// This file was procedurally generated from the following sources: // - src/dstr-assignment/array-elem-trlg-iter-rest-rtrn-close-null.case // - src/dstr-assignment/default/for-of.template /*--- description: IteratorClose throws a TypeError when `return` returns a non-Object value (For..of statement) esid: sec-for-in-and-for-of-statements-runtime-semantics-labelledevaluation features: [Symbol.iterator, generators, destructuring-binding] flags: [generated] info: | IterationStatement : for ( LeftHandSideExpression of AssignmentExpression ) Statement 1. Let keyResult be the result of performing ? ForIn/OfHeadEvaluation(« », AssignmentExpression, iterate). 2. Return ? ForIn/OfBodyEvaluation(LeftHandSideExpression, Statement, keyResult, assignment, labelSet). 13.7.5.13 Runtime Semantics: ForIn/OfBodyEvaluation [...] 4. If destructuring is true and if lhsKind is assignment, then a. Assert: lhs is a LeftHandSideExpression. b. Let assignmentPattern be the parse of the source text corresponding to lhs using AssignmentPattern as the goal symbol. [...] ArrayAssignmentPattern : [ AssignmentElementList , Elisionopt AssignmentRestElementopt ] [...] 7. If AssignmentRestElement is present, then a. Let status be the result of performing IteratorDestructuringAssignmentEvaluation of AssignmentRestElement with iteratorRecord as the argument. 8. If iteratorRecord.[[done]] is false, return IteratorClose(iterator, status). 9. Return Completion(status). 7.4.6 IteratorClose( iterator, completion ) [...] 6. Let innerResult be Call(return, iterator, « »). 7. If completion.[[type]] is throw, return Completion(completion). 8. If innerResult.[[type]] is throw, return Completion(innerResult). ---*/ var nextCount = 0; var iterable = {}; var x; var iterator = { next: function() { nextCount += 1; // Set an upper-bound to limit unnecessary iteration in non-conformant // implementations return { done: nextCount > 10 }; }, return: function() { return null; } }; var iter; iterable[Symbol.iterator] = function() { return iterator; }; function* g() { var counter = 0; for ([ x , ...{}[yield] ] of [iterable]) { counter += 1; } assert.sameValue(counter, 1); } iter = g(); iter.next(); assert.throws(TypeError, function() { iter.return(); }); assert.sameValue(nextCount, 1); reportCompare(0, 0);