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

mojo/public/dart/third_party/test/lib/src/runner/engine.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.runner.engine;
+
+import 'dart:async';
+import 'dart:collection';
+
+import 'package:async/async.dart' hide Result;
+import 'package:collection/collection.dart';
+import 'package:pool/pool.dart';
+
+import '../backend/live_test.dart';
+import '../backend/live_test_controller.dart';
+import '../backend/state.dart';
+import '../backend/test.dart';
+import 'load_suite.dart';
+import 'runner_suite.dart';
+
+/// An [Engine] manages a run that encompasses multiple test suites.
+///
+/// Test suites are provided by passing them into [suiteSink]. Once all suites
+/// have been provided, the user should close [suiteSink] to indicate this.
+/// [run] won't terminate until [suiteSink] is closed. Suites will be run in the
+/// order they're provided to [suiteSink]. Tests within those suites will
+/// likewise be run in the order of [Suite.tests].
+///
+/// The current status of every test is visible via [liveTests]. [onTestStarted]
+/// can also be used to be notified when a test is about to be run.
+///
+/// The engine has some special logic for [LoadSuite]s and the tests they
+/// contain, referred to as "load tests". Load tests exist to provide visibility
+/// into the process of loading test files, but as long as that process is
+/// proceeding normally users usually don't care about it, so the engine only
+/// surfaces running load tests (that is, includes them in [liveTests] and other
+/// collections) under specific circumstances.
+///
+/// If only load tests are running, exactly one load test will be in [active]
+/// and [liveTests]. If this test passes, it will be removed from both [active]
+/// and [liveTests] and *will not* be added to [passed]. If at any point a load
+/// test fails, it will be added to [failed] and [liveTests].
+///
+/// The test suite loaded by a load suite will be automatically be run by the
+/// engine; it doesn't need to be added to [suiteSink] manually.
+///
+/// Load tests will always be emitted through [onTestStarted] so users can watch
+/// their event streams once they start running.
+class Engine {
+  /// Whether [run] has been called yet.
+  var _runCalled = false;
+
+  /// Whether [close] has been called.
+  var _closed = false;
+
+  /// Whether [close] was called before all the tests finished running.
+  ///
+  /// This is `null` if close hasn't been called and the tests are still
+  /// running, `true` if close was called before the tests finished running, and
+  /// `false` if the tests finished running before close was called.
+  var _closedBeforeDone;
+
+  /// A pool that limits the number of test suites running concurrently.
+  final Pool _runPool;
+
+  /// A pool that limits the number of test suites loaded concurrently.
+  ///
+  /// Once this reaches its limit, loading any additional test suites will cause
+  /// previous suites to be unloaded in the order they completed.
+  final Pool _loadPool;
+
+  /// Whether all tests passed.
+  ///
+  /// This fires once all tests have completed and [suiteSink] has been closed.
+  /// This will be `null` if [close] was called before all the tests finished
+  /// running.
+  Future<bool> get success async {
+    await _group.future;
+    if (_closedBeforeDone) return null;
+    return liveTests.every((liveTest) =>
+        liveTest.state.result == Result.success);
+  }
+
+  /// A group of futures for each test suite.
+  final _group = new FutureGroup();
+
+  /// A sink used to pass [RunnerSuite]s in to the engine to run.
+  ///
+  /// Suites may be added as quickly as they're available; the Engine will only
+  /// run as many as necessary at a time based on its concurrency settings.
+  ///
+  /// Suites added to the sink will be closed by the engine based on its
+  /// internal logic.
+  Sink<RunnerSuite> get suiteSink => new DelegatingSink(_suiteController.sink);
+  final _suiteController = new StreamController<RunnerSuite>();
+
+  /// All the currently-known tests that have run, are running, or will run.
+  ///
+  /// These are [LiveTest]s, representing the in-progress state of each test.
+  /// Tests that have not yet begun running are marked [Status.pending]; tests
+  /// that have finished are marked [Status.complete].
+  ///
+  /// This is guaranteed to contain the same tests as the union of [passed],
+  /// [skipped], [failed], and [active].
+  ///
+  /// [LiveTest.run] must not be called on these tests.
+  List<LiveTest> get liveTests => new UnmodifiableListView(_liveTests);
+  final _liveTests = new List<LiveTest>();
+
+  /// A stream that emits each [LiveTest] as it's about to start running.
