Roll Observatory packages and add a roll script

packages/observe/test/observe_test.dart

+// Copyright (c) 2013, 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.
+
+import 'dart:async';
+import 'package:logging/logging.dart';
+import 'package:observe/observe.dart';
+import 'package:observe/src/dirty_check.dart' as dirty_check;
+import 'package:unittest/unittest.dart';
+import 'observe_test_utils.dart';
+
+import 'package:observe/mirrors_used.dart'; // make test smaller.
+import 'package:smoke/mirrors.dart';
+
+main() {
+  useMirrors();
+  dirtyCheckZone().run(_tests);
+}
+
+void _tests() {
+  // Note: to test the basic Observable system, we use ObservableBox due to its
+  // simplicity. We also test a variant that is based on dirty-checking.
+
+  test('no observers at the start', () {
+    expect(dirty_check.allObservablesCount, 0);
+  });
+
+  group('WatcherModel', () => _observeTests((x) => new WatcherModel(x)));
+
+  group('ObservableBox', () => _observeTests((x) => new ObservableBox(x)));
+
+  group('ModelSubclass', () => _observeTests((x) => new ModelSubclass(x)));
+
+  group('dirtyCheck loops can be debugged', () {
+    var messages;
+    var subscription;
+    setUp(() {
+      messages = [];
+      subscription = Logger.root.onRecord.listen((record) {
+        messages.add(record.message);
+      });
+    });
+
+    tearDown(() {
+      subscription.cancel();
+    });
+
+    test('logs debug information', () {
+      var maxNumIterations = dirty_check.MAX_DIRTY_CHECK_CYCLES;
+
+      var x = new WatcherModel(0);
+      var sub = x.changes.listen(expectAsync((_) { x.value++; },
+          count: maxNumIterations));
+      x.value = 1;
+      Observable.dirtyCheck();
+      expect(x.value, maxNumIterations + 1);
+      expect(messages.length, 2);
+
+      expect(messages[0], contains('Possible loop'));
+      expect(messages[1], contains('index 0'));
+      expect(messages[1], contains('object: $x'));
+
+      sub.cancel();
+    });
+  });
+}
+
+void _observeTests(createModel(x)) {
+  final watch = createModel(null) is! ChangeNotifier;
+
+  // Track the subscriptions so we can clean them up in tearDown.
+  List subs;
+
+  int initialObservers;
+  setUp(() {
+    initialObservers = dirty_check.allObservablesCount;
+    subs = [];
+
+    if (watch) scheduleMicrotask(Observable.dirtyCheck);
+  });
+
+  tearDown(() {
+    for (var sub in subs) sub.cancel();
+    return new Future(() {
+      expect(dirty_check.allObservablesCount, initialObservers,
+          reason: 'Observable object leaked');
+    });
+  });
+
+  test('handle future result', () {
+    var callback = expectAsync((){});
+    return new Future(callback);
+  });
+
+  test('no observers', () {
+    var t = createModel(123);
+    expect(t.value, 123);
+    t.value = 42;
+    expect(t.value, 42);
+    expect(t.hasObservers, false);
+  });
+
+  test('listen adds an observer', () {
+    var t = createModel(123);
+    expect(t.hasObservers, false);
+
+    subs.add(t.changes.listen((n) {}));
+    expect(t.hasObservers, true);
+  });
+
+  test('changes delived async', () {
+    var t = createModel(123);
+    int called = 0;
+
+    subs.add(t.changes.listen(expectAsync((records) {
+      called++;
+      expectPropertyChanges(records, watch ? 1 : 2);
+    })));
+
+    t.value = 41;
+    t.value = 42;
+    expect(called, 0);
+  });
+
+  test('cause changes in handler', () {
+    var t = createModel(123);
+    int called = 0;
+
+    subs.add(t.changes.listen(expectAsync((records) {
+      called++;
+      expectPropertyChanges(records, 1);
+      if (called == 1) {
+        // Cause another change
+        t.value = 777;
+      }
+    }, count: 2)));
+
+    t.value = 42;
+  });
+
+  test('multiple observers', () {
+    var t = createModel(123);
+
+    verifyRecords(records) {
