com/tc39/proposal-error-cause',
    subtests: [
      {
        name: "Error has cause",
        exec: function () {/*
        var error = new Error('error', { cause: 'cause' })
        return error.hasOwnProperty('cause') && error.cause === 'cause';
        */},
        res: {
          ie11: false,
          chrome1: false,
          chrome92: false,
          chrome93: true,
          edge90: false,
          firefox45: false,
          firefox90: false,
          firefox91: true,
          safari14: false,
          safari15: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          graalvm22_2: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_14: false,
        }
      },
      {
        name: "Error.prototype lacks cause",
        exec: function () {/*
        return !('cause' in Error.prototype);
        */},
        res: {
          ie11: false,
          chrome1: false,
          chrome92: false,
          chrome93: false,
          chrome94: true,
          edge90: false,
          firefox45: false,
          firefox90: false,
          firefox91: true,
          safari14: false,
          safari15: true,
          duktape2_0: true,
          graalvm21_3_3: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_14: true,
        }
      },
      {
        name: "EvalError has cause",
        exec: function () {/*
        var error = new EvalError('error', { cause: 'cause' })
        return error.hasOwnProperty('cause') && error.cause === 'cause';
        */},
        res: {
          ie11: false,
          chrome1: false,
          chrome92: false,
          chrome93: true,
          edge90: false,
          firefox45: false,
          firefox90: false,
          firefox91: true,
          safari14: false,
          safari15: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          graalvm22_2: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_14: false,
        }
      },
      {
        name: "EvalError.prototype lacks cause",
        exec: function () {/*
        return !('cause' in EvalError.prototype);
        */},
        res: {
          ie11: false,
          chrome1: false,
          chrome92: false,
          chrome93: false,
          chrome94: true,
          edge90: false,
          firefox45: false,
          firefox90: false,
          firefox91: true,
          safari14: false,
          safari15: true,
          duktape2_0: true,
          graalvm21_3_3: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_14: true,
        }
      },
      {
        name: "RangeError has cause",
        exec: function () {/*
        var error = new RangeError('error', { cause: 'cause' })
        return error.hasOwnProperty('cause') && error.cause === 'cause';
        */},
        res: {
          ie11: false,
          chrome1: false,
          chrome92: false,
          chrome93: true,
          edge90: false,
          firefox45: false,
          firefox90: false,
          firefox91: true,
          safari14: false,
          safari15: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          graalvm22_2: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_14: false,
        }
      },
      {
        name: "RangeError.prototype lacks cause",
        exec: function () {/*
        return !('cause' in RangeError.prototype);
        */},
        res: {
          ie11: false,
          chrome1: false,
          chrome92: false,
          chrome93: false,
          chrome94: true,
          edge90: false,
          firefox45: false,
          firefox90: false,
          firefox91: true,
          safari14: false,
          safari15: true,
          duktape2_0: true,
          graalvm21_3_3: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_14: true,
        }
      },
      {
        name: "ReferenceError has cause",
        exec: function () {/*
        var error = new ReferenceError('error', { cause: 'cause' })
        return error.hasOwnProperty('cause') && error.cause === 'cause';
        */},
        res: {
          ie11: false,
          chrome1: false,
          chrome92: false,
          chrome93: true,
          edge90: false,
          firefox45: false,
          firefox90: false,
          firefox91: true,
          safari14: false,
          safari15: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          graalvm22_2: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_14: false,
        }
      },
      {
        name: "ReferenceError.prototype lacks cause",
        exec: function () {/*
        return !('cause' in ReferenceError.prototype);
        */},
        res: {
          ie11: false,
          chrome1: false,
          chrome92: false,
          chrome93: false,
          chrome94: true,
          edge90: false,
          firefox45: false,
          firefox90: false,
          firefox91: true,
          safari14: false,
          safari15: true,
          duktape2_0: true,
          graalvm21_3_3: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_14: true,
        }
      },
      {
        name: "SyntaxError has cause",
        exec: function () {/*
        var error = new SyntaxError('error', { cause: 'cause' })
        return error.hasOwnProperty('cause') && error.cause === 'cause';
        */},
        res: {
          ie11: false,
          chrome1: false,
          chrome92: false,
          chrome93: true,
          edge90: false,
          firefox45: false,
          firefox90: false,
          firefox91: true,
          safari14: false,
          safari15: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          graalvm22_2: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_14: false,
        }
      },
      {
        name: "SyntaxError.prototype lacks cause",
        exec: function () {/*
        return !('cause' in SyntaxError.prototype);
        */},
        res: {
          ie11: false,
          chrome1: false,
          chrome92: false,
          chrome93: false,
          chrome94: true,
          edge90: false,
          firefox45: false,
          firefox90: false,
          firefox91: true,
          safari14: false,
          safari15: true,
          duktape2_0: true,
          graalvm21_3_3: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_14: true,
        }
      },
      {
        name: "TypeError has cause",
        exec: function () {/*
        var error = new TypeError('error', { cause: 'cause' })
        return error.hasOwnProperty('cause') && error.cause === 'cause';
        */},
        res: {
          ie11: false,
          chrome1: false,
          chrome92: false,
          chrome93: true,
