v8/test/mjsunit/harmony/async-generators-basic.js

// Copyright 2017 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Flags: --allow-natives-syntax

function assertThrowsAsync(run, errorType, message) {
  var actual;
  var hadValue = false;
  var hadError = false;
  var promise = run();

  if (typeof promise !== "object" || typeof promise.then !== "function") {
    throw new MjsUnitAssertionError(
        `Expected ${run.toString()} to return a Promise, but it returned ` +
        PrettyPrint(promise));
  }

  promise.then(function(value) { hadValue = true; actual = value; },
               function(error) { hadError = true; actual = error; });

  assertFalse(hadValue || hadError);

  %PerformMicrotaskCheckpoint();

  if (!hadError) {
    throw new MjsUnitAssertionError(
        "Expected " + run + "() to throw " + errorType.name +
        ", but did not throw.");
  }
  if (!(actual instanceof errorType))
    throw new MjsUnitAssertionError(
        "Expected " + run + "() to throw " + errorType.name +
        ", but threw '" + actual + "'");
  if (message !== void 0 && actual.message !== message)
    throw new MjsUnitAssertionError(
        "Expected " + run + "() to throw '" + message + "', but threw '" +
        actual.message + "'");
};

function assertEqualsAsync(expected, run, msg) {
  var actual;
  var hadValue = false;
  var hadError = false;
  var promise = run();

  if (typeof promise !== "object" || typeof promise.then !== "function") {
    throw new MjsUnitAssertionError(
        `Expected ${run.toString()} to return a Promise, but it returned ` +
        `${promise}`);
  }

  promise.then(function(value) { hadValue = true; actual = value; },
               function(error) { hadError = true; actual = error; });

  assertFalse(hadValue || hadError);

  %PerformMicrotaskCheckpoint();

  if (hadError) throw actual;

  assertTrue(
      hadValue, "Expected '" + run.toString() + "' to produce a value");

  assertEquals(expected, actual, msg);
};

class MyError extends Error {};
function Thrower(msg) { throw new MyError(msg); }
function Rejecter(msg) {
  return new Promise(function(resolve, reject) {
    Promise.resolve().then(function() {
      reject(new MyError(msg));
    });
  });
}
function Resolver(msg) {
  return new Promise(function(resolve, reject) {
    Promise.resolve().then(function() {
      resolve(msg);
    });
  });
}

async function ForAwaitOfValues(it) {
  let array = [];
  for await (let x of it) array.push(x);
  return array;
}

let log = [];
function logIterResult(iter_result) {
  log.push(iter_result);
}
function logError(error) {
  log.push(error);
}

function AbortUnreachable() {
  %AbortJS("This code should not be reachable.");
}

// ----------------------------------------------------------------------------
// Do not install `AsyncGeneratorFunction` constructor on global object
assertEquals(undefined, this.AsyncGeneratorFunction);

// ----------------------------------------------------------------------------
let AsyncGenerator = Object.getPrototypeOf(async function*() {});
let AsyncGeneratorPrototype = AsyncGenerator.prototype;

// %AsyncGenerator% and %AsyncGeneratorPrototype% are both ordinary objects
assertEquals("object", typeof AsyncGenerator);
assertEquals("object", typeof AsyncGeneratorPrototype);

// %AsyncGenerator% <---> %AsyncGeneratorPrototype% circular reference
assertEquals(AsyncGenerator, AsyncGeneratorPrototype.constructor);
assertEquals(AsyncGeneratorPrototype, AsyncGenerator.prototype);

let protoDesc = Object.getOwnPropertyDescriptor(AsyncGenerator, 'prototype');
assertFalse(protoDesc.enumerable);
assertFalse(protoDesc.writable);
assertTrue(protoDesc.configurable);

let ctorDesc =
    Object.getOwnPropertyDescriptor(AsyncGeneratorPrototype, 'constructor');
assertFalse(ctorDesc.enumerable);
assertFalse(ctorDesc.writable);
assertTrue(ctorDesc.configurable);

// ----------------------------------------------------------------------------
// The AsyncGeneratorFunction Constructor is the %AsyncGeneratorFunction%
// intrinsic object and is a subclass of Function.
// (proposal-async-iteration/#sec-asyncgeneratorfunction-constructor)
let AsyncGeneratorFunction = AsyncGenerator.constructor;
assertEquals(Object.getPrototypeOf(AsyncGeneratorFunction), Function);
assertEquals(Object.getPrototypeOf(AsyncGeneratorFunction.prototype),
             Function.prototype);
assertTrue(async function*() {} instanceof Function);

// ----------------------------------------------------------------------------
// Let functionPrototype be the intrinsic object %AsyncGeneratorPrototype%.
async function* asyncGeneratorForProto() {}
assertEquals(AsyncGeneratorFunction.prototype,
             Object.getPrototypeOf(asyncGeneratorForProto));
assertEquals(AsyncGeneratorFunction.prototype,
             Object.getPrototypeOf(async function*() {}));
assertEquals(AsyncGeneratorFunction.prototype,
             Object.getPrototypeOf({ async* method() {} }.method));
assertEquals(AsyncGeneratorFunction.prototype,
             Object.getPrototypeOf(AsyncGeneratorFunction()));
assertEquals(AsyncGeneratorFunction.prototype,
             Object.getPrototypeOf(new AsyncGeneratorFunction()));

// ----------------------------------------------------------------------------
// AsyncGeneratorFunctionCreate produces a function whose prototype property is
// derived from %AsyncGeneratorPrototype%
assertEquals(AsyncGeneratorFunction.prototype.prototype,
             Object.getPrototypeOf(asyncGeneratorForProto.prototype));
assertTrue(asyncGeneratorForProto.hasOwnProperty("prototype"));
assertEquals(AsyncGeneratorFunction.prototype.prototype,
             Object.getPrototypeOf((async function*() {}).prototype));
assertTrue((async function*() {}).hasOwnProperty("prototype"));
assertEquals(AsyncGeneratorFunction.prototype.prototype,
             Object.getPrototypeOf(({ async* method() {} }).method.prototype));
assertTrue(({ async* method() {} }).method.hasOwnProperty("prototype"));
assertEquals(AsyncGeneratorFunction.prototype.prototype,
             Object.getPrototypeOf(AsyncGeneratorFunction().prototype));
assertTrue(AsyncGeneratorFunction().hasOwnProperty("prototype"));
assertEquals(AsyncGeneratorFunction.prototype.prototype,
             Object.getPrototypeOf(new AsyncGeneratorFunction().prototype));
assertTrue(new AsyncGeneratorFunction().hasOwnProperty("prototype"));

