Index: mojo/public/dart/third_party/test/lib/src/backend/invoker.dart |
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+// 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); |
+ }); |
+ } |
+} |