JSTests/test262/test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elision.js

// This file was procedurally generated from the following sources:
// - src/dstr-binding/ary-ptrn-elision.case
// - src/dstr-binding/default/async-gen-func-expr-dflt.template
/*---
description: Elision advances iterator (async generator function expression (default parameter))
esid: sec-asyncgenerator-definitions-evaluation
features: [generators, async-iteration]
flags: [generated, async]
info: |
    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
        AsyncGeneratorBody }

        [...]
        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
           AsyncGeneratorBody, scope, strict).
        [...]


    13.3.3.6 Runtime Semantics: IteratorBindingInitialization

    ArrayBindingPattern : [ Elision ]

    1. Return the result of performing
       IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord
       as the argument.

    12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation

    Elision : ,

    1. If iteratorRecord.[[done]] is false, then
       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
       c. ReturnIfAbrupt(next).
       d. If next is false, set iteratorRecord.[[done]] to true.
    2. Return NormalCompletion(empty).

---*/
var first = 0;
var second = 0;
function* g() {
  first += 1;
  yield;
  second += 1;
};


var callCount = 0;
var f;
f = async function*([,] = g()) {
  assert.sameValue(first, 1);
  assert.sameValue(second, 0);
  callCount = callCount + 1;
};

f().next().then(() => {
    assert.sameValue(callCount, 1, 'invoked exactly once');
}).then($DONE, $DONE);