JSTests/test262/test/language/expressions/async-generator/expression-yield-as-statement.js

// Copyright 2017 the V8 project authors. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.

/*---
author: Caitlin Potter <caitp@igalia.com>
esid: sec-generator-function-definitions
description: >
  `yield` is a valid statement within async generator function bodies.
flags: [async]
features: [async-iteration]
---*/

var g1 = async function*() { yield; };
var g2 = async function*() { yield 1; };

var iter1 = g1();
iter1.next().then(function(result) {
  assert.sameValue(
    result.value, undefined, "Without right-hand-side: first result `value`");
  assert.sameValue(
    result.done, false, "Without right-hand-side: first result `done` flag");
}).then(undefined, $DONE);
iter1.next().then(function(result) {
  assert.sameValue(
    result.value, undefined, "Without right-hand-side: second result `value`");
  assert.sameValue(
    result.done, true, "Without right-hand-side: second result `done` flag");
}).then(undefined, $DONE);

var iter2 = g2();
iter2.next().then(function(result) {
  assert.sameValue(
    result.value, 1, "With right-hand-side: first result `value`");
  assert.sameValue(
    result.done, false, "With right-hand-side: first result `done` flag");
}).then(undefined, $DONE);
iter2.next().then(function(result) {
  assert.sameValue(
    result.value, undefined, "With right-hand-side: second result `value`");
  assert.sameValue(
    result.done, true, "With right-hand-side: second result `done` flag");
}).then($DONE, $DONE);