Stop running pub get at gclient sync time and fix build bugs

mojo/public/dart/third_party/test/lib/src/backend/invoker.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.
+
+library test.backend.invoker;
+
+import 'dart:async';
+
+import 'package:stack_trace/stack_trace.dart';
+
+import '../frontend/expect.dart';
+import '../utils.dart';
+import 'closed_exception.dart';
+import 'live_test.dart';
+import 'live_test_controller.dart';
+import 'metadata.dart';
+import 'outstanding_callback_counter.dart';
+import 'state.dart';
+import 'suite.dart';
+import 'test.dart';
+
+/// A test in this isolate.
+class LocalTest implements Test {
+  final String name;
+  final Metadata metadata;
+
+  /// The test body.
+  final AsyncFunction _body;
+
+  /// The callback used to clean up after the test.
+  ///
+  /// This is separated out from [_body] because it needs to run once the test's
+  /// asynchronous computation has finished, even if that's different from the
+  /// completion of the main body of the test.
+  final AsyncFunction _tearDown;
+
+  LocalTest(this.name, this.metadata, body(), {tearDown()})
+      : _body = body,
+        _tearDown = tearDown;
+
+  /// Loads a single runnable instance of this test.
+  LiveTest load(Suite suite) {
+    var invoker = new Invoker._(suite, this);
+    return invoker.liveTest;
+  }
+
+  Test change({String name, Metadata metadata}) {
+    if (name == name && metadata == this.metadata) return this;
+    if (name == null) name = this.name;
+    if (metadata == null) metadata = this.metadata;
+    return new LocalTest(name, metadata, _body, tearDown: _tearDown);
+  }
+}
+
+/// The class responsible for managing the lifecycle of a single local test.
+///
+/// The current invoker is accessible within the zone scope of the running test
+/// using [Invoker.current]. It's used to track asynchronous callbacks and
+/// report asynchronous errors.
+class Invoker {
+  /// The live test being driven by the invoker.
+  ///
+  /// This provides a view into the state of the test being executed.
+  LiveTest get liveTest => _controller.liveTest;
+  LiveTestController _controller;
+
+  /// Whether the test has been closed.
+  ///
+  /// Once the test is closed, [expect] and [expectAsync] will throw
+  /// [ClosedException]s whenever accessed to help the test stop executing as
+  /// soon as possible.
+  bool get closed => _onCloseCompleter.isCompleted;
+
+  /// A future that completes once the test has been closed.
+  Future get onClose => _onCloseCompleter.future;
+  final _onCloseCompleter = new Completer();
+
+  /// The test being run.
+  LocalTest get _test => liveTest.test as LocalTest;
+
+  /// The test metadata merged with the suite metadata.
+  final Metadata metadata;
+
+  /// The outstanding callback counter for the current zone.
+  OutstandingCallbackCounter get _outstandingCallbacks {
+    var counter = Zone.current[this];
+    if (counter != null) return counter;
+    throw new StateError("Can't add or remove outstanding callbacks outside "
+        "of a test body.");
+  }
+
+  /// The current invoker, or `null` if none is defined.
+  ///
+  /// An invoker is only set within the zone scope of a running test.
+  static Invoker get current {
+    // TODO(nweiz): Use a private symbol when dart2js supports it (issue 17526).
+    return Zone.current[#test.invoker];
+  }
+
+  /// The zone that the top level of [_test.body] is running in.
+  ///
+  /// Tracking this ensures that [_timeoutTimer] isn't created in a
+  /// timer-mocking zone created by the test.
+  Zone _invokerZone;
+
+  /// The timer for tracking timeouts.
+  ///
+  /// This will be `null` until the test starts running.
+  Timer _timeoutTimer;
+
+  Invoker._(Suite suite, LocalTest test)
+      : metadata = suite.metadata.merge(test.metadata) {
+    _controller = new LiveTestController(
+        suite, test, _onRun, _onCloseCompleter.complete);
+  }
+
+  /// Tells the invoker that there's a callback running that it should wait for
+  /// before considering the test successful.
+  ///
+  /// Each call to [addOutstandingCallback] should be followed by a call to
+  /// [removeOutstandingCallback] once the callbak is no longer running. Note
+  /// that only successful tests wait for outstanding callbacks; as soon as a
+  /// test experiences an error, any further calls to [addOutstandingCallback]
+  /// or [removeOutstandingCallback] will do nothing.
+  ///
+  /// Throws a [ClosedException] if this test has been closed.
+  void addOutstandingCallback() {
+    if (closed) throw new ClosedException();
+    _outstandingCallbacks.addOutstandingCallback();
+  }
+
+  /// Tells the invoker that a callback declared with [addOutstandingCallback]
+  /// is no longer running.
+  void removeOutstandingCallback() {
+    heartbeat();
+    _outstandingCallbacks.removeOutstandingCallback();
+  }
+
+  /// Removes all outstanding callbacks, for example when an error occurs.
