Improve test coverage and fix bugs (#7410)

This patch improves test coverage for a number of files that had low
coverage. This patch also fixes a few minor bugs found by these tests.

packages/flutter/lib/src/gestures/converter.dart

@@ -289,9 +289,30 @@ class PointerEventConverter {
               tilt: datum.tilt
             );
           }
-          _pointers.remove(datum.device);
           break;
         case ui.PointerChange.remove:
+          assert(_pointers.containsKey(datum.device));
+          _PointerState state = _pointers[datum.device];
+          if (state.down) {
+            yield new PointerCancelEvent(
+              timeStamp: timeStamp,
+              pointer: state.pointer,
+              kind: kind,
+              device: datum.device,
+              position: position,
+              buttons: datum.buttons,
+              obscured: datum.obscured,
+              pressureMin: datum.pressureMin,
+              pressureMax: datum.pressureMax,
+              distance: datum.distance,
+              distanceMax: datum.distanceMax,
+              radiusMin: datum.radiusMin,
+              radiusMax: datum.radiusMax,
+              orientation: datum.orientation,
+              tilt: datum.tilt
+            );
+          }
+          _pointers.remove(datum.device);
           yield new PointerRemovedEvent(
             timeStamp: timeStamp,
             kind: kind,

packages/flutter/lib/src/painting/edge_insets.dart

@@ -100,7 +100,7 @@ class EdgeInsets {
   Size get collapsedSize => new Size(horizontal, vertical);
 
   /// An EdgeInsets with top and bottom as well as left and right flipped.
-  EdgeInsets get flipped => new EdgeInsets.fromLTRB(left, top, right, bottom);
+  EdgeInsets get flipped => new EdgeInsets.fromLTRB(right, bottom, left, top);
 
   /// Returns a new rect that is bigger than the given rect in each direction by
   /// the amount of inset in each direction. Specifically, the left edge of the

packages/flutter/lib/src/services/platform_messages.dart

@@ -155,9 +155,13 @@ class PlatformMessages {
   /// The given callback will replace the currently registered callback (if any).
   /// To remove the mock handler, pass `null` as the `handler` argument.
   static void setMockStringMessageHandler(String channel, Future<String> handler(String message)) {
-    setMockBinaryMessageHandler(channel, (ByteData message) async {
-      return _encodeUTF8(await handler(_decodeUTF8(message)));
-    });
+    if (handler == null) {
+      setMockBinaryMessageHandler(channel, null);
+    } else {
+      setMockBinaryMessageHandler(channel, (ByteData message) async {
+        return _encodeUTF8(await handler(_decodeUTF8(message)));
+      });
+    }
   }
 
   /// Sets a message handler that intercepts outgoing messages in JSON form.
@@ -165,8 +169,12 @@ class PlatformMessages {
   /// The given callback will replace the currently registered callback (if any).
   /// To remove the mock handler, pass `null` as the `handler` argument.
   static void setMockJSONMessageHandler(String channel, Future<dynamic> handler(dynamic message)) {
-    setMockStringMessageHandler(channel, (String message) async {
-      return _encodeJSON(await handler(_decodeJSON(message)));
-    });
+    if (handler == null) {
+      setMockStringMessageHandler(channel, null);
+    } else {
+      setMockStringMessageHandler(channel, (String message) async {
+        return _encodeJSON(await handler(_decodeJSON(message)));
+      });
+    }
   }
 }

packages/flutter/test/gestures/gesture_binding_test.dart

@@ -132,4 +132,46 @@ void main() {
     expect(events[0].runtimeType, equals(PointerDownEvent));
     expect(events[1].runtimeType, equals(PointerCancelEvent));
   });
+
+  test('Can expand add and hover pointers', () {
+    ui.PointerDataPacket packet = const ui.PointerDataPacket(
+      data: const <ui.PointerData>[
+        const ui.PointerData(change: ui.PointerChange.add, device: 24),
+        const ui.PointerData(change: ui.PointerChange.hover, device: 24),
+        const ui.PointerData(change: ui.PointerChange.remove, device: 24),
+        const ui.PointerData(change: ui.PointerChange.hover, device: 24),
+      ]
+    );
+
+    List<PointerEvent> events = PointerEventConverter.expand(
+      packet.data, ui.window.devicePixelRatio).toList();
+
+    expect(events.length, 5);
+    expect(events[0].runtimeType, equals(PointerAddedEvent));
+    expect(events[1].runtimeType, equals(PointerHoverEvent));
+    expect(events[2].runtimeType, equals(PointerRemovedEvent));
+    expect(events[3].runtimeType, equals(PointerAddedEvent));
+    expect(events[4].runtimeType, equals(PointerHoverEvent));
+  });
+
+  test('Synthetic hover and cancel for misplaced down and remove', () {
+    ui.PointerDataPacket packet = const ui.PointerDataPacket(
+      data: const <ui.PointerData>[
+        const ui.PointerData(change: ui.PointerChange.add, device: 25, physicalX: 10.0, physicalY: 10.0),
+        const ui.PointerData(change: ui.PointerChange.down, device: 25, physicalX: 15.0, physicalY: 17.0),
+        const ui.PointerData(change: ui.PointerChange.remove, device: 25),
+      ]
+    );
+
+    List<PointerEvent> events = PointerEventConverter.expand(
+      packet.data, ui.window.devicePixelRatio).toList();
+
+    expect(events.length, 5);
+    expect(events[0].runtimeType, equals(PointerAddedEvent));
+    expect(events[1].runtimeType, equals(PointerHoverEvent));
+    expect(events[1].delta, equals(const Offset(5.0, 7.0) / ui.window.devicePixelRatio));
+    expect(events[2].runtimeType, equals(PointerDownEvent));
+    expect(events[3].runtimeType, equals(PointerCancelEvent));
+    expect(events[4].runtimeType, equals(PointerRemovedEvent));
+  });
 }