+  ///
+  /// This is guaranteed to fire before [LiveTest.onStateChange] first fires.
+  Stream<LiveTest> get onTestStarted => _onTestStartedController.stream;
+  final _onTestStartedController = new StreamController<LiveTest>.broadcast();
+
+  /// The set of tests that have completed and been marked as passing.
+  Set<LiveTest> get passed => new UnmodifiableSetView(_passed);
+  final _passed = new Set<LiveTest>();
+
+  /// The set of tests that have completed and been marked as skipped.
+  Set<LiveTest> get skipped => new UnmodifiableSetView(_skipped);
+  final _skipped = new Set<LiveTest>();
+
+  /// The set of tests that have completed and been marked as failing or error.
+  Set<LiveTest> get failed => new UnmodifiableSetView(_failed);
+  final _failed = new Set<LiveTest>();
+
+  /// The tests that are still running, in the order they begain running.
+  List<LiveTest> get active => new UnmodifiableListView(_active);
+  final _active = new QueueList<LiveTest>();
+
+  /// The tests from [LoadSuite]s that are still running, in the order they
+  /// began running.
+  ///
+  /// This is separate from [active] because load tests aren't always surfaced.
+  final _activeLoadTests = new List<LiveTest>();
+
+  /// Whether this engine is idle—that is, not currently executing a test.
+  bool get isIdle => _group.isIdle;
+
+  /// A broadcast stream that fires an event whenever [isIdle] switches from
+  /// `false` to `true`.
+  Stream get onIdle => _group.onIdle;
+
+  /// Creates an [Engine] that will run all tests provided via [suiteSink].
+  ///
+  /// [concurrency] controls how many suites are run at once, and defaults to 1.
+  /// [maxSuites] controls how many suites are *loaded* at once, and defaults to
+  /// four times [concurrency].
+  Engine({int concurrency, int maxSuites})
+      : _runPool = new Pool(concurrency == null ? 1 : concurrency),
+        _loadPool = new Pool(maxSuites == null
+            ? (concurrency == null ? 2 : concurrency * 2)
+            : maxSuites) {
+    _group.future.then((_) {
+      if (_closedBeforeDone == null) _closedBeforeDone = false;
+    }).catchError((_) {
+      // Don't top-level errors. They'll be thrown via [success] anyway.
+    });
+  }
+
+  /// Creates an [Engine] that will run all tests in [suites].
+  ///
+  /// [concurrency] controls how many suites are run at once. An engine
+  /// constructed this way will automatically close its [suiteSink], meaning
+  /// that no further suites may be provided.
+  factory Engine.withSuites(List<RunnerSuite> suites, {int concurrency}) {
+    var engine = new Engine(concurrency: concurrency);
+    for (var suite in suites) engine.suiteSink.add(suite);
+    engine.suiteSink.close();
+    return engine;
+  }
+
+  /// Runs all tests in all suites defined by this engine.
+  ///
+  /// This returns `true` if all tests succeed, and `false` otherwise. It will
+  /// only return once all tests have finished running and [suiteSink] has been
+  /// closed.
+  Future<bool> run() {
+    if (_runCalled) {
+      throw new StateError("Engine.run() may not be called more than once.");
+    }
+    _runCalled = true;
+
+    _suiteController.stream.listen((suite) {
+      _group.add(new Future.sync(() async {
+        var loadResource = await _loadPool.request();
+
+        if (suite is LoadSuite) {
+          suite = await _addLoadSuite(suite);
+          if (suite == null) {
+            loadResource.release();
+            return;
+          }
+        }
+
+        await _runPool.withResource(() async {
+          if (_closed) return null;
+
+          // TODO(nweiz): Use a real for loop when issue 23394 is fixed.
+          await Future.forEach(suite.tests, (test) async {
+            if (_closed) return;
+
+            var liveTest = test.metadata.skip
+                ? _skippedTest(suite, test)
+                : test.load(suite);
+            _liveTests.add(liveTest);
+            _active.add(liveTest);
+
+            // If there were no active non-load tests, the current active test
+            // would have been a load test. In that case, remove it, since now we
+            // have a non-load test to add.
