// 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: Abrupt completion returned when accessing iterator `return` method 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"). features: [generators, Symbol.iterator] ---*/ var thrown = new Test262Error(); var badIter = {}; var callCount = 0; var poisonedReturn = { next: function() { return { done: false }; } }; Object.defineProperty(poisonedReturn, 'throw', { get: function() { callCount += 1; } }); Object.defineProperty(poisonedReturn, 'return', { get: function() { throw thrown; } }); badIter[Symbol.iterator] = function() { return poisonedReturn; }; function* g() { try { yield * badIter; } catch (err) { caught = err; } } var iter = g(); var result, caught; iter.next(); assert.sameValue(caught, undefined, '`return` property not accessed eagerly'); result = iter.return(); assert.sameValue(result.value, undefined); assert.sameValue(result.done, true); assert.sameValue(caught, thrown); assert.sameValue(callCount, 0, 'iterator `throw` property is not accessed'); reportCompare(0, 0);