JSTests/test262/test/language/statements/async-generator/dstr-dflt-ary-ptrn-elem-ary-elision-init.js

// This file was procedurally generated from the following sources:
// - src/dstr-binding/ary-ptrn-elem-ary-elision-init.case
// - src/dstr-binding/default/async-gen-func-decl-dflt.template
/*---
description: BindingElement with array binding pattern and initializer is used (async generator function declaration (default parameter))
esid: sec-asyncgenerator-definitions-instantiatefunctionobject
features: [generators, async-iteration]
flags: [generated, async]
info: |
    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
        ( FormalParameters ) { AsyncGeneratorBody }

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


    13.3.3.6 Runtime Semantics: IteratorBindingInitialization

    BindingElement : BindingPatternInitializer opt

    [...]
    2. If iteratorRecord.[[done]] is true, let v be undefined.
    3. If Initializer is present and v is undefined, then
       a. Let defaultValue be the result of evaluating Initializer.
       b. Let v be ? GetValue(defaultValue).
    4. Return the result of performing BindingInitialization of BindingPattern
       with v and environment as the arguments.

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


var callCount = 0;
async function* f([[,] = 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);