| // Copyright (C) 2016 the V8 project authors. All rights reserved. |
| // This code is governed by the BSD license found in the LICENSE file. |
| /*--- |
| esid: sec-generator-function-definitions-runtime-semantics-evaluation |
| es6id: 14.4.14 |
| description: > |
| `value` property is not accessed when iteration is incomplete |
| info: | |
| YieldExpression : yield * AssignmentExpression |
| |
| 1. Let exprRef be the result of evaluating AssignmentExpression. |
| 2. Let value be ? GetValue(exprRef). |
| 3. Let iterator be ? GetIterator(value). |
| 4. Let received be NormalCompletion(undefined). |
| 5. Repeat |
| a. If received.[[Type]] is normal, then |
| [...] |
| b. Else if received.[[Type]] is throw, then |
| [...] |
| c. Else, |
| i. Assert: received.[[Type]] is return. |
| ii. Let return be ? GetMethod(iterator, "return"). |
| iii. If return is undefined, return Completion(received). |
| iv. Let innerReturnResult be ? Call(return, iterator, « |
| received.[[Value]] »). |
| v. If Type(innerReturnResult) is not Object, throw a TypeError |
| exception. |
| vi. Let done be ? IteratorComplete(innerReturnResult). |
| vii. If done is true, then |
| 1. Let value be ? IteratorValue(innerReturnResult). |
| 2. Return Completion{[[Type]]: return, [[Value]]: value, |
| [[Target]]: empty}. |
| viii. Let received be GeneratorYield(innerReturnResult). |
| |
| 7.4.3 IteratorComplete |
| |
| 1. Assert: Type(iterResult) is Object. |
| 2. Return ToBoolean(? Get(iterResult, "done")). |
| features: [generators, Symbol.iterator] |
| ---*/ |
| |
| var badIter = {}; |
| var callCount = 0; |
| var spyValue = Object.defineProperty({ done: false }, 'value', { |
| get: function() { |
| callCount += 1; |
| } |
| }); |
| badIter[Symbol.iterator] = function() { |
| return { |
| next: function() { |
| return { done: false }; |
| }, |
| return: function() { |
| return spyValue; |
| } |
| }; |
| }; |
| var normalCompletion = false; |
| var errorCompletion = false; |
| var delegationComplete = false; |
| function* g() { |
| try { |
| yield * badIter; |
| normalCompletion = true; |
| } catch (_) { |
| errorCompletion = true; |
| } finally { |
| delegationComplete = true; |
| } |
| } |
| var iter = g(); |
| |
| iter.next(); |
| assert.sameValue(callCount, 0, 'access count (first iteration)'); |
| assert.sameValue( |
| delegationComplete, false, 'delegation ongoing (first iteration)' |
| ); |
| |
| iter.return(); |
| assert.sameValue(callCount, 0, 'access count (second iteration)'); |
| assert.sameValue( |
| delegationComplete, false, 'delegation ongoing (second iteration)' |
| ); |
| |
| spyValue.done = true; |
| iter.return(); |
| assert.sameValue(callCount, 1, 'access count (final iteration)'); |
| assert.sameValue(delegationComplete, true, 'delegation complete'); |
| assert.sameValue(normalCompletion, false, 'completion was abrupt'); |
| assert.sameValue(errorCompletion, false, 'completion was not of type "throw"'); |