          edge90: false,
          firefox45: false,
          firefox90: false,
          firefox91: true,
          safari14: false,
          safari15: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          graalvm22_2: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_14: false,
        }
      },
      {
        name: "TypeError.prototype lacks cause",
        exec: function () {/*
        return !('cause' in TypeError.prototype);
        */},
        res: {
          ie11: false,
          chrome1: false,
          chrome92: false,
          chrome93: false,
          chrome94: true,
          edge90: false,
          firefox45: false,
          firefox90: false,
          firefox91: true,
          safari14: false,
          safari15: true,
          duktape2_0: true,
          graalvm21_3_3: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_14: true,
        }
      },
      {
        name: "URIError has cause",
        exec: function () {/*
        var error = new URIError('error', { cause: 'cause' })
        return error.hasOwnProperty('cause') && error.cause === 'cause';
        */},
        res: {
          ie11: false,
          chrome1: false,
          chrome92: false,
          chrome93: true,
          edge90: false,
          firefox45: false,
          firefox90: false,
          firefox91: true,
          safari14: false,
          safari15: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          graalvm22_2: true,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_14: false,
        }
      },
      {
        name: "URIError.prototype lacks cause",
        exec: function () {/*
        return !('cause' in URIError.prototype);
        */},
        res: {
          ie11: false,
          chrome1: false,
          chrome92: false,
          chrome93: false,
          chrome94: true,
          edge90: false,
          firefox45: false,
          firefox90: false,
          firefox91: true,
          safari14: false,
          safari15: true,
          duktape2_0: true,
          graalvm21_3_3: true,
          hermes0_7_0: true,
          reactnative0_70_3: true,
          rhino1_7_14: true,
        }
      },
      {
        name: "AggregateError has cause",
        exec: function () {/*
        var error = new AggregateError([], 'error', { cause: 'cause' })
        return error.hasOwnProperty('cause') && error.cause === 'cause';
        */},
        res: {
          ie11: false,
          chrome1: false,
          chrome92: false,
          chrome93: true,
          edge90: false,
          firefox45: false,
          firefox90: false,
          firefox91: true,
          safari14: false,
          safari15: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          graalvm22_2: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_14: false,
        }
      },
      {
        name: "AggregateError.prototype lacks cause",
        exec: function () {/*
        return !('cause' in AggregateError.prototype);
        */},
        res: {
          ie11: false,
          chrome1: false,
          chrome92: false,
          chrome93: false,
          chrome94: true,
          edge90: false,
          firefox45: false,
          firefox90: false,
          firefox91: true,
          safari14: false,
          safari15: true,
          duktape2_0: false,
          graalvm21_3_3: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_14: false,
        }
      },
    ]
  },
  {
    name: 'RegExp Match Indices (`hasIndices` / `d` flag)',
    category: '2022 features',
    significance: 'small',
    spec: 'https://github.com/tc39/proposal-regexp-match-indices',
    subtests: [
      {
        name: 'constructor supports it',
        exec: function () {/*
            return new RegExp('a', 'd') instanceof RegExp;
        */},
        res: {
          ie11: false,
          firefox68: false,
          firefox78: false,
          firefox91: true,
          safari15: true,
          chrome90: true,
          graalvm21_3_3: graalvm.esStagingFlag,
          graalvm22_2: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_15: false
        }
      },
      {
        name: 'shows up in flags',
        exec: function () {/*
          var expected = ['hasIndices'];
          // Sorted alphabetically by shortname – "dgimsuy".
          if ('global' in RegExp.prototype) expected.push('global');
          if ('ignoreCase' in RegExp.prototype) expected.push('ignoreCase');
          if ('multiline' in RegExp.prototype) expected.push('multiline');
          if ('dotAll' in RegExp.prototype) expected.push('dotAll');
          if ('unicode' in RegExp.prototype) expected.push('unicode');
          if ('sticky' in RegExp.prototype) expected.push('sticky');
          var actual = [];
          var p = new Proxy({}, { get: function (o, k) { actual.push(k); return o[k]; }});
          Object.getOwnPropertyDescriptor(RegExp.prototype, 'flags').get.call(p);
          if (expected.length !== actual.length) return false;
          for (var i = 0; i < expected.length; i++) {
            if (expected[i] !== actual[i]) return false;
          }
          return true;
        */},
        res: {
          ie11: false,
          node16_0: false,
          firefox68: false,
          firefox78: false,
          firefox91: true,
          firefox116: false,
          safari15: true,
          chrome90: false,
          graalvm21_3_3: graalvm.esStagingFlag,
          graalvm22_2: true,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_15: false
        }
      }
    ]
  },
  {
    name: 'Array find from last',
    category: '2023 features',
    significance: 'small',
    spec: 'https://github.com/tc39/proposal-array-find-from-last',
    subtests: [
      {
        name: "Array.prototype.findLast",
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/findLast',
        exec: function () {/*
          var arr = [{ x: 1 }, { x: 2 }, { x: 1 }, { x: 2 }];
          return arr.findLast(function (o) { return o.x === 1; }) === arr[2];
        */},
        res: {
          babel7corejs3: babel.corejs,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          chrome1: false,
          chrome90: false,
          chrome96: false,
          chrome97: true,
          edge18: false,
          firefox2: false,
          firefox89: false,
          firefox102: false,
          firefox103: {
            val: 'flagged',
            note_id: 'firefox-arrayfindfromlast',
            note_html: 'The feature has to be enabled via <code>javascript.options.experimental.array_find_last</code> setting under <code>about:config</code>.'
