Improve test coverage (#7564)

Also, fix some minor bugs with SynchronousFuture.

packages/flutter/lib/src/foundation/synchronous_future.dart

@@ -42,7 +42,9 @@ class SynchronousFuture<T> implements Future<T> {
   }
 
   @override
-  Future<T> timeout(Duration timeLimit, { dynamic onTimeout() }) => new Completer<T>().future;
+  Future<T> timeout(Duration timeLimit, { dynamic onTimeout() }) {
+    return new Future<T>.value(_value).timeout(timeLimit, onTimeout: onTimeout);
+  }
 
   @override
   Future<T> whenComplete(dynamic action()) {

packages/flutter/lib/src/material/button.dart

@@ -230,6 +230,7 @@ class _MaterialButtonState extends State<MaterialButton> {
           }
       }
     } else {
+      assert(_colorBrightness != null);
       switch (_colorBrightness) {
         case Brightness.light:
           return Colors.black26;
@@ -237,7 +238,6 @@ class _MaterialButtonState extends State<MaterialButton> {
           return Colors.white30;
       }
     }
-    assert(_colorBrightness != null);
     return null;
   }
 

packages/flutter/test/animation/animation_controller_test.dart

@@ -269,4 +269,18 @@ void main() {
     controller.dispose();
     expect(controller, hasOneLineDescription);
   });
+
+  test('AnimationController error handling', () {
+    AnimationController controller = new AnimationController(
+      vsync: const TestVSync(),
+    );
+
+    expect(controller.forward, throwsFlutterError);
+    expect(controller.reverse, throwsFlutterError);
+    expect(() { controller.animateTo(0.5); }, throwsFlutterError);
+    expect(controller.repeat, throwsFlutterError);
+
+    controller.dispose();
+    expect(controller.dispose, throwsFlutterError);
+  });
 }

packages/flutter/test/animation/animations_test.dart

@@ -6,6 +6,11 @@ import 'package:flutter_test/flutter_test.dart';
 import 'package:flutter/animation.dart';
 import 'package:flutter/widgets.dart';
 
+class BogusCurve extends Curve {
+  @override
+  double transform(double t) => 100.0;
+}
+
 void main() {
   setUp(() {
     WidgetsFlutterBinding.ensureInitialized();
@@ -113,7 +118,6 @@ void main() {
     expect(animation.toString(), contains('no next'));
   });
 
-
   test('AnimationMean control test', () {
     AnimationController left = new AnimationController(
       value: 0.5,
@@ -148,4 +152,13 @@ void main() {
     expect(mean.value, equals(0.50));
     expect(log, isEmpty);
   });
+
+  test('CurvedAnimation with bogus curve', () {
+    AnimationController controller = new AnimationController(
+      vsync: const TestVSync(),
+    );
+    CurvedAnimation curved = new CurvedAnimation(parent: controller, curve: new BogusCurve());
+
+    expect(() { curved.value; }, throwsFlutterError);
+  });
 }

packages/flutter/test/foundation/caching_iterable_test.dart

@@ -90,4 +90,21 @@ void main() {
     expect(integers, equals(<int>[1, 2, 3, 4, 5]));
     expect(yieldCount, equals(5));
   });
+
+  test('The Caching Iterable: expand', () {
+    Iterable<int> integers = new CachingIterable<int>(range(1, 5).iterator);
+    expect(yieldCount, equals(0));
+
+    Iterable<int> expanded1 = integers.expand((int i) => <int>[i, i]);
+
+    expect(yieldCount, equals(0));
+    expect(expanded1, equals(<int>[1, 1, 2, 2, 3, 3, 4, 4, 5, 5]));
+    expect(yieldCount, equals(5));
+
+    Iterable<int> expanded2 = integers.expand((int i) => <int>[i, i]);
+
+    expect(yieldCount, equals(5));
+    expect(expanded2, equals(<int>[1, 1, 2, 2, 3, 3, 4, 4, 5, 5]));
+    expect(yieldCount, equals(5));
+  });
 }