// ----------------------------------------------------------------------------
// Basic Function.prototype.toString()
async function* asyncGeneratorForToString() {}
assertEquals("async function* asyncGeneratorForToString() {}",
             asyncGeneratorForToString.toString());

assertEquals("async function*() {}", async function*() {}.toString());
assertEquals("async function* namedAsyncGeneratorForToString() {}",
             async function* namedAsyncGeneratorForToString() {}.toString());

assertEquals("async *method() { }",
             ({ async *method() { } }).method.toString());
assertEquals("async *method() { }",
             (class { static async *method() { } }).method.toString());
assertEquals("async *method() { }",
             (new (class { async *method() { } })).method.toString());

assertEquals("async function* anonymous(\n) {\n\n}",
             AsyncGeneratorFunction().toString());
assertEquals("async function* anonymous(\n) {\n\n}",
             (new AsyncGeneratorFunction()).toString());

// ----------------------------------------------------------------------------
// AsyncGenerator functions syntactically allow AwaitExpressions
assertEquals(1, async function*(a) { await 1; }.length);
assertEquals(2, async function*(a, b) { await 1; }.length);
assertEquals(1, async function*(a, b = 2) { await 1; }.length);
assertEquals(2, async function*(a, b, ...c) { await 1; }.length);

assertEquals(1, ({ async* f(a) { await 1; } }).f.length);
assertEquals(2, ({ async* f(a, b) { await 1; } }).f.length);
assertEquals(1, ({ async* f(a, b = 2) { await 1; } }).f.length);
assertEquals(2, ({ async* f(a, b, ...c) { await 1; } }).f.length);

assertEquals(1, AsyncGeneratorFunction("a", "await 1").length);
assertEquals(2, AsyncGeneratorFunction("a", "b", "await 1").length);
assertEquals(1, AsyncGeneratorFunction("a", "b = 2", "await 1").length);
assertEquals(2, AsyncGeneratorFunction("a", "b", "...c", "await 1").length);

assertEquals(1, (new AsyncGeneratorFunction("a", "await 1")).length);
assertEquals(2, (new AsyncGeneratorFunction("a", "b", "await 1")).length);
assertEquals(1, (new AsyncGeneratorFunction("a", "b = 2", "await 1")).length);
assertEquals(2,
             (new AsyncGeneratorFunction("a", "b", "...c", "await 1")).length);

// ----------------------------------------------------------------------------
// AsyncGenerator functions syntactically allow YieldExpressions
assertEquals(1, async function*(a) { yield 1; }.length);
assertEquals(2, async function*(a, b) { yield 1; }.length);
assertEquals(1, async function*(a, b = 2) { yield 1; }.length);
assertEquals(2, async function*(a, b, ...c) { yield 1; }.length);

assertEquals(1, ({ async* f(a) { yield 1; } }).f.length);
assertEquals(2, ({ async* f(a, b) { yield 1; } }).f.length);
assertEquals(1, ({ async* f(a, b = 2) { yield 1; } }).f.length);
assertEquals(2, ({ async* f(a, b, ...c) { yield 1; } }).f.length);

assertEquals(1, AsyncGeneratorFunction("a", "yield 1").length);
assertEquals(2, AsyncGeneratorFunction("a", "b", "yield 1").length);
assertEquals(1, AsyncGeneratorFunction("a", "b = 2", "yield 1").length);
assertEquals(2, AsyncGeneratorFunction("a", "b", "...c", "yield 1").length);

assertEquals(1, (new AsyncGeneratorFunction("a", "yield 1")).length);
assertEquals(2, (new AsyncGeneratorFunction("a", "b", "yield 1")).length);
assertEquals(1, (new AsyncGeneratorFunction("a", "b = 2", "yield 1")).length);
assertEquals(2,
             (new AsyncGeneratorFunction("a", "b", "...c", "yield 1")).length);

// ----------------------------------------------------------------------------
// AsyncGeneratorFunction.prototype[ @@toStringTag ]
var descriptor =
    Object.getOwnPropertyDescriptor(AsyncGeneratorFunction.prototype,
                                    Symbol.toStringTag);
assertEquals("AsyncGeneratorFunction", descriptor.value);
assertEquals(false, descriptor.enumerable);
assertEquals(false, descriptor.writable);
assertEquals(true, descriptor.configurable);

assertEquals(1, AsyncGeneratorFunction.length);

// ----------------------------------------------------------------------------
// Let F be ! FunctionAllocate(functionPrototype, Strict, "non-constructor")
async function* asyncNonConstructorDecl() {}
assertThrows(() => new asyncNonConstructorDecl(), TypeError);
assertThrows(() => asyncNonConstructorDecl.caller, TypeError);
assertThrows(() => asyncNonConstructorDecl.arguments, TypeError);

assertThrows(() => new (async function*() {}), TypeError);
assertThrows(() => (async function*() {}).caller, TypeError);
assertThrows(() => (async function*() {}).arguments, TypeError);

assertThrows(
    () => new ({ async* nonConstructor() {} }).nonConstructor(), TypeError);
assertThrows(
    () => ({ async* nonConstructor() {} }).nonConstructor.caller, TypeError);
assertThrows(
    () => ({ async* nonConstructor() {} }).nonConstructor.arguments, TypeError);

assertThrows(
    () => new (AsyncGeneratorFunction("nonconstructor"))(), TypeError);
assertThrows(
    () => AsyncGeneratorFunction("nonconstructor").caller, TypeError);
assertThrows(
    () => AsyncGeneratorFunction("nonconstructor").arguments, TypeError);

assertThrows(
    () => new (new AsyncGeneratorFunction("nonconstructor"))(), TypeError);
assertThrows(
    () => (new AsyncGeneratorFunction("nonconstructor")).caller, TypeError);
assertThrows(
    () => (new AsyncGeneratorFunction("nonconstructor")).arguments, TypeError);

// ----------------------------------------------------------------------------
// Empty functions
async function* emptyAsyncGenerator() {}
let it = emptyAsyncGenerator();
assertEqualsAsync({ value: undefined, done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (async function* emptyAsyncGeneratorExpr() { })();
assertEqualsAsync({ value: undefined, done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = ({ async* method() { } }).method();
assertEqualsAsync({ value: undefined, done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = AsyncGeneratorFunction(``)();
assertEqualsAsync({ value: undefined, done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (new AsyncGeneratorFunction(``))();
assertEqualsAsync({ value: undefined, done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());