          },
          firefox104: true,
          opera10_50: false,
          safari12: false,
          safari15_4: true,
          safaritp: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          graalvm22_2: graalvm.esStagingFlag,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      },
      {
        name: "Array.prototype.findLastIndex",
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/findLastIndex',
        exec: function () {/*
          var arr = [{ x: 1 }, { x: 2 }, { x: 1 }, { x: 2 }];
          return arr.findLastIndex(function (o) { return o.x === 1; }) === 2;
        */},
        res: {
          babel7corejs3: babel.corejs,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          chrome1: false,
          chrome90: false,
          chrome96: false,
          chrome97: true,
          edge18: false,
          firefox2: false,
          firefox89: false,
          firefox102: false,
          firefox103: { val: 'flagged', note_id: 'firefox-arrayfindfromlast' },
          firefox104: true,
          opera10_50: false,
          safari12: false,
          safari15_4: true,
          safaritp: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          graalvm22_2: graalvm.esStagingFlag,
          hermes0_7_0: false,
          hermes0_12_0: true,
          reactnative0_70_3: true,
          rhino1_7_13: false
        }
      }
    ]
  },
  {
    name: 'Hashbang Grammar',
    category: '2023 features',
    significance: 'tiny',
    spec: 'https://github.com/tc39/proposal-hashbang/',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Lexical_grammar#Hashbang_comments',
    exec: function () {/*
      try {
        return !eval('#!/wash/your/hands');
      } catch (e) {
        return false
      }
    */},
    res: {
      chrome1: false,
      chrome74: true,
      firefox2: false,
      firefox67: true,
      ie11: false,
      opera10_50: false,
      edge18: false,
      safari1: false,
      safari13: false,
      safari13_1: true,
      duktape2_0: false,
      graalvm19: false,
      graalvm20_1: true,
      babel7corejs3: false,
      typescript3_2corejs3: false,
      closure: false,
      hermes0_7_0: true,
      reactnative0_70_3: true,
      rhino1_7_13: false,
      rhino1_7_15: true
    }
  },
  {
    name: 'Change Array by copy',
    category: '2023 features',
    significance: 'small',
    spec: 'https://github.com/tc39/proposal-change-array-by-copy',
    subtests: [
      {
        name: "Array.prototype.toReversed()",
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/toReversed',
        exec: function () {/*
          var arr = [1, 2, 3];
          return arr.toReversed()[0] === 3 && arr[0] === 1;
        */},
        res: {
          babel7corejs3: babel.corejs,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          chrome94: false,
          chrome109: false,
          chrome110: true,
          firefox45: false,
          firefox95: {val: "flagged", note_id: "fx-change-array-by-copy", note_html: 'The feature has to be enabled via --enable-change-array-by-copy flag'},
          firefox115: true,
          safari15_5: false,
          safari16: true,
        }
      },
      {
        name: "Array.prototype.toSorted()",
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/toSorted',
        exec: function () {/*
          var arr = ['C', 'A', 'B'];
          return arr.toSorted()[0] === 'A' && arr[0] === 'C';
        */},
        res: {
          babel7corejs3: babel.corejs,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          chrome94: false,
          chrome109: false,
          chrome110: true,
          firefox45: false,
          firefox95: {val: "flagged", note_id: "fx-change-array-by-copy"},
          firefox115: true,
          safari15_5: false,
          safari16: true,
        }
      },
      {
        name: "Array.prototype.toSpliced()",
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/toSpliced',
        exec: function () {/*
          var arr = ['A', 'C'];
          return arr.toSpliced(1, 0, 'B')[1] === 'B' && arr[1] === 'C';
        */},
        res: {
          babel7corejs3: babel.corejs,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          chrome94: false,
          chrome109: false,
          chrome110: true,
          firefox45: false,
          firefox95: {val: "flagged", note_id: "fx-change-array-by-copy"},
          firefox115: true,
          safari15_5: false,
          safari16: true,
        }
      },
      {
        name: "Array.prototype.with()",
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/with',
        exec: function () {/*
          var arr = ['A', 'X', 'C'];
          return arr.with(1, 'B')[1] === 'B' && arr[1] === 'X';
        */},
        res: {
          babel7corejs3: babel.corejs,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          chrome94: false,
          chrome109: false,
          chrome110: true,
          firefox45: false,
          firefox95: {val: "flagged", note_id: "fx-change-array-by-copy"},
          firefox115: true,
          safari15_5: false,
          safari16: true,
        }
      },
      {
        name: "TypedArray.prototype.toReversed()",
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray/toReversed',
        exec: function () {/*
          var arr = new Uint8Array([1, 2, 3]);
          return arr.toReversed()[0] == 3 && arr[0] == 1;
        */},
        res: {
          ie11: false,
          chrome94: false,
          chrome109: false,
          chrome110: true,
          firefox45: false,
          firefox95: {val: "flagged", note_id: "fx-change-array-by-copy"},
          firefox115: true,
          safari15_5: false,
          safari16: true,
        }
      },
      {
