// 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 i. Let innerResult be ? IteratorNext(iterator, received.[[Value]]). ii. Let done be ? IteratorComplete(innerResult). iii. If done is true, then 1. Return ? IteratorValue(innerResult). 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 spyValue; } }; }; var delegationComplete = false; function* g() { yield * badIter; delegationComplete = true; } var iter = g(); iter.next(); assert.sameValue(callCount, 0, 'access count (first iteration)'); assert.sameValue( delegationComplete, false, 'delegation ongoing (first iteration)' ); iter.next(); assert.sameValue(callCount, 0, 'access count (second iteration)'); assert.sameValue( delegationComplete, false, 'delegation ongoing (second iteration)' ); spyValue.done = true; iter.next(); assert.sameValue(callCount, 1, 'access count (final iteration)'); assert.sameValue(delegationComplete, true, 'delegation complete'); reportCompare(0, 0);