// ----------------------------------------------------------------------------
// Top-level ReturnStatement
async function* asyncGeneratorForReturn() {
  return "boop1";
  throw "(unreachble)";
}
it = asyncGeneratorForReturn();
assertEqualsAsync({ value: "boop1", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (async function*() {
  return "boop2";
  throw "(unreachable)";
})();
assertEqualsAsync({ value: "boop2", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = ({ async* method() { return "boop3"; throw "(unreachable)"; } }).method();
assertEqualsAsync({ value: "boop3", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = AsyncGeneratorFunction(`
  return "boop4";
  throw "(unreachable)";`)();
assertEqualsAsync({ value: "boop4", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (new AsyncGeneratorFunction(`
  return "boop5";
  throw "(unreachable)";`))();
assertEqualsAsync({ value: "boop5", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

// ----------------------------------------------------------------------------
// Top-level ReturnStatement after await
async function* asyncGeneratorForReturnAfterAwait() {
  await 1;
  return "boop6";
  throw "(unreachable)";
}
it = asyncGeneratorForReturnAfterAwait();
assertEqualsAsync({ value: "boop6", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (async function*() { await 1; return "boop7"; throw "(unreachable)"; })();
assertEqualsAsync({ value: "boop7", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = ({
  async* method() {
    await 1;
    return "boop8";
    throw "(unreachable)";
  }
}).method();
assertEqualsAsync({ value: "boop8", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = AsyncGeneratorFunction(`
  await 1;
  return "boop9";
  throw "(unreachable)"`)();
assertEqualsAsync({ value: "boop9", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (new AsyncGeneratorFunction(`
  await 1;
  return "boop10";
  throw "(unreachable)"`))();
assertEqualsAsync({ value: "boop10", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

// ----------------------------------------------------------------------------
// Top-level Yields

async function* asyncGeneratorForYields() {
  yield 1;
  yield await Resolver(2);
  yield Resolver(3);
  return 4;
  throw "(unreachable)";
}

it = asyncGeneratorForYields();
assertEqualsAsync([1, 2, 3], () => ForAwaitOfValues(it));
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (async function*() {
  yield "cow";
  yield await Resolver("bird");
  yield await "dog";
  yield Resolver("donkey");
  return "badger";
  throw "(unreachable)"; })();
assertEqualsAsync(["cow", "bird", "dog", "donkey"], () => ForAwaitOfValues(it));
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = ({
  async* method() {
    yield "A";
    yield await Resolver("B");
    yield await "C";
    yield Resolver("CC");
    return "D";
    throw "(unreachable)";
  }
}).method();
assertEqualsAsync(["A", "B", "C", "CC"], () => ForAwaitOfValues(it));
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = AsyncGeneratorFunction(`
  yield "alpha";
  yield await Resolver("beta");
  yield await "gamma";
  yield Resolver("delta");
  return "epsilon";
  throw "(unreachable)"`)();
assertEqualsAsync(["alpha", "beta", "gamma", "delta"],
                  () => ForAwaitOfValues(it));
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (new AsyncGeneratorFunction(`
  yield "α";
  yield await Resolver("β");
  yield await "γ";
  yield Resolver("δ");
  return "ε";
  throw "(unreachable)"`))();
assertEqualsAsync(["α", "β", "γ", "δ"], () => ForAwaitOfValues(it));
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

// ----------------------------------------------------------------------------
// Nested Resume via [AsyncGenerator].next()
log = [];
async function* asyncGeneratorForNestedResumeNext() {
  it.next().then(logIterResult, logError);
  it.next().then(logIterResult, logError);
  yield "rootbeer";
  yield await Resolver("float");
}
it = asyncGeneratorForNestedResumeNext();
it.next().then(logIterResult, AbortUnreachable);
%PerformMicrotaskCheckpoint();
assertEquals([
  { value: "rootbeer", done: false },
  { value: "float", done: false },
  { value: undefined, done: true }
], log);

log = [];
let asyncGeneratorExprForNestedResumeNext = async function*() {
  it.next().then(logIterResult, logError);
  it.next().then(logIterResult, logError);
  yield "first";
  yield await Resolver("second");
};
it = asyncGeneratorExprForNestedResumeNext();
it.next().then(logIterResult, AbortUnreachable);
%PerformMicrotaskCheckpoint();
assertEquals([
  { value: "first", done: false },
  { value: "second", done: false },
  { value: undefined, done: true }
], log);

log = [];
let asyncGeneratorMethodForNestedResumeNext = ({
  async* method() {
    it.next().then(logIterResult, logError);
    it.next().then(logIterResult, logError);
    yield "remember";
    yield await Resolver("the cant!");
  }
}).method;
it = asyncGeneratorMethodForNestedResumeNext();
it.next().then(logIterResult, AbortUnreachable);
%PerformMicrotaskCheckpoint();
assertEquals([
  { value: "remember", done: false },
  { value: "the cant!", done: false },
  { value: undefined, done: true }
], log);

log = [];
let asyncGeneratorCallEvalForNestedResumeNext =
    AsyncGeneratorFunction(`
      it.next().then(logIterResult, logError);
      it.next().then(logIterResult, logError);
      yield "reading";
      yield await Resolver("rainbow!");`);
it = asyncGeneratorCallEvalForNestedResumeNext();
it.next().then(logIterResult, AbortUnreachable);
%PerformMicrotaskCheckpoint();
assertEquals([
  { value: "reading", done: false },
  { value: "rainbow!", done: false },
  { value: undefined, done: true }
], log);

log = [];
let asyncGeneratorNewEvalForNestedResumeNext =
    new AsyncGeneratorFunction(`
      it.next().then(logIterResult, logError);
      it.next().then(logIterResult, logError);
      yield 731;
      yield await Resolver("BB!");`);
it = asyncGeneratorNewEvalForNestedResumeNext();
it.next().then(logIterResult, AbortUnreachable);
%PerformMicrotaskCheckpoint();
assertEquals([
  { value: 731, done: false },
  { value: "BB!", done: false },
  { value: undefined, done: true }
], log);