        name: "TypedArray.prototype.toSorted()",
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray/toSorted',
        exec: function () {/*
          var arr = new Uint8Array([3, 1, 2]);
          return arr.toSorted()[0] == 1 && arr[0] == 3;
        */},
        res: {
          ie11: false,
          chrome94: false,
          chrome109: false,
          chrome110: true,
          firefox45: false,
          firefox95: {val: "flagged", note_id: "fx-change-array-by-copy"},
          firefox115: true,
          safari15_5: false,
          safari16: true,
        }
      },
      {
        name: "TypedArray.prototype.with()",
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray/with',
        exec: function () {/*
          var arr = new Uint8Array([1, 0, 2]);
          return arr.with(1, 2)[1] == 2 && arr[1] == 0;
        */},
        res: {
          ie11: false,
          chrome94: false,
          chrome109: false,
          chrome110: true,
          firefox45: false,
          firefox95: {val: "flagged", note_id: "fx-change-array-by-copy"},
          firefox115: true,
          safari15_5: false,
          safari16: true,
        }
      },
    ]
  },
  {
    name: 'RegExp `v` flag',
    category: '2024 features',
    significance: 'small',
    spec: 'https://github.com/tc39/proposal-regexp-v-flag',
    subtests: [
      {
        name: 'set notations',
        exec: function () {/*
          return /[\p{ASCII}&&\p{Decimal_Number}]/v.test("0")
          && /[\p{Any}--[\x01-\u{10ffff}]]/v.test("\0")
        */},
        res: {
          chrome110: false,
          chrome111: chrome.harmony,
          chrome112: true,
          firefox91: false,
          firefox102: false,
          firefox115: false,
          firefox116: true,
          ie11: false,
          safari16_6: false,
          safari17: true,
          safaritp: true,
          rhino1_7_15: false,
        }
      },
      {
        name: 'properties of Strings',
        exec: function () {/*
          return /^\p{Emoji_Keycap_Sequence}$/v.test("*\uFE0F\u20E3")
          && !/^\p{Emoji_Keycap_Sequence}$/v.test("*");
        */},
        res: {
          chrome110: false,
          chrome111: chrome.harmony,
          chrome112: true,
          firefox91: false,
          firefox102: false,
          firefox115: false,
          firefox116: true,
          ie11: false,
          safari16_6: false,
          safari17: true,
          safaritp: true,
          rhino1_7_15: false,
        }
      },
      {
        name: 'constructor supports it',
        exec: function () {/*
            return new RegExp('a', 'v') instanceof RegExp;
        */},
        res: {
          chrome110: false,
          chrome111: chrome.harmony,
          chrome112: true,
          firefox91: false,
          firefox102: false,
          firefox115: false,
          firefox116: true,
          ie11: false,
          safari16_6: false,
          safari17: true,
          safaritp: true,
          rhino1_7_15: false,
        }
      },
      {
        name: 'shows up in flags',
        exec: function () {/*
          var flags = [];
          var p = new Proxy({}, { get: function (o, k) { flags.push(k); return o[k]; }});
          Object.getOwnPropertyDescriptor(RegExp.prototype, 'flags').get.call(p);
          return flags.indexOf("unicodeSets") !== -1;
        */},
        res: {
          chrome110: false,
          chrome111: chrome.harmony,
          chrome112: true,
          firefox91: false,
          firefox102: false,
          firefox115: false,
          firefox116: true,
          ie11: false,
          safari16_6: false,
          safari17: true,
          safaritp: true,
          rhino1_7_15: false,
        }
      },
      {
        name: 'Unicode 15.1',
        exec: function () {/*
        return /^\p{RGI_Emoji}$/v.test("🐦‍🔥");
      */},
        res: {
          chrome117: false,
          chrome118: false,
          chrome124: false,
          chrome125: true,
          chrome126: true,
          node20_0: false,
          node21_0: false,
          node22_0: true,
          firefox115: false,
          firefox117: false,
          firefox118: false,
          firefox133: false,
          firefox134: true,
          safaritp: false,
          safari16_6: false,
          safari18: true,
          ie11: false,
          duktape2_0: false,
          jerryscript2_3_0: false,
          hermes0_7_0: false,
          rhino1_7_13: false,
        }
      },
      {
        name: 'Unicode 16.0',
        exec: function () {/*
        return /^\p{RGI_Emoji}$/v.test("🇨🇶");
      */},
        res: {
          ie11: false,
          chrome128: false,
          node22_0: false,
          firefox115: false,
          firefox130: false,
          firefox133: false,
          firefox134: true,
          safari17_6: false,
        }
      }
    ]
  },
  {
    name: 'ArrayBuffer.prototype.transfer',
    category: '2024 features',
    significance: 'small',
    spec: 'https://github.com/tc39/proposal-arraybuffer-transfer',
    subtests: [
      {
        name: 'ArrayBuffer.prototype.transfer()',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer/transfer',
        exec: function () {/*
          const buffer1 = new Uint8Array([1, 2]).buffer;
          const buffer2 = buffer1.transfer();
          return buffer1.byteLength === 0
            && buffer2.byteLength === 2;
        */},
        res: {
          ie11: false,
          firefox10: false,
          firefox52: false,
          firefox117: {
            val: 'flagged',
            note_id: 'firefox-arraybuffer',
            note_html: 'The feature has to be enabled via <code>javascript.options.experimental.arraybuffer_transfer</code> setting under <code>about:config</code>.'