+            if (_active.isNotEmpty && _active.first.suite is LoadSuite) {
+              _liveTests.remove(_active.removeFirst());
+            }
+
+            liveTest.onStateChange.listen((state) {
+              if (state.status != Status.complete) return;
+              _active.remove(liveTest);
+
+              // If we're out of non-load tests, surface a load test.
+              if (_active.isEmpty && _activeLoadTests.isNotEmpty) {
+                _active.add(_activeLoadTests.first);
+                _liveTests.add(_activeLoadTests.first);
+              }
+
+              if (state.result != Result.success) {
+                _passed.remove(liveTest);
+                _failed.add(liveTest);
+              } else if (liveTest.test.metadata.skip) {
+                _skipped.add(liveTest);
+              } else {
+                _passed.add(liveTest);
+              }
+            });
+
+            _onTestStartedController.add(liveTest);
+
+            // First, schedule a microtask to ensure that [onTestStarted] fires
+            // before the first [LiveTest.onStateChange] event. Once the test
+            // finishes, use [new Future] to do a coarse-grained event loop pump
+            // to avoid starving non-microtask events.
+            await new Future.microtask(liveTest.run);
+            await new Future(() {});
+          });
+
+          loadResource.allowRelease(() => suite.close());
+        });
+      }));
+    }, onDone: _group.close);
+
+    return success;
+  }
+
+  /// Returns a dummy [LiveTest] for a test marked as "skip".
+  LiveTest _skippedTest(RunnerSuite suite, Test test) {
+    var controller;
+    controller = new LiveTestController(suite, test, () {
+      controller.setState(const State(Status.running, Result.success));
+      controller.setState(const State(Status.complete, Result.success));
+      controller.completer.complete();
+    }, () {});
+    return controller.liveTest;
+  }
+
+  /// Adds listeners for [suite].
+  ///
+  /// Load suites have specific logic apart from normal test suites.
+  Future<RunnerSuite> _addLoadSuite(LoadSuite suite) async {
+    var liveTest = await suite.tests.single.load(suite);
+
+    _activeLoadTests.add(liveTest);
+
+    // Only surface the load test if there are no other tests currently running.
+    if (_active.isEmpty) {
+      _liveTests.add(liveTest);
+      _active.add(liveTest);
+    }
+
+    liveTest.onStateChange.listen((state) {
+      if (state.status != Status.complete) return;
+      _activeLoadTests.remove(liveTest);
+
+      // Only one load test will be active at any given time, and it will always
+      // be the only active test. Remove it and, if possible, surface another
+      // load test.
+      if (_active.isNotEmpty && _active.first.suite == suite) {
+        _active.remove(liveTest);
+        _liveTests.remove(liveTest);
+
+        if (_activeLoadTests.isNotEmpty) {
+          _active.add(_activeLoadTests.last);
+          _liveTests.add(_activeLoadTests.last);
+        }
+      }
+
+      // Surface the load test if it fails so that the user can see the failure.
+      if (state.result == Result.success) return;
+      _failed.add(liveTest);
+      _liveTests.add(liveTest);
+    });
+
+    // Run the test immediately. We don't want loading to be blocked on suites
+    // that are already running.
+    _onTestStartedController.add(liveTest);
+    await liveTest.run();
+
+    return suite.suite;
+  }
+
+  /// Signals that the caller is done paying attention to test results and the
+  /// engine should release any resources it has allocated.
+  ///
+  /// Any actively-running tests are also closed. VM tests are allowed to finish
+  /// running so that any modifications they've made to the filesystem can be
+  /// cleaned up.
+  ///
+  /// **Note that closing the engine is not the same as closing [suiteSink].**
+  /// Closing [suiteSink] indicates that no more input will be provided, closing
+  /// the engine indicates that no more output should be emitted.
+  Future close() async {
+    _closed = true;
+    if (_closedBeforeDone == null) _closedBeforeDone = true;
+    _suiteController.close();
+
+    // Close the running tests first so that we're sure to wait for them to
+    // finish before we close their suites and cause them to become unloaded.
+    var allLiveTests = liveTests.toSet()..addAll(_activeLoadTests);
+    await Future.wait(allLiveTests.map((liveTest) => liveTest.close()));
+
+    var allSuites = allLiveTests.map((liveTest) => liveTest.suite).toSet();
+    await Future.wait(allSuites.map((suite) => suite.close()));
+  }
+}