packages/flutter/test/painting/colors_test.dart

+// Copyright 2015 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/painting.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  test('HSVColor control test', () {
+    const HSVColor color = const HSVColor.fromAHSV(0.7, 28.0, 0.3, 0.6);
+
+    expect(color.toString(), hasOneLineDescription);
+    expect(color.hashCode, equals(new HSVColor.fromAHSV(0.7, 28.0, 0.3, 0.6).hashCode));
+
+    expect(color.withAlpha(0.8), const HSVColor.fromAHSV(0.8, 28.0, 0.3, 0.6));
+    expect(color.withHue(123.0), const HSVColor.fromAHSV(0.7, 123.0, 0.3, 0.6));
+    expect(color.withSaturation(0.9), const HSVColor.fromAHSV(0.7, 28.0, 0.9, 0.6));
+    expect(color.withValue(0.1), const HSVColor.fromAHSV(0.7, 28.0, 0.3, 0.1));
+
+    expect(color.toColor(), const Color(0xb399816b));
+
+    HSVColor result = HSVColor.lerp(color, const HSVColor.fromAHSV(0.3, 128.0, 0.7, 0.2), 0.25);
+    expect(result.alpha, 0.6);
+    expect(result.hue, 53.0);
+    expect(result.saturation, greaterThan(0.3999));
+    expect(result.saturation, lessThan(0.4001));
+    expect(result.value, 0.5);
+  });
+}

packages/flutter/test/painting/edge_insets_test.dart

@@ -3,11 +3,39 @@
 // found in the LICENSE file.
 
 import 'package:flutter/painting.dart';
-
-import 'package:test/test.dart';
+import 'package:flutter_test/flutter_test.dart';
 
 void main() {
-  test("EdgeInsets.lerp()", () {
+  test('EdgeInsets control test', () {
+    const EdgeInsets insets = const EdgeInsets.fromLTRB(5.0, 7.0, 11.0, 13.0);
+
+    expect(insets.toString(), hasOneLineDescription);
+    expect(insets.hashCode, equals(new EdgeInsets.fromLTRB(5.0, 7.0, 11.0, 13.0).hashCode));
+
+    expect(insets.topLeft, const Offset(5.0, 7.0));
+    expect(insets.topRight, const Offset(-11.0, 7.0));
+    expect(insets.bottomLeft, const Offset(5.0, -13.0));
+    expect(insets.bottomRight, const Offset(-11.0, -13.0));
+
+    expect(insets.collapsedSize, const Size(16.0, 20.0));
+    expect(insets.flipped, const EdgeInsets.fromLTRB(11.0, 13.0, 5.0, 7.0));
+
+    expect(insets.inflateRect(new Rect.fromLTRB(23.0, 32.0, 124.0, 143.0)),
+           new Rect.fromLTRB(18.0, 25.0, 135.0, 156.0));
+
+    expect(insets.deflateRect(new Rect.fromLTRB(23.0, 32.0, 124.0, 143.0)),
+           new Rect.fromLTRB(28.0, 39.0, 113.0, 130.0));
+
+    expect(insets.inflateSize(const Size(100.0, 125.0)), const Size(116.0, 145.0));
+    expect(insets.deflateSize(const Size(100.0, 125.0)), const Size(84.0, 105.0));
+
+    expect(insets / 2.0, const EdgeInsets.fromLTRB(2.5, 3.5, 5.5, 6.5));
+    expect(insets ~/ 2.0, const EdgeInsets.fromLTRB(2.0, 3.0, 5.0, 6.0));
+    expect(insets % 5.0, const EdgeInsets.fromLTRB(0.0, 2.0, 1.0, 3.0));
+
+  });
+
+  test('EdgeInsets.lerp()', () {
     EdgeInsets a = const EdgeInsets.all(10.0);
     EdgeInsets b = const EdgeInsets.all(20.0);
     expect(EdgeInsets.lerp(a, b, 0.25), equals(a * 1.25));