packages/flutter/test/foundation/synchronous_future_test.dart

+// Copyright 2017 The Chromium Authors. 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:flutter/foundation.dart';
+import 'package:test/test.dart';
+
+void main() {
+  test('SynchronousFuture control test', () async {
+    Future<int> future = new SynchronousFuture<int>(42);
+
+    int result;
+    future.then((int value) { result = value; });
+
+    expect(result, equals(42));
+    result = null;
+
+    Future<int> futureWithTimeout = future.timeout(const Duration(milliseconds: 1));
+    futureWithTimeout.then((int value) { result = value; });
+    expect(result, isNull);
+    await futureWithTimeout;
+    expect(result, equals(42));
+    result = null;
+
+    Stream<int> stream = future.asStream();
+
+    expect(await stream.single, equals(42));
+
+    bool ranAction = false;
+    Future<int> completeResult = future.whenComplete(() {
+      ranAction = true;
+      return new Future<int>.value(31);
+    });
+
+    expect(ranAction, isTrue);
+    ranAction = false;
+
+    expect(await completeResult, equals(42));
+
+    Object exception;
+    try {
+      await future.whenComplete(() {
+        throw null;
+      });
+      // Unreached.
+      expect(false, isTrue);
+    } catch (e) {
+      exception = e;
+    }
+    expect(exception, isNullThrownError);
+  });
+}

packages/flutter/test/material/icon_theme_data_test.dart

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  test('IconThemeData control test', () {
+    IconThemeData data = new IconThemeData(color: Colors.green[500], opacity: 0.5, size: 16.0);
+
+    expect(data, hasOneLineDescription);
+    expect(data, equals(data.copyWith()));
+    expect(data.hashCode, equals(data.copyWith().hashCode));
+
+    IconThemeData lerped = IconThemeData.lerp(data, const IconThemeData.fallback(), 0.25);
+    expect(lerped.color, equals(Color.lerp(Colors.green[500], Colors.black, 0.25)));
+    expect(lerped.opacity, equals(0.625));
+    expect(lerped.size, equals(18.0));
+  });
+}

packages/flutter/test/material/theme_data_test.dart

@@ -6,6 +6,20 @@ import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 void main() {
+  test('Theme data control test', () {
+    ThemeData dark = new ThemeData.dark();
+
+    expect(dark, hasOneLineDescription);
+    expect(dark, equals(dark.copyWith()));
+    expect(dark.hashCode, equals(dark.copyWith().hashCode));
+
+    ThemeData light = new ThemeData.light();
+    ThemeData dawn = ThemeData.lerp(dark, light, 0.25);
+
+    expect(dawn.brightness, Brightness.dark);
+    expect(dawn.primaryColor, Color.lerp(dark.primaryColor, light.primaryColor, 0.25));
+  });
+
   test('Defaults to the default typography for the platform', () {
     for (TargetPlatform platform in TargetPlatform.values) {
       ThemeData theme = new ThemeData(platform: platform);

packages/flutter/test/scheduler/priority_test.dart

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:flutter/scheduler.dart';
+import 'package:test/test.dart';
+
+void main() {
+  test('Priority operators control test', () async {
+    Priority priority = Priority.idle + (Priority.kMaxOffset + 100);
+    expect(priority.value, equals(Priority.idle.value + Priority.kMaxOffset));
+
+    priority = Priority.animation - (Priority.kMaxOffset + 100);
+    expect(priority.value, equals(Priority.animation.value - Priority.kMaxOffset));
+  });
+}

packages/flutter/test/scheduler/ticker_test.dart

@@ -23,6 +23,8 @@ void main() {
     expect(ticker.isActive, isTrue);
     expect(tickCount, equals(0));
 
+    expect(ticker.start, throwsFlutterError);
+
     await tester.pump(const Duration(milliseconds: 10));
 
     expect(tickCount, equals(1));