          },
          firefox122: true,
          chrome70: false,
          chrome114: true,
          safari12: false,
          safari17_4: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'ArrayBuffer.prototype.transferToFixedLength()',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer/transferToFixedLength',
        exec: function () {/*
          const buffer1 = new Uint8Array([1, 2]).buffer;
          const buffer2 = buffer1.transferToFixedLength();
          return buffer1.byteLength === 0
            && buffer2.byteLength === 2;
        */},
        res: {
          ie11: false,
          firefox115: false,
          firefox117: {
            val: 'flagged',
            note_id: 'firefox-arraybuffer',
          },
          firefox122: true,
          chrome114: true,
          safari17_4: true,
        }
      },
      {
        name: 'ArrayBuffer.prototype.detached',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer/detached',
        exec: function () {/*
          const buffer1 = new Uint8Array([1, 2]).buffer;
          const buffer2 = buffer1.transfer();
          return buffer1.detached && !buffer2.detached;
        */},
        res: {
          ie11: false,
          firefox115: false,
          firefox117: {
            val: 'flagged',
            note_id: 'firefox-arraybuffer',
          },
          firefox122: true,
          chrome114: true,
          safari17_4: true,
        }
      },
    ]
  },
  {
    name: 'Promise.withResolvers',
    category: '2024 features',
    significance: 'tiny',
    spec: 'https://tc39.es/proposal-promise-with-resolvers/',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/withResolvers',
    exec: function () {/*
      var obj = Promise.withResolvers();
      return obj instanceof Object
        && obj.promise instanceof Promise
        && typeof obj.resolve === 'function'
        && typeof obj.reject === 'function';
    */},
    res: {
      ie11: false,
      chrome119: true,
      firefox115: false,
      firefox121: true,
      node22_0: true,
      safari17_6: true,
      safaritp: true,
    }
  },
  {
    name: 'Array Grouping',
    category: '2024 features',
    significance: 'small',
    spec: 'https://github.com/tc39/proposal-array-grouping',
    subtests: [
      {
        name: 'Object.groupBy()',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/groupBy',
        exec: function () {/*
          const array = [1, 2, 3, 4];
          const obj = Object.groupBy(array, (num, index) => {
            return num % 2 === 0 ? 'even': 'odd';
          });
          return !('toString' in obj) && obj.even[0] == 2 && obj.odd[0] == 1;
        */},
        res: {
          ie11: false,
          chrome117: true,
          firefox97: false,
          firefox98: {
            val: 'flagged',
            note_id: 'ff-array-grouping',
            note_html: 'The feature is only available on Nightly builds, and has to be enabled via <code>javascript.options.experimental.array_grouping</code> setting under <code>about:config</code>.'
          },
          firefox119: true,
          safari17_4: true,
        }
      },
      {
        name: 'Map.groupBy()',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map/groupBy',
        exec: function () {/*
          const array = [1, 2, 3, 4];
          const odd  = { odd: true };
          const even = { even: true };
          const map = Map.groupBy(array, (num, index) => {
            return num % 2 === 0 ? even: odd;
          });
          return map instanceof Map && map.get(even)[0] === 2 && map.get(odd)[0] === 1;
        */},
        res: {
          ie11: false,
          chrome117: true,
          firefox97: false,
          firefox98: {
            val: 'flagged',
            note_id: 'ff-array-grouping',
          },
          firefox119: true,
          safari17_4: true,
        }
      },
    ]
  },
  {
    name: 'Duplicate named capturing groups',
    category: '2025 features',
    significance: 'tiny',
    spec: 'https://github.com/tc39/proposal-duplicate-named-capturing-groups',
    exec: function () {/*
    return /(?<year>[0-9]{4})-[0-9]{2}|[0-9]{2}-(?<year>[0-9]{4})/.test("12-1995");
    */},
    res: {
      chrome123: false,
      chrome126: true,
      deno1_42: false,
      node21_0: false,
      firefox115: false,
      firefox128: false,
      firefox129: true,
      safari17_4: true,
      safaritp: true,
      ie11: false,
      duktape2_0: false,
      jerryscript2_3_0: false,
      hermes0_7_0: false,
      rhino1_7_13: false,
    }
  },
  {
    name: 'Set methods',
    category: '2025 features',
    significance: 'medium',
    spec: 'https://github.com/tc39/proposal-set-methods',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set#instance_methods',
    subtests: [
      {
        name: 'Set.prototype.intersection()',
        exec: function () {/*
          var set = new Set([1, 2, 3]).intersection(new Set([2, 3, 4]));
          return set.size === 2
            && set.has(2)
            && set.has(3);
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox2: false,
          firefox117: false,
          firefox118: {
            val: 'flagged',
            note_id: 'ff-new-set-methods',
            note_html: 'The feature has to be enabled via <code>javascript.options.experimental.new_set_methods</code> setting under <code>about:config</code>.'