// ----------------------------------------------------------------------------
// Nested Resume via [AsyncGenerator].throw()
log = [];
async function* asyncGeneratorForNestedResumeThrow() {
  try {
    it.throw(await Rejecter("...")).then(logIterResult, logError);
  } catch (e) {
    it.throw("throw2").then(logIterResult, logError);
    it.next().then(logIterResult, logError);
    throw "throw1";
  }
  AbortUnreachable();
}
it = asyncGeneratorForNestedResumeThrow();
it.next().then(logIterResult, logError);
%PerformMicrotaskCheckpoint();
assertEquals([
  "throw1",
  "throw2",
  { value: undefined, done: true }
], log);

log = [];
let asyncGeneratorExprForNestedResumeThrow = async function*() {
  try {
    it.throw(await Rejecter("...")).then(logIterResult, logError);
  } catch (e) {
    it.throw("throw4").then(logIterResult, logError);
    it.next().then(logIterResult, logError);
    throw "throw3";
  }
  AbortUnreachable();
};
it = asyncGeneratorExprForNestedResumeThrow();
it.next().then(logIterResult, logError);
%PerformMicrotaskCheckpoint();
assertEquals([
  "throw3",
  "throw4",
  { value: undefined, done: true }
], log);

log = [];
let asyncGeneratorMethodForNestedResumeThrow = ({
  async* method() {
    try {
      it.throw(await Rejecter("...")).then(logIterResult, logError);
    } catch (e) {
      it.throw("throw6").then(logIterResult, logError);
      it.next().then(logIterResult, logError);
      throw "throw5";
    }
    AbortUnreachable();
  }
}).method;
it = asyncGeneratorMethodForNestedResumeThrow();
it.next().then(logIterResult, logError);
%PerformMicrotaskCheckpoint();
assertEquals([
  "throw5",
  "throw6",
  { value: undefined, done: true }
], log);

log = [];
let asyncGeneratorCallEvalForNestedResumeThrow =
    AsyncGeneratorFunction(`
      try {
        it.throw(await Rejecter("...")).then(logIterResult, logError);
      } catch (e) {
        it.throw("throw8").then(logIterResult, logError);
        it.next().then(logIterResult, logError);
        throw "throw7";
      }
      AbortUnreachable();`);
it = asyncGeneratorCallEvalForNestedResumeThrow();
it.next().then(logIterResult, logError);
%PerformMicrotaskCheckpoint();
assertEquals([
  "throw7",
  "throw8",
  { value: undefined, done: true }
], log);

log = [];
let asyncGeneratorNewEvalForNestedResumeThrow =
    new AsyncGeneratorFunction(`
      try {
        it.throw(await Rejecter("...")).then(logIterResult, logError);
      } catch (e) {
        it.throw("throw10").then(logIterResult, logError);
        it.next().then(logIterResult, logError);
        throw "throw9";
      }
      AbortUnreachable();`);
it = asyncGeneratorNewEvalForNestedResumeThrow();
it.next().then(logIterResult, logError);
%PerformMicrotaskCheckpoint();
assertEquals([
  "throw9",
  "throw10",
  { value: undefined, done: true }
], log);

// ----------------------------------------------------------------------------
// Nested Resume via [AsyncGenerator].return()
log = [];
async function* asyncGeneratorForNestedResumeReturn() {
  it.return("step2").then(logIterResult, logError);
  it.next().then(logIterResult, logError);
  yield "step1";
  AbortUnreachable();
}
it = asyncGeneratorForNestedResumeReturn();
it.next().then(logIterResult, logError);
%PerformMicrotaskCheckpoint();
assertEquals([
  { value: "step1", done: false },
  { value: "step2", done: true },
  { value: undefined, done: true },
], log);

log = [];
let asyncGeneratorExprForNestedResumeReturn = async function*() {
  it.return("step4").then(logIterResult, logError);
  it.next().then(logIterResult, logError);
  yield "step3";
};
it = asyncGeneratorExprForNestedResumeReturn();
it.next().then(logIterResult, logError);
%PerformMicrotaskCheckpoint();
assertEquals([
  { value: "step3", done: false },
  { value: "step4", done: true },
  { value: undefined, done: true },
], log);

log = [];
let asyncGeneratorMethodForNestedResumeReturn = ({
  async* method() {
    it.return("step6").then(logIterResult, logError);
    it.next().then(logIterResult, logError);
    yield "step5";
  }
}).method;
it = asyncGeneratorMethodForNestedResumeReturn();
it.next().then(logIterResult, logError);
%PerformMicrotaskCheckpoint();
assertEquals([
  { value: "step5", done: false },
  { value: "step6", done: true },
  { value: undefined, done: true },
], log);

log = [];
let asyncGeneratorCallEvalForNestedResumeReturn =
    AsyncGeneratorFunction(`
      it.return("step8").then(logIterResult, logError);
      it.next().then(logIterResult, logError);
      yield "step7";`);
it = asyncGeneratorCallEvalForNestedResumeReturn();
it.next().then(logIterResult, logError);
%PerformMicrotaskCheckpoint();
assertEquals([
  { value: "step7", done: false },
  { value: "step8", done: true },
  { value: undefined, done: true },
], log);

log = [];
let asyncGeneratorNewEvalForNestedResumeReturn =
    new AsyncGeneratorFunction(`
      it.return("step10").then(logIterResult, logError);
      it.next().then(logIterResult, logError);
      yield "step9";`);
it = asyncGeneratorNewEvalForNestedResumeReturn();
it.next().then(logIterResult, logError);
%PerformMicrotaskCheckpoint();
assertEquals([
  { value: "step9", done: false },
  { value: "step10", done: true },
  { value: undefined, done: true },
], log);

// ----------------------------------------------------------------------------
// Top-level Yield ThrowStatement

async function* asyncGeneratorForYieldThrow() {
  yield await Thrower("OOPS1");
  throw "(unreachable)";
}
it = asyncGeneratorForYieldThrow();
assertThrowsAsync(() => it.next(), MyError, "OOPS1");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (async function*() { yield Thrower("OOPS2"); throw "(unreachable)"; })();
assertThrowsAsync(() => it.next(), MyError, "OOPS2");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = ({
  async* method() {
    yield Thrower("OOPS3");
    throw "(unreachable)";
  }
}).method();
assertThrowsAsync(() => it.next(), MyError, "OOPS3");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = AsyncGeneratorFunction(`
  yield Thrower("OOPS4");
  throw "(unreachable)"`)();
assertThrowsAsync(() => it.next(), MyError, "OOPS4");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (new AsyncGeneratorFunction(`
  yield Thrower("OOPS5");
  throw "(unreachable)"`))();
assertThrowsAsync(() => it.next(), MyError, "OOPS5");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

