JSTests/test262/test/language/statements/for-await-of/async-gen-dstr-let-async-ary-ptrn-rest-id-elision.js

// This file was procedurally generated from the following sources:
// - src/dstr-binding-for-await/ary-ptrn-rest-id-elision.case
// - src/dstr-binding-for-await/default/for-await-of-async-gen-let-async.template
/*---
description: Rest element following elision elements (for-await-of statement)
esid: sec-for-in-and-for-of-statements-runtime-semantics-labelledevaluation
features: [destructuring-binding, async-iteration]
flags: [generated, async]
info: |
    IterationStatement :
        for await ( ForDeclaration of AssignmentExpression ) Statement

    [...]
    2. Return ? ForIn/OfBodyEvaluation(ForDeclaration, Statement, keyResult,
        lexicalBinding, labelSet, async).

    13.7.5.13 Runtime Semantics: ForIn/OfBodyEvaluation

    [...]
    4. Let destructuring be IsDestructuring of lhs.
    [...]
    6. Repeat
       [...]
       j. If destructuring is false, then
          [...]
       k. Else
          i. If lhsKind is assignment, then
             [...]
          ii. Else if lhsKind is varBinding, then
              [...]
          iii. Else,
               1. Assert: lhsKind is lexicalBinding.
               2. Assert: lhs is a ForDeclaration.
               3. Let status be the result of performing BindingInitialization
                  for lhs passing nextValue and iterationEnv as arguments.
          [...]

    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
    ArrayBindingPattern : [ Elisionopt BindingRestElement ]
    1. If Elision is present, then
       a. Let status be the result of performing
          IteratorDestructuringAssignmentEvaluation of Elision with
          iteratorRecord as the argument.
       b. ReturnIfAbrupt(status).
    2. Return the result of performing IteratorBindingInitialization for
       BindingRestElement with iteratorRecord and environment as arguments.
---*/
var values = [1, 2, 3, 4, 5];

var iterCount = 0;
var asyncIter = (async function*() {
  yield* [values];
})();

async function *fn() {
  for await (let [ , , ...x] of asyncIter) {
    assert(Array.isArray(x));
    assert.sameValue(x.length, 3);
    assert.sameValue(x[0], 3);
    assert.sameValue(x[1], 4);
    assert.sameValue(x[2], 5);
    assert.notSameValue(x, values);

    iterCount += 1;
  }
}

fn().next()
  .then(() => assert.sameValue(iterCount, 1, 'iteration occurred as expected'), $DONE)
  .then($DONE, $DONE);