          },
          firefox127: true,
          chrome77: false,
          chrome122: true,
          safari17: true,
          duktape2_0: false,
          graalvm19: false,
          graalvm21_3_3: graalvm.newSetMethodsFlag,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Set.prototype.union()',
        exec: function () {/*
          var set = new Set([1, 2]).union(new Set([2, 3]));
          return set.size === 3
            && set.has(1)
            && set.has(2)
            && set.has(3);
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox2: false,
          firefox117: false,
          firefox118: {
            val: 'flagged',
            note_id: 'ff-new-set-methods'
          },
          firefox127: true,
          chrome77: false,
          chrome122: true,
          safari17: true,
          duktape2_0: false,
          graalvm19: false,
          graalvm21_3_3: graalvm.newSetMethodsFlag,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Set.prototype.difference()',
        exec: function () {/*
          var set = new Set([1, 2, 3]).difference(new Set([3, 4]));
          return set.size === 2
            && set.has(1)
            && set.has(2);
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox2: false,
          firefox117: false,
          firefox118: {
            val: 'flagged',
            note_id: 'ff-new-set-methods'
          },
          firefox127: true,
          chrome77: false,
          chrome122: true,
          safari17: true,
          duktape2_0: false,
          graalvm19: false,
          graalvm21_3_3: graalvm.newSetMethodsFlag,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Set.prototype.symmetricDifference()',
        exec: function () {/*
          var set = new Set([1, 2]).symmetricDifference(new Set([2, 3]));
          return set.size === 2
            && set.has(1)
            && set.has(3);
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox2: false,
          firefox117: false,
          firefox118: {
            val: 'flagged',
            note_id: 'ff-new-set-methods'
          },
          firefox127: true,
          chrome77: false,
          chrome122: true,
          safari17: true,
          duktape2_0: false,
          graalvm19: false,
          graalvm21_3_3: graalvm.newSetMethodsFlag,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Set.prototype.isDisjointFrom()',
        exec: function () {/*
          return new Set([1, 2, 3]).isDisjointFrom(new Set([4, 5, 6]));
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox2: false,
          firefox117: false,
          firefox118: {
            val: 'flagged',
            note_id: 'ff-new-set-methods'
          },
          firefox127: true,
          chrome77: false,
          chrome122: true,
          safari17: true,
          duktape2_0: false,
          graalvm19: false,
          graalvm20_1: graalvm.es2021flag,
          graalvm21_3_3: graalvm.newSetMethodsFlag,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Set.prototype.isSubsetOf()',
        exec: function () {/*
          return new Set([1, 2, 3]).isSubsetOf(new Set([5, 4, 3, 2, 1]));
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox2: false,
          firefox117: false,
          firefox118: {
            val: 'flagged',
            note_id: 'ff-new-set-methods'
          },
          firefox127: true,
          chrome77: false,
          chrome122: true,
          safari17: true,
          duktape2_0: false,
          graalvm19: false,
          graalvm21_3_3: graalvm.newSetMethodsFlag,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Set.prototype.isSupersetOf()',
        exec: function () {/*
          return new Set([5, 4, 3, 2, 1]).isSupersetOf(new Set([1, 2, 3]));
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox2: false,
          firefox117: false,
          firefox118: {
            val: 'flagged',
            note_id: 'ff-new-set-methods'
          },
          firefox127: true,
          chrome77: false,
          chrome122: true,
          safari17: true,
          duktape2_0: false,
          graalvm19: false,
          graalvm21_3_3: graalvm.newSetMethodsFlag,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      }
    ]
  },
  {
    name: 'RegExp Pattern Modifiers',
    category: '2025 features',
    significance: 'medium',
    spec: 'https://github.com/tc39/proposal-regexp-modifiers',
    subtests: [
      {
        name: 'i flag',
        exec: function () {/*
          const regex = /^[a-z](?-i:[a-z])$/i;
          return regex.test("ab") && regex.test("Ab") && !regex.test("aB");
        */},
        res: {
          chrome121: false,
          chrome122: chrome.harmony,
          chrome124: chrome.harmony,
          chrome125: true,
          firefox127: false,
          firefox129: false,
          firefox130: {
            val: 'flagged',
            note_id: 'ff-regexp-modidiers',
            note_html: 'The feature has to be enabled via <code>javascript.options.experimental.regexp_modifiers</code> setting under <code>about:config</code>.'
