Merge pull request #1123 from zloirock/iterator-helpers

CHANGELOG.md

@@ -3,6 +3,7 @@
 - [`Array.fromAsync` proposal](https://github.com/tc39/proposal-array-from-async):
   - Moved to Stage 3, [September TC39 meeting](https://github.com/babel/proposals/issues/83#issuecomment-1246218703)
   - Avoid observable side effects of `%Array.prototype.values%` usage in array-like branch, [proposal-array-from-async/30](https://github.com/tc39/proposal-array-from-async/pull/30)
+- Early exit on broken `.next` in missed cases of `{ Iterator, AsyncIterator }.from`, [proposal-iterator-helpers/232](https://github.com/tc39/proposal-iterator-helpers/pull/232)
 - Added `inverse` option to `core-js-compat`, [#1119](https://github.com/zloirock/core-js/issues/1119)
 - Added `format` option to `core-js-builder`, [#1120](https://github.com/zloirock/core-js/issues/1120)
 

packages/core-js/internals/array-from-async.js

@@ -5,6 +5,7 @@ var toObject = require('../internals/to-object');
 var isConstructor = require('../internals/is-constructor');
 var getAsyncIterator = require('../internals/get-async-iterator');
 var getIterator = require('../internals/get-iterator');
+var getIteratorDirect = require('../internals/get-iterator-direct');
 var getIteratorMethod = require('../internals/get-iterator-method');
 var getMethod = require('../internals/get-method');
 var getVirtual = require('../internals/entry-virtual');
@@ -44,7 +45,7 @@ module.exports = function fromAsync(asyncItems /* , mapfn = undefined, thisArg =
     var A = isConstructor(C) ? new C() : [];
     var iterator = usingAsyncIterator
       ? getAsyncIterator(O, usingAsyncIterator)
-      : new AsyncFromSyncIterator(getIterator(O, usingSyncIterator));
+      : new AsyncFromSyncIterator(getIteratorDirect(getIterator(O, usingSyncIterator)));
     resolve(toArray(iterator, mapfn, A));
   });
 };

packages/core-js/internals/async-from-sync-iterator.js

@@ -22,12 +22,9 @@ var asyncFromSyncIteratorContinuation = function (result, resolve, reject) {
   }, reject);
 };
 
-var AsyncFromSyncIterator = function AsyncIterator(iterator) {
-  setInternalState(this, {
-    type: ASYNC_FROM_SYNC_ITERATOR,
-    iterator: anObject(iterator),
-    next: iterator.next
-  });
+var AsyncFromSyncIterator = function AsyncIterator(iteratorRecord) {
+  iteratorRecord.type = ASYNC_FROM_SYNC_ITERATOR;
+  setInternalState(this, iteratorRecord);
 };
 
 AsyncFromSyncIterator.prototype = defineBuiltIns(create(AsyncIteratorPrototype), {

packages/core-js/internals/get-async-iterator.js

@@ -2,12 +2,13 @@ var call = require('../internals/function-call');
 var AsyncFromSyncIterator = require('../internals/async-from-sync-iterator');
 var anObject = require('../internals/an-object');
 var getIterator = require('../internals/get-iterator');
+var getIteratorDirect = require('../internals/get-iterator-direct');
 var getMethod = require('../internals/get-method');
 var wellKnownSymbol = require('../internals/well-known-symbol');
 
 var ASYNC_ITERATOR = wellKnownSymbol('asyncIterator');
 
 module.exports = function (it, usingIterator) {
   var method = arguments.length < 2 ? getMethod(it, ASYNC_ITERATOR) : usingIterator;
-  return method ? anObject(call(method, it)) : new AsyncFromSyncIterator(getIterator(it));
+  return method ? anObject(call(method, it)) : new AsyncFromSyncIterator(getIteratorDirect(getIterator(it)));
 };

packages/core-js/modules/esnext.async-iterator.from.js

@@ -18,15 +18,17 @@ $({ target: 'AsyncIterator', stat: true, forced: true }, {
   from: function from(O) {
     var object = toObject(O);
     var usingIterator = getMethod(object, ASYNC_ITERATOR);
-    var iterator;
+    var iteratorRecord;
     if (usingIterator) {
-      iterator = getAsyncIterator(object, usingIterator);
-      if (isPrototypeOf(AsyncIteratorPrototype, iterator)) return iterator;
+      iteratorRecord = getIteratorDirect(getAsyncIterator(object, usingIterator));
+      if (isPrototypeOf(AsyncIteratorPrototype, iteratorRecord.iterator)) return iteratorRecord.iterator;
     }
-    if (iterator === undefined) {
+    if (iteratorRecord === undefined) {
       usingIterator = getIteratorMethod(object);
-      if (usingIterator) iterator = new AsyncFromSyncIterator(getIterator(object, usingIterator));
+      if (usingIterator) iteratorRecord = getIteratorDirect(new AsyncFromSyncIterator(
+        getIteratorDirect(getIterator(object, usingIterator))
+      ));
     }
-    return new WrapAsyncIterator(getIteratorDirect(iterator !== undefined ? iterator : object));
+    return new WrapAsyncIterator(iteratorRecord !== undefined ? iteratorRecord : getIteratorDirect(object));
   }
 });

