array-elem-trlg-iter-elision-iter-nrml-close-null.js (2023B)
1 // This file was procedurally generated from the following sources: 2 // - src/dstr-assignment/array-elem-trlg-iter-elision-iter-nrml-close-null.case 3 // - src/dstr-assignment/error/assignment-expr.template 4 /*--- 5 description: IteratorClose throws a TypeError when `return` returns a non-Object value (AssignmentExpression) 6 esid: sec-variable-statement-runtime-semantics-evaluation 7 features: [Symbol.iterator, destructuring-binding] 8 flags: [generated] 9 info: | 10 VariableDeclaration : BindingPattern Initializer 11 12 1. Let rhs be the result of evaluating Initializer. 13 2. Let rval be GetValue(rhs). 14 3. ReturnIfAbrupt(rval). 15 4. Return the result of performing BindingInitialization for 16 BindingPattern passing rval and undefined as arguments. 17 18 ArrayAssignmentPattern : 19 [ AssignmentElementList , Elisionopt AssignmentRestElementopt ] 20 21 [...] 22 6. If Elision is present, then 23 a. Let status be the result of performing 24 IteratorDestructuringAssignmentEvaluation of Elision with 25 iteratorRecord as the argument. 26 b. If status is an abrupt completion, then 27 [...] 28 8. If iteratorRecord.[[done]] is false, return IteratorClose(iterator, 29 status). 30 31 7.4.6 IteratorClose( iterator, completion ) 32 33 [...] 34 6. Let innerResult be Call(return, iterator, « »). 35 7. If completion.[[type]] is throw, return Completion(completion). 36 8. If innerResult.[[type]] is throw, return Completion(innerResult). 37 9. If Type(innerResult.[[value]]) is not Object, throw a TypeError 38 exception. 39 40 ---*/ 41 var iterable = {}; 42 var x; 43 var nextCount = 0; 44 var iterator = { 45 next: function() { 46 nextCount += 1; 47 // Set an upper-bound to limit unnecessary iteration in non-conformant 48 // implementations 49 return { done: nextCount > 10 }; 50 }, 51 return: function() { 52 return null; 53 } 54 }; 55 iterable[Symbol.iterator] = function() { 56 return iterator; 57 }; 58 59 assert.throws(TypeError, function() { 60 0, [ x , , ] = iterable; 61 }); 62 63 reportCompare(0, 0);