+      expectPropertyChanges(records, watch ? 1 : 2);
+    };
+
+    subs.add(t.changes.listen(expectAsync(verifyRecords)));
+    subs.add(t.changes.listen(expectAsync(verifyRecords)));
+
+    t.value = 41;
+    t.value = 42;
+  });
+
+  test('async processing model', () {
+    var t = createModel(123);
+    var records = [];
+    subs.add(t.changes.listen((r) { records.addAll(r); }));
+    t.value = 41;
+    t.value = 42;
+    expectChanges(records, [], reason: 'changes delived async');
+
+    return new Future(() {
+      expectPropertyChanges(records, watch ? 1 : 2);
+      records.clear();
+
+      t.value = 777;
+      expectChanges(records, [], reason: 'changes delived async');
+
+    }).then(newMicrotask).then((_) {
+      expectPropertyChanges(records, 1);
+
+      // Has no effect if there are no changes
+      Observable.dirtyCheck();
+      expectPropertyChanges(records, 1);
+    });
+  });
+
+  test('cancel listening', () {
+    var t = createModel(123);
+    var sub;
+    sub = t.changes.listen(expectAsync((records) {
+      expectPropertyChanges(records, 1);
+      sub.cancel();
+      t.value = 777;
+      scheduleMicrotask(Observable.dirtyCheck);
+    }));
+    t.value = 42;
+  });
+
+  test('cancel and reobserve', () {
+    var t = createModel(123);
+    var sub;
+    sub = t.changes.listen(expectAsync((records) {
+      expectPropertyChanges(records, 1);
+      sub.cancel();
+
+      scheduleMicrotask(expectAsync(() {
+        subs.add(t.changes.listen(expectAsync((records) {
+          expectPropertyChanges(records, 1);
+        })));
+        t.value = 777;
+        scheduleMicrotask(Observable.dirtyCheck);
+      }));
+    }));
+    t.value = 42;
+  });
+
+  test('cannot modify changes list', () {
+    var t = createModel(123);
+    var records = null;
+    subs.add(t.changes.listen((r) { records = r; }));
+    t.value = 42;
+
+    return new Future(() {
+      expectPropertyChanges(records, 1);
+
+      // Verify that mutation operations on the list fail:
+
+      expect(() {
+        records[0] = new PropertyChangeRecord(t, #value, 0, 1);
+      }, throwsUnsupportedError);
+
+      expect(() { records.clear(); }, throwsUnsupportedError);
+
+      expect(() { records.length = 0; }, throwsUnsupportedError);
+    });
+  });
+
+  test('notifyChange', () {
+    var t = createModel(123);
+    var records = [];
+    subs.add(t.changes.listen((r) { records.addAll(r); }));
+    t.notifyChange(new PropertyChangeRecord(t, #value, 123, 42));
+
+    return new Future(() {
+      expectPropertyChanges(records, 1);
+      expect(t.value, 123, reason: 'value did not actually change.');
+    });
+  });
+
+  test('notifyPropertyChange', () {
+    var t = createModel(123);
+    var records = null;
+    subs.add(t.changes.listen((r) { records = r; }));
+    expect(t.notifyPropertyChange(#value, t.value, 42), 42,
+        reason: 'notifyPropertyChange returns newValue');
+
+    return new Future(() {
+      expectPropertyChanges(records, 1);
+      expect(t.value, 123, reason: 'value did not actually change.');
+    });
+  });
+}
+
+expectPropertyChanges(records, int number) {
+  expect(records.length, number, reason: 'expected $number change records');
+  for (var record in records) {
+    expect(record is PropertyChangeRecord, true, reason:
+        'record should be PropertyChangeRecord');
+    expect((record as PropertyChangeRecord).name, #value, reason:
+        'record should indicate a change to the "value" property');
+  }
+}
+
+// A test model based on dirty checking.
+class WatcherModel<T> extends Observable {
+  @observable T value;
+
+  WatcherModel([T initialValue]) : value = initialValue;
+
+  String toString() => '#<$runtimeType value: $value>';
+}
+
+class ModelSubclass<T> extends WatcherModel<T> {
+  ModelSubclass([T initialValue]) : super(initialValue);
+}