// ----------------------------------------------------------------------------
// Top-level Yield Awaited Rejection
async function* asyncGeneratorForYieldAwaitedRejection() {
  yield await Rejecter("OOPS1");
  throw "(unreachable)";
}
it = asyncGeneratorForYieldAwaitedRejection();
assertThrowsAsync(() => it.next(), MyError, "OOPS1");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (async function*() {
  yield await Rejecter("OOPS2");
  throw "(unreachable)";
})();
assertThrowsAsync(() => it.next(), MyError, "OOPS2");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = ({
  async* method() {
    yield await Rejecter("OOPS3");
    throw "(unreachable)";
  }
}).method();
assertThrowsAsync(() => it.next(), MyError, "OOPS3");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = AsyncGeneratorFunction(`
  yield await Rejecter("OOPS4");
  throw "(unreachable)"`)();
assertThrowsAsync(() => it.next(), MyError, "OOPS4");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (new AsyncGeneratorFunction(`
  yield await Rejecter("OOPS5");
  throw "(unreachable)"`))();
assertThrowsAsync(() => it.next(), MyError, "OOPS5");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());


// ----------------------------------------------------------------------------
// Top-level ThrowStatement
async function* asyncGeneratorForThrow() {
  throw new MyError("BOOM1");
  throw "(unreachable)";
}
it = asyncGeneratorForThrow();
assertThrowsAsync(() => it.next(), MyError, "BOOM1");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (async function*() {
  throw new MyError("BOOM2");
  throw "(unreachable)";
})();
assertThrowsAsync(() => it.next(), MyError, "BOOM2");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = ({
  async* method() {
    throw new MyError("BOOM3");
    throw "(unreachable)";
  }
}).method();
assertThrowsAsync(() => it.next(), MyError, "BOOM3");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  throw new MyError("BOOM4");
  throw "(unreachable)";`))()
assertThrowsAsync(() => it.next(), MyError, "BOOM4");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  throw new MyError("BOOM5");
  throw "(unreachable)";`))()
assertThrowsAsync(() => it.next(), MyError, "BOOM5");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

// ----------------------------------------------------------------------------
// Top-level ThrowStatement after Await
async function* asyncGeneratorForThrowAfterAwait() {
  await 1;
  throw new MyError("BOOM6");
  throw "(unreachable)";
}
it = asyncGeneratorForThrowAfterAwait();
assertThrowsAsync(() => it.next(), MyError, "BOOM6");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (async function*() {
  await 1;
  throw new MyError("BOOM7");
  throw "(unreachable)";
})();
assertThrowsAsync(() => it.next(), MyError, "BOOM7");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = ({
  async* method() {
    await 1;
    throw new MyError("BOOM8");
    throw "(unreachable)";
  }
}).method();
assertThrowsAsync(() => it.next(), MyError, "BOOM8");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  await 1;
  throw new MyError("BOOM9");
  throw "(unreachable)";`))();
assertThrowsAsync(() => it.next(), MyError, "BOOM9");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (new AsyncGeneratorFunction(`
  await 1;
  throw new MyError("BOOM10");
  throw "(unreachable)";`))();
assertThrowsAsync(() => it.next(), MyError, "BOOM10");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

// ----------------------------------------------------------------------------
// Top-level Awaited rejection
async function* asyncGeneratorForAwaitedRejection() {
  await Rejecter("BOOM11");
  throw "(unreachable)";
}
it = asyncGeneratorForAwaitedRejection();
assertThrowsAsync(() => it.next(), MyError, "BOOM11");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (async function*() {
  await Rejecter("BOOM12");
  throw "(unreachable)";
})();
assertThrowsAsync(() => it.next(), MyError, "BOOM12");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = ({
  async* method() {
    await Rejecter("BOOM13");
    throw "(unreachable)";
  }
}).method();

assertThrowsAsync(() => it.next(), MyError, "BOOM13");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  await Rejecter("BOOM14");
  throw "(unreachable)";`))();
assertThrowsAsync(() => it.next(), MyError, "BOOM14");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (new AsyncGeneratorFunction(`
  await Rejecter("BOOM15");
  throw "(unreachable)";`))();
assertThrowsAsync(() => it.next(), MyError, "BOOM15");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

// ----------------------------------------------------------------------------
// Caught ThrowStatement
async function* asyncGeneratorForCaughtThrow() {
  try {
    throw new MyError("BOOM1");
  } catch (e) {
    return "caught1";
  }
  throw "(unreachable)";
}
it = asyncGeneratorForCaughtThrow();
assertEqualsAsync({ value: "caught1", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (async function*() {
  try {
    throw new MyError("BOOM2");
  } catch (e) {
    return "caught2";
  }
  throw "(unreachable)";
})();
assertEqualsAsync({ value: "caught2", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = ({
  async* method() {
    try {
      throw new MyError("BOOM3");
    } catch (e) {
      return "caught3";
    }
    throw "(unreachable)";
  }
}).method();
assertEqualsAsync({ value: "caught3", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  try {
    throw new MyError("BOOM4");
  } catch (e) {
    return "caught4";
  }
  throw "(unreachable)";`))()
assertEqualsAsync({ value: "caught4", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  try {
    throw new MyError("BOOM5");
  } catch (e) {
    return "caught5";
  }
  throw "(unreachable)";`))()
assertEqualsAsync({ value: "caught5", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

// ----------------------------------------------------------------------------
// Caught ThrowStatement and rethrow
async function* asyncGeneratorForCaughtRethrow() {
  try {
    throw new MyError("BOOM1");
  } catch (e) {
    throw new MyError("RETHROW1");
  }
  throw "(unreachable)";
}
it = asyncGeneratorForCaughtRethrow();
assertThrowsAsync(() => it.next(), MyError, "RETHROW1");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (async function*() {
  try {
    throw new MyError("BOOM2");
  } catch (e) {
    throw new MyError("RETHROW2");
  }
  throw "(unreachable)";
})();
assertThrowsAsync(() => it.next(), MyError, "RETHROW2");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = ({
  async* method() {
    try {
      throw new MyError("BOOM3");
    } catch (e) {
      throw new MyError("RETHROW3");
    }
    throw "(unreachable)";
  }
}).method();
assertThrowsAsync(() => it.next(), MyError, "RETHROW3");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  try {
    throw new MyError("BOOM4");
  } catch (e) {
    throw new MyError("RETHROW4");
  }
  throw "(unreachable)";`))()
assertThrowsAsync(() => it.next(), MyError, "RETHROW4");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  try {
    throw new MyError("BOOM5");
  } catch (e) {
    throw new MyError("RETHROW5");
  }
  throw "(unreachable)";`))()
assertThrowsAsync(() => it.next(), MyError, "RETHROW5");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