          },
          firefox132: true,
          safari17_5: false,
        }
      },
      {
        name: 'm flag',
        exec: function () {/*
          const regex = /^a|(?m:^b)/;
          return regex.test("a") && regex.test("b") && regex.test("c\nb") && !regex.test("c\na");
        */},
        res: {
          chrome121: false,
          chrome122: chrome.harmony,
          chrome124: chrome.harmony,
          chrome125: true,
          firefox127: false,
          firefox129: false,
          firefox130: {
            val: 'flagged',
            note_id: 'ff-regexp-modidiers',
          },
          firefox132: true,
          safari17_5: false,
        }
      },
      {
        name: 's flag',
        exec: function () {/*
          const regex = /.(?-s:.)/s;
          return regex.test("\na") && regex.test("aa") && !regex.test("\n\n");
        */},
        res: {
          chrome121: false,
          chrome122: chrome.harmony,
          chrome124: chrome.harmony,
          chrome125: true,
          firefox127: false,
          firefox129: false,
          firefox130: {
            val: 'flagged',
            note_id: 'ff-regexp-modidiers',
          },
          firefox132: true,
          safari17_5: false,
        }
      },
    ]
  },
  {
    name: 'Iterator Helpers',
    category: '2025 features',
    significance: 'large',
    spec: 'https://github.com/tc39/proposal-iterator-helpers',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helpers',
    subtests: [
      {
        name: 'instanceof Iterator',
        exec: function () {/*
          return [1, 2, 3].values() instanceof Iterator;
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox10: false,
          firefox60: false,
          firefox116: false,
          firefox117: {
            val: 'flagged',
            note_id: 'ff-iterator-helpers',
            note_html: 'The feature is only available on Nightly builds, and has to be enabled via <code>javascript.options.experimental.iterator_helpers</code> setting under <code>about:config</code>.'
          },
          firefox131: true,
          chrome77: false,
          chrome126: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'extends Iterator',
        exec: function () {/*
          class Class extends Iterator { }
          const instance = new Class();
          return instance[Symbol.iterator]() === instance;
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox10: false,
          firefox60: false,
          firefox116: false,
          firefox117: {
            val: 'flagged',
            note_id: 'ff-iterator-helpers'
          },
          firefox131: true,
          chrome77: false,
          chrome126: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Iterator.from, iterable',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator/from',
        exec: function () {/*
          const iterator = Iterator.from([1, 2, 3]);
          return 'next' in iterator
            && iterator instanceof Iterator
            && Array.from(iterator).join() === '1,2,3';
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox10: false,
          firefox60: false,
          firefox116: false,
          firefox117: {
            val: 'flagged',
            note_id: 'ff-iterator-helpers'
          },
          firefox131: true,
          chrome77: false,
          chrome126: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Iterator.from, iterator',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator/from',
        exec: function () {/*
          const iterator = Iterator.from({
            i: 0,
            next() {
              return { value: ++this.i, done: this.i > 3 };
            }
          });
          return 'next' in iterator
            && iterator instanceof Iterator
            && Array.from(iterator).join() === '1,2,3';
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox10: false,
          firefox60: false,
          firefox116: false,
          firefox117: {
            val: 'flagged',
            note_id: 'ff-iterator-helpers'
          },
          firefox131: true,
          chrome77: false,
          chrome126: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Iterator.prototype.drop',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator/drop',
        exec: function () {/*
          return Array.from([1, 2, 3].values().drop(1)).join() === '2,3';
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox10: false,
          firefox60: false,
          firefox116: false,
          firefox117: {
            val: 'flagged',
            note_id: 'ff-iterator-helpers'
          },
          firefox131: true,
          chrome77: false,
          chrome126: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Iterator.prototype.every',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator/every',
        exec: function () {/*
          return [1, 2, 3].values().every(it => typeof it === 'number');
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox10: false,
          firefox60: false,
          firefox116: false,
          firefox117: {
            val: 'flagged',
            note_id: 'ff-iterator-helpers'
          },
          firefox131: true,
          chrome77: false,
          chrome126: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Iterator.prototype.filter',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator/filter',
        exec: function () {/*
          return Array.from([1, 2, 3].values().filter(it => it % 2)).join() === '1,3';
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox10: false,
          firefox60: false,
          firefox116: false,
          firefox117: {
            val: 'flagged',
            note_id: 'ff-iterator-helpers'
          },
          firefox131: true,
          chrome77: false,
          chrome126: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Iterator.prototype.find',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator/find',
        exec: function () {/*
          return [1, 2, 3].values().find(it => it % 2) === 1;
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox10: false,
          firefox60: false,
          firefox116: false,
          firefox117: {
            val: 'flagged',
            note_id: 'ff-iterator-helpers'
          },
          firefox131: true,
          chrome77: false,
          chrome126: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Iterator.prototype.flatMap',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator/flatMap',
