fix TLA with esnext syntax

brigand · Aug 23, 2019 · d7f048e · d7f048e
1 parent d13d8bf
commit d7f048e
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Showing 3 changed files with 94 additions and 67 deletions.
diff --git a/package.json b/package.json
@@ -6,13 +6,13 @@
   "repository": "[email protected]:brigand/jellobot.git",
   "author": "Frankie Bagnardi <[email protected]>",
   "license": "MIT",
-
   "scripts": {
     "test": "jest",
     "update-engine262": "dir='src/plugins/js-eval/vendor'; mkdir -p \"$dir\" && cd \"$dir\" && curl -sS https://engine262.js.org/engine262.js > engine262.js && node --check ./engine262"
   },
   "dependencies": {
     "@babel/core": "^7.5.5",
+    "@babel/generator": "^7.5.5",
     "@babel/parser": "^7.5.5",
     "@babel/plugin-proposal-class-properties": "^7.1.0",
     "@babel/plugin-proposal-decorators": "^7.4.4",
@@ -35,6 +35,7 @@
     "@babel/plugin-syntax-import-meta": "^7.0.0",
     "@babel/plugin-transform-modules-commonjs": "^7.5.0",
     "@babel/plugin-transform-typescript": "^7.5.5",
+    "@babel/traverse": "^7.5.5",
     "bluebird": "^3.5.2",
     "chalk": "^2.4.1",
     "cheerio": "^0.22.0",
@@ -45,7 +46,6 @@
     "json5": "^2.1.0",
     "node-fetch": "^2.3.0",
     "prettier": "^1.14.3",
-    "recast": "^0.18.1",
     "shell-escape": "^0.2.0",
     "superagent": "^3.8.3"
   },

diff --git a/src/plugins/js-eval/jsEvalPlugin.js b/src/plugins/js-eval/jsEvalPlugin.js
@@ -10,42 +10,44 @@ const CMD = ['node', '--no-warnings', '/run/run.js'];
 const CMD_SHIMS = ['node', '-r', '/run/node_modules/airbnb-js-shims/target/es2019', '/run/run.js'];
 const CMD_HARMONY = ['node', '--harmony', '--experimental-vm-modules', '--experimental-modules', '--no-warnings', '/run/run.js'];
 
+const babelTransformOpts = {
+  parserOpts: {
+    allowAwaitOutsideFunction: true,
+    allowReturnOutsideFunction: true,
+  },
+  plugins: [
+    '@babel/plugin-transform-typescript',
+    '@babel/plugin-transform-modules-commonjs', // required by dynamicImport
+    ['@babel/plugin-proposal-decorators', { decoratorsBeforeExport: false }], // must be before class-properties https://babeljs.io/docs/en/babel-plugin-proposal-decorators#note-compatibility-with-babel-plugin-proposal-class-properties
+    '@babel/plugin-proposal-class-properties',
+    '@babel/plugin-proposal-do-expressions',
+    '@babel/plugin-proposal-export-default-from',
+    '@babel/plugin-proposal-export-namespace-from',
+    '@babel/plugin-proposal-function-sent',
+    '@babel/plugin-proposal-function-bind',
+    '@babel/plugin-proposal-json-strings',
+    '@babel/plugin-proposal-logical-assignment-operators',
+    '@babel/plugin-proposal-nullish-coalescing-operator',
+    '@babel/plugin-proposal-numeric-separator',
+    '@babel/plugin-proposal-optional-catch-binding',
+    '@babel/plugin-proposal-optional-chaining',
+    '@babel/plugin-proposal-partial-application',
+    ['@babel/plugin-proposal-pipeline-operator', { proposal: 'minimal' }],
+    '@babel/plugin-proposal-throw-expressions',
+    '@babel/plugin-proposal-dynamic-import',
+    '@babel/plugin-syntax-bigint',
+    '@babel/plugin-syntax-import-meta',
+  ]
+};
+
 const jsEvalPlugin = async ({ mentionUser, respond, message, selfConfig = {} }) => {
   if (!/^[nhbsme?]>/.test(message)) return;
   const mode = message[0];
   if (mode === '?') return respond((mentionUser ? `${mentionUser}, ` : '') + helpMsg);
   let code = message.slice(2);
 