// ----------------------------------------------------------------------------
// ReturnStatement in Try, ReturnStatement in Finally
async function* asyncGeneratorForReturnInTryReturnInFinally() {
  try {
    return "early1"
  } finally {
    return "later1";
  }
  throw "(unreachable)";
}
it = asyncGeneratorForReturnInTryReturnInFinally();
assertEqualsAsync({ value: "later1", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (async function*() {
  try {
    return "early2";
  } finally {
    return "later2";
  }
  throw "(unreachable)";
})();
assertEqualsAsync({ value: "later2", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = ({
  async* method() {
    try {
      return "early3";
    } finally {
      return "later3";
    }
    throw "(unreachable)";
  }
}).method();
assertEqualsAsync({ value: "later3", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  try {
    return "early4";
  } finally {
    return "later4";
  }
  throw "(unreachable)";`))()
assertEqualsAsync({ value: "later4", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  try {
    return "early5";
  } finally {
    return "later5";
  }
  throw "(unreachable)";`))()
assertEqualsAsync({ value: "later5", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

// ----------------------------------------------------------------------------
// ThrowStatement in Try, ReturnStatement in Finally
async function* asyncGeneratorForThrowInTryReturnInFinally() {
  try {
    throw new MyError("BOOM1");
  } finally {
    return "later1";
  }
  throw "(unreachable)";
}
it = asyncGeneratorForThrowInTryReturnInFinally();
assertEqualsAsync({ value: "later1", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (async function*() {
  try {
    throw new MyError("BOOM2");
  } finally {
    return "later2";
  }
  throw "(unreachable)";
})();
assertEqualsAsync({ value: "later2", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = ({
  async* method() {
    try {
      throw new MyError("BOOM3");
    } finally {
      return "later3";
    }
    throw "(unreachable)";
  }
}).method();
assertEqualsAsync({ value: "later3", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  try {
    throw new MyError("BOOM4");
  } finally {
    return "later4";
  }
  throw "(unreachable)";`))()
assertEqualsAsync({ value: "later4", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  try {
    throw new MyError("BOOM5");
  } finally {
    return "later5";
  }
  throw "(unreachable)";`))()
assertEqualsAsync({ value: "later5", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

// ----------------------------------------------------------------------------
// Awaited Rejection in Try, ReturnStatement in Finally
async function* asyncGeneratorForAwaitRejectionInTryReturnInFinally() {
  try {
    await Rejecter("BOOM1");
  } finally {
    return "later1";
  }
  throw "(unreachable)";
}
it = asyncGeneratorForThrowInTryReturnInFinally();
assertEqualsAsync({ value: "later1", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (async function*() {
  try {
    await Rejecter("BOOM2");
  } finally {
    return "later2";
  }
  throw "(unreachable)";
})();
assertEqualsAsync({ value: "later2", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = ({
  async* method() {
    try {
      await Rejecter("BOOM3");
    } finally {
      return "later3";
    }
    throw "(unreachable)";
  }
}).method();
assertEqualsAsync({ value: "later3", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  try {
    await Rejecter("BOOM4");
  } finally {
    return "later4";
  }
  throw "(unreachable)";`))()
assertEqualsAsync({ value: "later4", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  try {
    await Rejecter("BOOM5");
  } finally {
    return "later5";
  }
  throw "(unreachable)";`))()
assertEqualsAsync({ value: "later5", done: true }, () => it.next());
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

// ----------------------------------------------------------------------------
// ReturnStatement in Try, ThrowStatement in Finally
async function* asyncGeneratorForReturnInTryThrowInFinally() {
  try {
    return "early1"
  } finally {
    throw new MyError("BOOM1");
  }
  throw "(unreachable)";
}
it = asyncGeneratorForReturnInTryThrowInFinally();
assertThrowsAsync(() => it.next(), MyError, "BOOM1");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (async function*() {
  try {
    return "early2";
  } finally {
    throw new MyError("BOOM2");
  }
  throw "(unreachable)";
})();
assertThrowsAsync(() => it.next(), MyError, "BOOM2");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = ({
  async* method() {
    try {
      return "early3";
    } finally {
      throw new MyError("BOOM3");
    }
    throw "(unreachable)";
  }
}).method();
assertThrowsAsync(() => it.next(), MyError, "BOOM3");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  try {
    return "early4";
  } finally {
    throw new MyError("BOOM4");
  }
  throw "(unreachable)";`))()
assertThrowsAsync(() => it.next(), MyError, "BOOM4");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  try {
    return "early5";
  } finally {
    throw new MyError("BOOM5");
  }
  throw "(unreachable)";`))()
assertThrowsAsync(() => it.next(), MyError, "BOOM5");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

// ----------------------------------------------------------------------------
// ThrowStatement in Try, ThrowStatement in Finally

async function* asyncGeneratorForThrowInTryThrowInFinally() {
  try {
    throw new MyError("EARLY1");
  } finally {
    throw new MyError("BOOM1");
  }
  throw "(unreachable)";
}
it = asyncGeneratorForThrowInTryThrowInFinally();
assertThrowsAsync(() => it.next(), MyError, "BOOM1");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (async function*() {
  try {
    throw new MyError("EARLY2");
  } finally {
    throw new MyError("BOOM2");
  }
  throw "(unreachable)";
})();
assertThrowsAsync(() => it.next(), MyError, "BOOM2");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = ({
  async* method() {
    try {
      throw new MyError("EARLY3");
    } finally {
      throw new MyError("BOOM3");
    }
    throw "(unreachable)";
  }
}).method();
assertThrowsAsync(() => it.next(), MyError, "BOOM3");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  try {
    throw new MyError("EARLY4");
  } finally {
    throw new MyError("BOOM4");
  }
  throw "(unreachable)";`))()
assertThrowsAsync(() => it.next(), MyError, "BOOM4");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  try {
    throw new MyError("EARLY5");
  } finally {
    throw new MyError("BOOM5");
  }
  throw "(unreachable)";`))()
assertThrowsAsync(() => it.next(), MyError, "BOOM5");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