        exec: function () {/*
          return Array.from([1, 2, 3].values().flatMap(it => [it, 0])).join() === '1,0,2,0,3,0';
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox10: false,
          firefox60: false,
          firefox116: false,
          firefox117: {
            val: 'flagged',
            note_id: 'ff-iterator-helpers'
          },
          firefox131: true,
          chrome77: false,
          chrome126: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Iterator.prototype.forEach',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator/forEach',
        exec: function () {/*
          let result = '';
          [1, 2, 3].values().forEach(it => result += it);
          return result === '123';
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox10: false,
          firefox60: false,
          firefox116: false,
          firefox117: {
            val: 'flagged',
            note_id: 'ff-iterator-helpers'
          },
          firefox131: true,
          chrome77: false,
          chrome126: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Iterator.prototype.map',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator/map',
        exec: function () {/*
          return Array.from([1, 2, 3].values().map(it => it * it)).join() === '1,4,9';
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox10: false,
          firefox60: false,
          firefox116: false,
          firefox117: {
            val: 'flagged',
            note_id: 'ff-iterator-helpers'
          },
          firefox131: true,
          chrome77: false,
          chrome126: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Iterator.prototype.reduce',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator/reduce',
        exec: function () {/*
          return [1, 2, 3].values().reduce((a, b) => a + b) === 6;
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox10: false,
          firefox60: false,
          firefox116: false,
          firefox117: {
            val: 'flagged',
            note_id: 'ff-iterator-helpers'
          },
          firefox131: true,
          chrome77: false,
          chrome126: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Iterator.prototype.some',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator/some',
        exec: function () {/*
          return [1, 2, 3].values().some(it => typeof it === 'number');
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox10: false,
          firefox60: false,
          firefox116: false,
          firefox117: {
            val: 'flagged',
            note_id: 'ff-iterator-helpers'
          },
          firefox131: true,
          chrome77: false,
          chrome126: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Iterator.prototype.take',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator/take',
        exec: function () {/*
          return Array.from([1, 2, 3].values().take(2)).join() === '1,2';
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox10: false,
          firefox60: false,
          firefox116: false,
          firefox117: {
            val: 'flagged',
            note_id: 'ff-iterator-helpers'
          },
          firefox131: true,
          chrome77: false,
          chrome126: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Iterator.prototype.toArray',
        mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator/toArray',
        exec: function () {/*
          const array = [1, 2, 3].values().toArray();
          return Array.isArray(array) && array.join() === '1,2,3';
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox10: false,
          firefox60: false,
          firefox116: false,
          firefox117: {
            val: 'flagged',
            note_id: 'ff-iterator-helpers'
          },
          firefox131: true,
          chrome77: false,
          chrome126: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
      {
        name: 'Iterator.prototype[@@toStringTag]',
        exec: function () {/*
          return Iterator.prototype[Symbol.toStringTag] === 'Iterator';
        */},
        res: {
          babel6corejs2: false,
          babel7corejs3: babel.corejs,
          typescript1corejs2: typescript.fallthrough,
          typescript3_2corejs3: typescript.corejs,
          ie11: false,
          firefox10: false,
          firefox60: false,
          firefox116: false,
          firefox117: {
            val: 'flagged',
            note_id: 'ff-iterator-helpers'
          },
          firefox131: true,
          chrome77: false,
          chrome126: true,
          duktape2_0: false,
          graalvm21_3_3: false,
          hermes0_7_0: false,
          reactnative0_70_3: false,
          rhino1_7_13: false
        }
      },
    ]
  },
  {
    name: 'Promise.try',
    category: '2025 features',
    significance: 'tiny',
    spec: 'https://github.com/tc39/proposal-promise-try',
    mdn: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/try',
    exec: function () {/*
      var called = false;
      var argsMatch = false;
      var p = Promise.try(function () { called = true; })
      var p2 = Promise.try(function () {
        'use strict';
        argsMatch = this === undefined && arguments.length === 2 && args[0] === p && args[1] === 2;
      }, [p, 2]);

      return p instanceof Promise && called && argsMatch;
    */},
    res: {
      ie11: false,
      chrome128: true,
      firefox115: false,
      firefox131: false,
      firefox132: {
        val: 'flagged',
        note_id: 'ff-promise-try',
        note_html: 'The feature is only available on Nightly builds, and has to be enabled via <code>javascript.options.experimental.promise_try</code> setting under <code>about:config</code>.'
      },
      firefox134: true,
      node23: true,
    }
  }
];

//Shift annex B features to the bottom
exports.tests = exports.tests.reduce(function (a, e) {
  var index = ['2016 features', '2016 misc', '2017 features', '2017 misc', '2017 annex b', '2018 features', '2018 misc', '2019 features', '2019 misc', '2020 features', '2021 features', '2022 features', '2023 features', '2024 features', '2025 features', 'finished (stage 4)'].indexOf(e.category);
  if (index === -1) {
    console.log('"' + a.category + '" is not an ES2016+ category!');
  }
  (a[index] = a[index] || []).push(e);
  return a;
},[]).reduce(function (a, e) {
  return a.concat(e);
},[]);