Automatically step past async state-machine switch for 'anext'.

runtime/observatory/tests/service/async_step_test.dart

-// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-// VMOptions=--compile_all --error_on_bad_type --error_on_bad_override  --verbose_debug
-
-import 'package:observatory/service_io.dart';
-import 'package:unittest/unittest.dart';
-import 'test_helper.dart';
-import 'dart:developer';
-
-foo() async { }
-
-doAsync(stop) async {
-  if (stop) debugger();
-  await foo(); // Line 15.
-  await foo(); // Line 16.
-  await foo(); // Line 17.
-  return null;
-}
-
-testMain() {
-  // With two runs of doAsync floating around, async step should only cause
-  // us to stop in the run we started in.
-  doAsync(false);
-  doAsync(true);
-}
-
-asyncStep(Isolate isolate) async {
-  await isolate.reload(); // isolate.pauseEvent may be stale
-  ServiceEvent event = isolate.pauseEvent;
-  print("Pause event is $event");
-  expect(event, isNotNull);
-  expect(event.kind, equals(ServiceEvent.kPauseBreakpoint));
-
-  // 1. Set breakpoint for the continuation and resume the isolate.
-  Instance continuation = event.asyncContinuation;
-  print("Async continuation is $continuation");
-  if (continuation == null) {
-    print(await isolate.getStack());
-  }
-  expect(continuation.isClosure, isTrue);
-
-  var bpt = await isolate.addBreakOnActivation(continuation);
-  print("Async step to $bpt");
-  expect(bpt is Breakpoint, isTrue);
-
-  await isolate.resume();
-  await hasStoppedAtBreakpoint(isolate);
-  print("Big step to: ${isolate.pauseEvent}");
-
-  // 2. Step past the state-machine dispatch.
-  await isolate.stepOver();
-  await hasStoppedAtBreakpoint(isolate);
-  print("Small step to: ${isolate.pauseEvent}");
-}
-
-var tests = [
-  hasStoppedAtBreakpoint,
-  stoppedAtLine(15),
-  asyncStep,
-  stoppedAtLine(16),
-  asyncStep,
-  stoppedAtLine(17),
-  resumeIsolate,
-];
-
-main(args) => runIsolateTests(args, tests, testeeConcurrent: testMain);