tor-browser

The Tor Browser
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async-gen-decl-dstr-array-empty-iter-close.js (2332B)

      1 // |reftest| async
      2 // This file was procedurally generated from the following sources:
      3 // - src/dstr-assignment-for-await/array-empty-iter-close.case
      4 // - src/dstr-assignment-for-await/async-generator/async-gen-decl.template
      5 /*---
      6 description: Iterator is closed without iterating (for-await-of statement in an async generator declaration)
      7 esid: sec-for-in-and-for-of-statements-runtime-semantics-labelledevaluation
      8 features: [Symbol.iterator, destructuring-binding, async-iteration]
      9 flags: [generated, async]
     10 info: |
     11    IterationStatement :
     12      for await ( LeftHandSideExpression of AssignmentExpression ) Statement
     13 
     14    1. Let keyResult be the result of performing ? ForIn/OfHeadEvaluation(« »,
     15       AssignmentExpression, iterate).
     16    2. Return ? ForIn/OfBodyEvaluation(LeftHandSideExpression, Statement,
     17       keyResult, assignment, labelSet).
     18 
     19    13.7.5.13 Runtime Semantics: ForIn/OfBodyEvaluation
     20 
     21    [...]
     22    5. If destructuring is true and if lhsKind is assignment, then
     23       a. Assert: lhs is a LeftHandSideExpression.
     24       b. Let assignmentPattern be the parse of the source text corresponding to
     25          lhs using AssignmentPattern as the goal symbol.
     26    [...]
     27 
     28    ArrayAssignmentPattern : [ ]
     29 
     30    1. Let iterator be GetIterator(value).
     31    2. ReturnIfAbrupt(iterator).
     32    3. Return IteratorClose(iterator, NormalCompletion(empty)).
     33 
     34    7.4.6 IteratorClose ( iterator, completion )
     35 
     36    [...]
     37    5. Let innerResult be Call(return, iterator, « »).
     38    [...]
     39 
     40 ---*/
     41 let nextCount = 0;
     42 let returnCount = 0;
     43 let thisValue = null;
     44 let args = null;
     45 let iterator = {
     46  next() {
     47    nextCount += 1;
     48    return { done: true };
     49  },
     50  return() {
     51    returnCount += 1;
     52    thisValue = this;
     53    args = arguments;
     54    return {};
     55  }
     56 };
     57 let iterable = {
     58  [Symbol.iterator]() {
     59    return iterator;
     60  }
     61 };
     62 
     63 let iterCount = 0;
     64 async function * fn() {
     65  for await ([] of [iterable]) {
     66    assert.sameValue(nextCount, 0);
     67    assert.sameValue(returnCount, 1);
     68    assert.sameValue(thisValue, iterator, 'correct `this` value');
     69    assert(!!args, 'arguments object provided');
     70    assert.sameValue(args.length, 0, 'zero arguments specified');
     71 
     72 
     73    iterCount += 1;
     74  }
     75 }
     76 
     77 let iter = fn();
     78 
     79 iter.next()
     80  .then(() => assert.sameValue(iterCount, 1, 'iteration occurred as expected'), $DONE)
     81  .then($DONE, $DONE);