src/function-forms/default/async-arrow-function.template

// Copyright (C) 2017 Leo Balter. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.

/*---
path: language/expressions/async-arrow-function/
name: async arrow function expression
esid: sec-async-arrow-function-definitions
info: |
  14.7 Async Arrow Function Definitions

  AsyncArrowFunction :
    ...
    CoverCallExpressionAndAsyncArrowHead => AsyncConciseBody

  AsyncConciseBody :
    { AsyncFunctionBody }

  ...

  Supplemental Syntax

  When processing an instance of the production AsyncArrowFunction :
  CoverCallExpressionAndAsyncArrowHead => AsyncConciseBody the interpretation of
  CoverCallExpressionAndAsyncArrowHead is refined using the following grammar:

  AsyncArrowHead :
    async ArrowFormalParameters
flags: [async]
features: [async-functions]
---*/

var callCount = 0;

// Stores a reference `ref` for case evaluation
var ref = async (/*{ params }*/) => {
  /*{ body }*/
  callCount = callCount + 1;
};

ref(/*{ args }*/).then(() => {
  assert.sameValue(callCount, 1, 'async arrow function invoked exactly once')
}).then($DONE, $DONE);