   if (mode === 'b') {
-    code = (await babel.transformAsync(code, {
-      parserOpts: {
-        allowAwaitOutsideFunction: true,
-        allowReturnOutsideFunction: true,
-      },
-      plugins: [
-        '@babel/plugin-transform-typescript',
-        '@babel/plugin-transform-modules-commonjs', // required by dynamicImport
-        ['@babel/plugin-proposal-decorators', { decoratorsBeforeExport: false }], // must be before class-properties https://babeljs.io/docs/en/babel-plugin-proposal-decorators#note-compatibility-with-babel-plugin-proposal-class-properties
-        '@babel/plugin-proposal-class-properties',
-        '@babel/plugin-proposal-do-expressions',
-        '@babel/plugin-proposal-export-default-from',
-        '@babel/plugin-proposal-export-namespace-from',
-        '@babel/plugin-proposal-function-sent',
-        '@babel/plugin-proposal-function-bind',
-        '@babel/plugin-proposal-json-strings',
-        '@babel/plugin-proposal-logical-assignment-operators',
-        '@babel/plugin-proposal-nullish-coalescing-operator',
-        '@babel/plugin-proposal-numeric-separator',
-        '@babel/plugin-proposal-optional-catch-binding',
-        '@babel/plugin-proposal-optional-chaining',
-        '@babel/plugin-proposal-partial-application',
-        ['@babel/plugin-proposal-pipeline-operator', { proposal: 'minimal' }],
-        '@babel/plugin-proposal-throw-expressions',
-        '@babel/plugin-proposal-dynamic-import',
-        '@babel/plugin-syntax-bigint',
-        '@babel/plugin-syntax-import-meta',
-      ]
-    })).code;
+    code = (await babel.transformAsync(code, babelTransformOpts)).code;
   }
 
   code = processTopLevelAwait(code) || code; // it returns null when no TLA is found

diff --git a/src/plugins/js-eval/processTopLevelAwait.js b/src/plugins/js-eval/processTopLevelAwait.js
@@ -1,53 +1,72 @@
 const babelParser = require('@babel/parser');
-const recast = require('recast');
+const babelTraverse = require('@babel/traverse').default;
+const babelGenerator = require('@babel/generator').default;
+
+const babelParseOpts = {
+  allowAwaitOutsideFunction: true,
+  plugins: [
+    'throwExpressions',
+    'bigInt',
+    ['decorators', { decoratorsBeforeExport: true }],
+    'classProperties',
+    'classPrivateProperties',
+    'classPrivateMethods',
+    'doExpressions',
+    'dynamicImport',
+    'exportDefaultFrom',
+    'exportNamespaceFrom',
+    'functionBind',
+    'functionSent',
+    'importMeta',
+    'logicalAssignment',
+    'nullishCoalescingOperator',
+    'numericSeparator',
+    // 'objectRestSpread',
+    'optionalCatchBinding',
+    'optionalChaining',
+    'partialApplication',
+    ['pipelineOperator', { proposal: 'minimal' }],
+    'throwExpressions'
+  ]
+};
 
-const b = recast.types.builders;
 
 function processTopLevelAwait(src) {
   let root;
 
   try {
-    root = recast.parse(src, {
-      parser: {
-        parse(src) {
-          return babelParser.parse(src, { allowAwaitOutsideFunction: true });
-        }
-      }
-    });
+    root = babelParser.parse(src, babelParseOpts);
   } catch (error) {
     return null; // if code is not valid, don't bother
   }
 
   let containsAwait = false;
   let containsReturn = false;
 
-  recast.visit(root, {
-    visitNode: function (path) {
-      const node = path.value;
-
-      switch (node.type) {
+  babelTraverse(root, {
+    enter(path) {
+      switch (path.type) {
+        case 'FunctionDeclaration':
         case 'FunctionExpression':
         case 'ArrowFunctionExpression':
         case 'MethodDefinition':
+        case 'ClassMethod':
           // stop when entering a new function scope:
-          return false;
+          return path.stop();
 
         case 'ForOfStatement':
-          if (node.await === true) {
+          if (path.node.await === true) {
             containsAwait = true;
           }
-          return this.traverse(path);
+          return;
 
         case 'AwaitExpression':
           containsAwait = true;
-          return this.traverse(path);
+          return;
 
         case 'ReturnStatement':
           containsReturn = true;
-          return this.traverse(path);
-
-        default:
-          return this.traverse(path);
+          return;
       }
     }
   });
@@ -65,20 +84,26 @@ function processTopLevelAwait(src) {
   }
 
   // replace last node with a returnStatement of this node
-  root.program.body[root.program.body.length - 1] = b.returnStatement(last);
-
-  const iiafe = b.callExpression(
-    b.arrowFunctionExpression(
-      [],
-      b.blockStatement(root.program.body),
-      true
-    ),
-    []
-  );
-
-  iiafe.callee.async = true;
-
-  return recast.print(iiafe).code;
+  root.program.body[root.program.body.length - 1] = {
+    type: 'ReturnStatement',
+    argument: last
+  };
+
+  const iiafe = {
+    type: 'CallExpression',
+    callee: {
+      type: 'ArrowFunctionExpression',
+      async: true,
+      params: [],
+      body: {
+        type: 'BlockStatement',
+        body: root.program.body
+      },
+    },
+    arguments: []
+  };
+
+  return babelGenerator(iiafe).code;
 }
 
 module.exports = processTopLevelAwait;