// ----------------------------------------------------------------------------
// Awaited Rejection in Try, ThrowStatement in Finally

async function* asyncGeneratorForAwaitedRejectInTryThrowInFinally() {
  try {
    await Rejecter("EARLY1");
  } finally {
    throw new MyError("BOOM1");
  }
  throw "(unreachable)";
}
it = asyncGeneratorForAwaitedRejectInTryThrowInFinally();
assertThrowsAsync(() => it.next(), MyError, "BOOM1");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (async function*() {
  try {
    await Rejecter("EARLY2");
  } finally {
    throw new MyError("BOOM2");
  }
  throw "(unreachable)";
})();
assertThrowsAsync(() => it.next(), MyError, "BOOM2");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = ({
  async* method() {
    try {
      await Rejecter("EARLY3");
    } finally {
      throw new MyError("BOOM3");
    }
    throw "(unreachable)";
  }
}).method();
assertThrowsAsync(() => it.next(), MyError, "BOOM3");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  try {
    await Rejecter("EARLY4");
  } finally {
    throw new MyError("BOOM4");
  }
  throw "(unreachable)";`))()
assertThrowsAsync(() => it.next(), MyError, "BOOM4");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  try {
    await Rejecter("EARLY5");
  } finally {
    throw new MyError("BOOM5");
  }
  throw "(unreachable)";`))()
assertThrowsAsync(() => it.next(), MyError, "BOOM5");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

// ----------------------------------------------------------------------------
// ReturnStatement in Try, Awaited Rejection in Finally
async function* asyncGeneratorForReturnInTryAwaitedRejectionInFinally() {
  try {
    return "early1"
  } finally {
    await Rejecter("BOOM1");
  }
  throw "(unreachable)";
}
it = asyncGeneratorForReturnInTryAwaitedRejectionInFinally();
assertThrowsAsync(() => it.next(), MyError, "BOOM1");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (async function*() {
  try {
    return "early2";
  } finally {
    await Rejecter("BOOM2");
  }
  throw "(unreachable)";
})();
assertThrowsAsync(() => it.next(), MyError, "BOOM2");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = ({
  async* method() {
    try {
      return "early3";
    } finally {
      await Rejecter("BOOM3");
    }
    throw "(unreachable)";
  }
}).method();
assertThrowsAsync(() => it.next(), MyError, "BOOM3");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  try {
    return "early4";
  } finally {
    await Rejecter("BOOM4");
  }
  throw "(unreachable)";`))()
assertThrowsAsync(() => it.next(), MyError, "BOOM4");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  try {
    return "early5";
  } finally {
    await Rejecter("BOOM5");
  }
  throw "(unreachable)";`))()
assertThrowsAsync(() => it.next(), MyError, "BOOM5");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

// ----------------------------------------------------------------------------
// ThrowStatement in Try, Awaited Rejection in Finally

async function* asyncGeneratorForThrowInTryAwaitedRejectionInFinally() {
  try {
    throw new MyError("EARLY1");
  } finally {
    await Rejecter("BOOM1");
  }
  throw "(unreachable)";
}
it = asyncGeneratorForThrowInTryAwaitedRejectionInFinally();
assertThrowsAsync(() => it.next(), MyError, "BOOM1");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (async function*() {
  try {
    throw new MyError("EARLY2");
  } finally {
    await Rejecter("BOOM2");
  }
  throw "(unreachable)";
})();
assertThrowsAsync(() => it.next(), MyError, "BOOM2");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = ({
  async* method() {
    try {
      throw new MyError("EARLY3");
    } finally {
      await Rejecter("BOOM3");
    }
    throw "(unreachable)";
  }
}).method();
assertThrowsAsync(() => it.next(), MyError, "BOOM3");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  try {
    throw new MyError("EARLY4");
  } finally {
    await Rejecter("BOOM4");
  }
  throw "(unreachable)";`))()
assertThrowsAsync(() => it.next(), MyError, "BOOM4");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  try {
    throw new MyError("EARLY5");
  } finally {
    await Rejecter("BOOM5");
  }
  throw "(unreachable)";`))()
assertThrowsAsync(() => it.next(), MyError, "BOOM5");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

// ----------------------------------------------------------------------------
// Awaited Rejection in Try, Awaited Rejection in Finally

async function* asyncGeneratorForAwaitedRejectInTryAwaitedRejectionInFinally() {
  try {
    await Rejecter("EARLY1");
  } finally {
    await Rejecter("BOOM1");
  }
  throw "(unreachable)";
}
it = asyncGeneratorForAwaitedRejectInTryAwaitedRejectionInFinally();
assertThrowsAsync(() => it.next(), MyError, "BOOM1");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (async function*() {
  try {
    await Rejecter("EARLY2");
  } finally {
    await Rejecter("BOOM2");
  }
  throw "(unreachable)";
})();
assertThrowsAsync(() => it.next(), MyError, "BOOM2");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = ({
  async* method() {
    try {
      await Rejecter("EARLY3");
    } finally {
      await Rejecter("BOOM3");
    }
    throw "(unreachable)";
  }
}).method();
assertThrowsAsync(() => it.next(), MyError, "BOOM3");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  try {
    await Rejecter("EARLY4");
  } finally {
    await Rejecter("BOOM4");
  }
  throw "(unreachable)";`))()
assertThrowsAsync(() => it.next(), MyError, "BOOM4");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

it = (AsyncGeneratorFunction(`
  try {
    await Rejecter("EARLY5");
  } finally {
    await Rejecter("BOOM5");
  }
  throw "(unreachable)";`))()
assertThrowsAsync(() => it.next(), MyError, "BOOM5");
assertEqualsAsync({ value: undefined, done: true }, () => it.next());

// ----------------------------------------------------------------------------
// Early errors during parameter initialization

async function* asyncGeneratorForParameterInitializationErrors(
    [...a], b = c, d) {
  AbortUnreachable();
}
assertThrows(() => asyncGeneratorForParameterInitializationErrors(null),
             TypeError);
assertThrows(() => asyncGeneratorForParameterInitializationErrors([]),
             ReferenceError);

let asyncGeneratorExprForParameterInitializationErrors =
    async function*([...a], b = c, d) {
      AbortUnreachable();
    };
assertThrows(() => asyncGeneratorExprForParameterInitializationErrors(null),
             TypeError);
assertThrows(() => asyncGeneratorExprForParameterInitializationErrors([]),
             ReferenceError);

let asyncGeneratorMethodForParameterInitializationErrors = ({
  async* method([...a], b = c, d) {
    AbortUnreachable();
  }
}).method;
assertThrows(() => asyncGeneratorMethodForParameterInitializationErrors(null),
             TypeError);
assertThrows(() => asyncGeneratorMethodForParameterInitializationErrors([]),
             ReferenceError);

let asyncGeneratorCallEvalForParameterInitializationErrors =
    AsyncGeneratorFunction("[...a], b = c, d", `AbortUnreachable();`);
assertThrows(() => asyncGeneratorCallEvalForParameterInitializationErrors(null),
             TypeError);
assertThrows(() => asyncGeneratorCallEvalForParameterInitializationErrors([]),
             ReferenceError);

let asyncGeneratorNewEvalForParameterInitializationErrors =
    new AsyncGeneratorFunction("[...a], b = c, d",
                               `AbortUnreachable();`);
assertThrows(() => asyncGeneratorNewEvalForParameterInitializationErrors(null),
             TypeError);
assertThrows(() => asyncGeneratorNewEvalForParameterInitializationErrors([]),
             ReferenceError);