packages/core-js/modules/esnext.iterator.from.js

@@ -17,12 +17,12 @@ $({ target: 'Iterator', stat: true, forced: true }, {
   from: function from(O) {
     var object = toObject(O);
     var usingIterator = getIteratorMethod(object);
-    var iterator;
+    var iteratorRecord;
     if (usingIterator) {
-      iterator = getIterator(object, usingIterator);
-      if (isPrototypeOf(IteratorPrototype, iterator)) return iterator;
+      iteratorRecord = getIteratorDirect(getIterator(object, usingIterator));
+      if (isPrototypeOf(IteratorPrototype, iteratorRecord.iterator)) return iteratorRecord.iterator;
     } else {
-      iterator = object;
-    } return new IteratorProxy(getIteratorDirect(iterator));
+      iteratorRecord = getIteratorDirect(object);
+    } return new IteratorProxy(iteratorRecord);
   }
 });

packages/core-js/modules/esnext.iterator.to-async.js

@@ -7,6 +7,6 @@ var getIteratorDirect = require('../internals/get-iterator-direct');
 
 $({ target: 'Iterator', proto: true, real: true, forced: true }, {
   toAsync: function toAsync() {
-    return new WrapAsyncIterator(getIteratorDirect(new AsyncFromSyncIterator(this)));
+    return new WrapAsyncIterator(getIteratorDirect(new AsyncFromSyncIterator(getIteratorDirect(this))));
   }
 });

tests/pure/esnext.async-iterator.from.js

@@ -4,7 +4,7 @@ import values from 'core-js-pure/es/array/values';
 import AsyncIterator from 'core-js-pure/full/async-iterator';
 
 QUnit.test('AsyncIterator.from', assert => {
-  assert.expect(9);
+  assert.expect(10);
   const async = assert.async();
   const { from } = AsyncIterator;
 
@@ -29,4 +29,5 @@ QUnit.test('AsyncIterator.from', assert => {
   assert.throws(() => from(undefined), TypeError);
   assert.throws(() => from(null), TypeError);
   assert.throws(() => from({}), TypeError);
+  assert.throws(() => from(assign(new AsyncIterator(), { next: 42 })), TypeError);
 });

tests/pure/esnext.iterator.from.js

@@ -1,6 +1,7 @@
 import { createIterable, createIterator } from '../helpers/helpers';
 
 import Iterator from 'core-js-pure/full/iterator';
+import assign from 'core-js-pure/es/object/assign';
 
 QUnit.test('Iterator.from', assert => {
   const { from } = Iterator;
@@ -17,4 +18,5 @@ QUnit.test('Iterator.from', assert => {
   assert.throws(() => from(undefined), TypeError);
   assert.throws(() => from(null), TypeError);
   assert.throws(() => from({}), TypeError);
+  assert.throws(() => from(assign(new Iterator(), { next: 42 })), TypeError);
 });

tests/tests/esnext.async-iterator.from.js

@@ -1,5 +1,7 @@
+const { assign } = Object;
+
 QUnit.test('AsyncIterator.from', assert => {
-  assert.expect(12);
+  assert.expect(13);
   const async = assert.async();
   const { from } = AsyncIterator;
 
@@ -18,7 +20,7 @@ QUnit.test('AsyncIterator.from', assert => {
     async();
   });
 
-  const asyncIterator = Object.assign(new AsyncIterator(), {
+  const asyncIterator = assign(new AsyncIterator(), {
     next: () => { /* empty */ },
   });
 
@@ -27,4 +29,5 @@ QUnit.test('AsyncIterator.from', assert => {
   assert.throws(() => from(undefined), TypeError);
   assert.throws(() => from(null), TypeError);
   assert.throws(() => from({}), TypeError);
+  assert.throws(() => from(assign(new AsyncIterator(), { next: 42 })), TypeError);
 });

tests/tests/esnext.iterator.from.js

@@ -1,5 +1,7 @@
 import { createIterable, createIterator } from '../helpers/helpers';
 
+const { assign } = Object;
+
 QUnit.test('Iterator.from', assert => {
   const { from } = Iterator;
 
@@ -18,4 +20,5 @@ QUnit.test('Iterator.from', assert => {
   assert.throws(() => from(undefined), TypeError);
   assert.throws(() => from(null), TypeError);
   assert.throws(() => from({}), TypeError);
+  assert.throws(() => from(assign(new Iterator(), { next: 42 })), TypeError);
 });