+  ///
+  /// Future calls to [addOutstandingCallback] and [removeOutstandingCallback]
+  /// will be ignored.
+  void removeAllOutstandingCallbacks() =>
+      _outstandingCallbacks.removeAllOutstandingCallbacks();
+
+  /// Runs [fn] and returns once all (registered) outstanding callbacks it
+  /// transitively invokes have completed.
+  ///
+  /// If [fn] itself returns a future, this will automatically wait until that
+  /// future completes as well.
+  ///
+  /// Note that outstanding callbacks registered within [fn] will *not* be
+  /// registered as outstanding callback outside of [fn].
+  Future waitForOutstandingCallbacks(fn()) {
+    heartbeat();
+
+    var counter = new OutstandingCallbackCounter();
+    runZoned(() {
+      // TODO(nweiz): Use async/await here once issue 23497 has been fixed in
+      // two stable versions.
+      new Future.sync(fn).then((_) => counter.removeOutstandingCallback());
+    }, zoneValues: {
+      // Use the invoker as a key so that multiple invokers can have different
+      // outstanding callback counters at once.
+      this: counter
+    });
+
+    return counter.noOutstandingCallbacks;
+  }
+
+  /// Notifies the invoker that progress is being made.
+  ///
+  /// Each heartbeat resets the timeout timer. This helps ensure that
+  /// long-running tests that still make progress don't time out.
+  void heartbeat() {
+    if (liveTest.isComplete) return;
+    if (_timeoutTimer != null) _timeoutTimer.cancel();
+
+    var timeout = metadata.timeout.apply(new Duration(seconds: 30));
+    if (timeout == null) return;
+    _timeoutTimer = _invokerZone.createTimer(timeout,
+        Zone.current.bindCallback(() {
+      if (liveTest.isComplete) return;
+      _handleError(
+          new TimeoutException(
+              "Test timed out after ${niceDuration(timeout)}.", timeout));
+    }));
+  }
+
+  /// Notifies the invoker of an asynchronous error.
+  void _handleError(error, [StackTrace stackTrace]) {
+    if (stackTrace == null) stackTrace = new Chain.current();
+
+    var afterSuccess = liveTest.isComplete &&
+        liveTest.state.result == Result.success;
+
+    if (error is! TestFailure) {
+      _controller.setState(const State(Status.complete, Result.error));
+    } else if (liveTest.state.result != Result.error) {
+      _controller.setState(const State(Status.complete, Result.failure));
+    }
+
+    _controller.addError(error, stackTrace);
+    removeAllOutstandingCallbacks();
+
+    // If a test was marked as success but then had an error, that indicates
+    // that it was poorly-written and could be flaky.
+    if (!afterSuccess) return;
+    _handleError(
+        "This test failed after it had already completed. Make sure to use "
+            "[expectAsync]\n"
+        "or the [completes] matcher when testing async code.",
+        stackTrace);
+  }
+
+  /// The method that's run when the test is started.
+  void _onRun() {
+    _controller.setState(const State(Status.running, Result.success));
+
+    var outstandingCallbacksForBody = new OutstandingCallbackCounter();
+
+    // TODO(nweiz): Use async/await here once issue 23497 has been fixed in two
+    // stable versions.
+    Chain.capture(() {
+      runZonedWithValues(() {
+        _invokerZone = Zone.current;
+
+        heartbeat();
+
+        // Run the test asynchronously so that the "running" state change has
+        // a chance to hit its event handler(s) before the test produces an
+        // error. If an error is emitted before the first state change is
+        // handled, we can end up with [onError] callbacks firing before the
+        // corresponding [onStateChange], which violates the timing
+        // guarantees.
+        new Future(_test._body)
+            .then((_) => removeOutstandingCallback());
+
+        _outstandingCallbacks.noOutstandingCallbacks.then((_) {
+          if (_test._tearDown == null) return null;
+
+          // Reset the outstanding callback counter to wait for callbacks from
+          // the test's `tearDown` to complete.
+          return waitForOutstandingCallbacks(() =>
+              runZoned(_test._tearDown, onError: _handleError));
+        }).then((_) {
+          if (_timeoutTimer != null) _timeoutTimer.cancel();
+          _controller.setState(
+              new State(Status.complete, liveTest.state.result));
+
+          // Use [Timer.run] here to avoid starving the DOM or other
+          // non-microtask events.
+          Timer.run(_controller.completer.complete);
+        });
+      }, zoneValues: {
+        #test.invoker: this,
+        // Use the invoker as a key so that multiple invokers can have different
+        // outstanding callback counters at once.
+        this: outstandingCallbacksForBody
+      },
+          zoneSpecification: new ZoneSpecification(
+              print: (self, parent, zone, line) => _controller.print(line)),
+          onError: _handleError);
+    });
+  }
+}