// ----------------------------------------------------------------------------
// Invoke [AsyncGenerator].return() when generator is in state suspendedStart

async function* asyncGeneratorForReturnSuspendedStart() {
  AbortUnreachable();
}
it = asyncGeneratorForReturnSuspendedStart();
assertEqualsAsync({ value: "ret1", done: true }, () => it.return("ret1"));
assertEqualsAsync({ value: undefined, done: true }, () => it.next("x"));
assertEqualsAsync({ value: "nores", done: true },
                  () => it.return("nores"));
assertThrowsAsync(() => it.throw(new MyError("nores")), MyError, "nores");

it = (async function*() {
  AbortUnreachable();
})();
assertEqualsAsync({ value: "ret2", done: true }, () => it.return("ret2"));
assertEqualsAsync({ value: undefined, done: true }, () => it.next("x"));
assertEqualsAsync({ value: "nores", done: true },
                  () => it.return("nores"));
assertThrowsAsync(() => it.throw(new MyError("nores")), MyError, "nores");

it = ({
  async* method() {
    AbortUnreachable();
  }
}).method();
assertEqualsAsync({ value: "ret3", done: true }, () => it.return("ret3"));
assertEqualsAsync({ value: undefined, done: true }, () => it.next("x"));
assertEqualsAsync({ value: "nores", done: true },
                  () => it.return("nores"));
assertThrowsAsync(() => it.throw(new MyError("nores")), MyError, "nores");

it = (AsyncGeneratorFunction(`AbortUnreachable();`))();
assertEqualsAsync({ value: "ret4", done: true }, () => it.return("ret4"));
assertEqualsAsync({ value: undefined, done: true }, () => it.next("x"));
assertEqualsAsync({ value: "nores", done: true },
                  () => it.return("nores"));
assertThrowsAsync(() => it.throw(new MyError("nores")), MyError, "nores");

it = (AsyncGeneratorFunction(`AbortUnreachable();`))();
assertEqualsAsync({ value: "ret5", done: true }, () => it.return("ret5"));
assertEqualsAsync({ value: undefined, done: true }, () => it.next("x"));
assertEqualsAsync({ value: "nores", done: true },
                  () => it.return("nores"));
assertThrowsAsync(() => it.throw(new MyError("nores")), MyError, "nores");

// ----------------------------------------------------------------------------
// Invoke [AsyncGenerator].throw() when generator is in state suspendedStart

async function* asyncGeneratorForThrowSuspendedStart() {
  AbortUnreachable();
}
it = asyncGeneratorForReturnSuspendedStart();
assertThrowsAsync(() => it.throw(new MyError("throw1")), MyError, "throw1");
assertEqualsAsync({ value: undefined, done: true }, () => it.next("x"));
assertEqualsAsync({ value: "nores", done: true },
                  () => it.return("nores"));
assertThrowsAsync(() => it.throw(new MyError("nores")), MyError, "nores");

it = (async function*() {
  AbortUnreachable();
})();
assertThrowsAsync(() => it.throw(new MyError("throw2")), MyError, "throw2");
assertEqualsAsync({ value: undefined, done: true }, () => it.next("x"));
assertEqualsAsync({ value: "nores", done: true },
                  () => it.return("nores"));
assertThrowsAsync(() => it.throw(new MyError("nores")), MyError, "nores");

it = ({
  async* method() {
    AbortUnreachable();
  }
}).method();
assertThrowsAsync(() => it.throw(new MyError("throw3")), MyError, "throw3");
assertEqualsAsync({ value: undefined, done: true }, () => it.next("x"));
assertEqualsAsync({ value: "nores", done: true },
                  () => it.return("nores"));
assertThrowsAsync(() => it.throw(new MyError("nores")), MyError, "nores");

it = (AsyncGeneratorFunction(`AbortUnreachable()`))();
assertThrowsAsync(() => it.throw(new MyError("throw4")), MyError, "throw4");
assertEqualsAsync({ value: undefined, done: true }, () => it.next("x"));
assertEqualsAsync({ value: "nores", done: true },
                  () => it.return("nores"));
assertThrowsAsync(() => it.throw(new MyError("nores")), MyError, "nores");

it = (AsyncGeneratorFunction(`AbortUnreachable();`))();
assertThrowsAsync(() => it.throw(new MyError("throw5")), MyError, "throw5");
assertEqualsAsync({ value: undefined, done: true }, () => it.next("x"));
assertEqualsAsync({ value: "nores", done: true },
                  () => it.return("nores"));
assertThrowsAsync(() => it.throw(new MyError("nores")), MyError, "nores");

// ----------------------------------------------------------------------------
// Simple yield*:

log = [];
async function* asyncGeneratorYieldStar1() {
  yield* {
    get [Symbol.asyncIterator]() {
      log.push({ name: "get @@asyncIterator" });
      return (...args) => {
        log.push({ name: "call @@asyncIterator", args });
        return this;
      };
    },
    get [Symbol.iterator]() {
      log.push({ name: "get @@iterator" });
      return (...args) => {
        log.push({ name: "call @@iterator", args });
        return this;
      }
    },
    get next() {
      log.push({ name: "get next" });
      return (...args) => {
        log.push({ name: "call next", args });
        return {
          get then() {
            log.push({ name: "get then" });
            return null;
          },
          get value() {
            log.push({ name: "get value" });
            throw (exception = new MyError("AbruptValue!"));
          },
          get done() {
            log.push({ name: "get done" });
            return false;
          }
        };
      }
    },
    get return() {
      log.push({ name: "get return" });
      return (...args) => {
        log.push({ name: "call return", args });
        return { value: args[0], done: true };
      }
    },
    get throw() {
      log.push({ name: "get throw" });
      return (...args) => {
        log.push({ name: "call throw", args });
        throw args[0];
      };
    },
  };
}

it = asyncGeneratorYieldStar1();
assertThrowsAsync(() => it.next(), MyError);
assertEquals([
  { name: "get @@asyncIterator" },
  { name: "call @@asyncIterator", args: [] },
  { name: "get next" },
  { name: "call next", args: [undefined] },
  { name: "get then" },
  { name: "get done" },
  { name: "get value" },
], log);
assertEqualsAsync({ value: undefined, done: true }, () => it.next());