packages/flutter/test/painting/image_fit_test.dart

@@ -7,7 +7,7 @@ import 'package:flutter/painting.dart';
 import 'package:test/test.dart';
 
 void main() {
-  test("applyImageFit", () {
+  test('applyImageFit', () {
     FittedSizes result;
 
     result = applyImageFit(ImageFit.scaleDown, const Size(100.0, 1000.0), const Size(200.0, 2000.0));
@@ -17,5 +17,13 @@ void main() {
     result = applyImageFit(ImageFit.scaleDown, const Size(300.0, 3000.0), const Size(200.0, 2000.0));
     expect(result.source, equals(const Size(300.0, 3000.0)));
     expect(result.destination, equals(const Size(200.0, 2000.0)));
+
+    result = applyImageFit(ImageFit.fitWidth, const Size(2000.0, 400.0), const Size(1000.0, 100.0));
+    expect(result.source, equals(const Size(2000.0, 200.0)));
+    expect(result.destination, equals(const Size(1000.0, 100.0)));
+
+    result = applyImageFit(ImageFit.fitHeight, const Size(400.0, 2000.0), const Size(100.0, 1000.0));
+    expect(result.source, equals(const Size(200.0, 2000.0)));
+    expect(result.destination, equals(const Size(100.0, 1000.0)));
   });
 }

packages/flutter/test/services/haptic_feedback_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/services.dart';
+import 'package:test/test.dart';
+
+void main() {
+  test('Haptic feedback control test', () async {
+    List<String> log = <String>[];
+
+    PlatformMessages.setMockStringMessageHandler('flutter/platform', (String message) async {
+      log.add(message);
+    });
+
+    await HapticFeedback.vibrate();
+
+    expect(log, equals(<String>['{"method":"HapticFeedback.vibrate","args":[]}']));
+  });
+}

packages/flutter/test/services/image_decoder_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 'dart:ui' as ui;
+import 'dart:typed_data';
+
+import 'package:flutter/services.dart';
+import 'package:test/test.dart';
+
+const List<int> transparentImage = const <int>[
+  0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A, 0x00, 0x00, 0x00, 0x0D, 0x49,
+  0x48, 0x44, 0x52, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01, 0x08, 0x06,
+  0x00, 0x00, 0x00, 0x1F, 0x15, 0xC4, 0x89, 0x00, 0x00, 0x00, 0x0A, 0x49, 0x44,
+  0x41, 0x54, 0x78, 0x9C, 0x63, 0x00, 0x01, 0x00, 0x00, 0x05, 0x00, 0x01, 0x0D,
+  0x0A, 0x2D, 0xB4, 0x00, 0x00, 0x00, 0x00, 0x49, 0x45, 0x4E, 0x44, 0xAE,
+];
+
+void main() {
+  test('Image decoder control test', () async {
+    ui.Image image = await decodeImageFromList(new Uint8List.fromList(transparentImage));
+    expect(image, isNotNull);
+    expect(image.width, 1);
+    expect(image.height, 1);
+  });
+}

packages/flutter/test/services/path_provider_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 'dart:io';
+
+import 'package:flutter/services.dart';
+import 'package:test/test.dart';
+
+void main() {
+  test('Path provider control test', () async {
+    List<String> log = <String>[];
+    String response;
+
+    PlatformMessages.setMockStringMessageHandler('flutter/platform', (String message) async {
+      log.add(message);
+      return response;
+    });
+
+    Directory directory = await PathProvider.getTemporaryDirectory();
+
+    expect(log, equals(<String>['{"method":"PathProvider.getTemporaryDirectory","args":[]}']));
+    expect(directory, isNull);
+    log.clear();
+
+    directory = await PathProvider.getApplicationDocumentsDirectory();
+
+    expect(log, equals(<String>['{"method":"PathProvider.getApplicationDocumentsDirectory","args":[]}']));
+    expect(directory, isNull);
+
+    String fakePath = "/foo/bar/baz";
+    response = '{"path":"$fakePath"}';
+
+    directory = await PathProvider.getTemporaryDirectory();
+    expect(directory.path, equals(fakePath));
+
+    directory = await PathProvider.getApplicationDocumentsDirectory();
+    expect(directory.path, equals(fakePath));
+  });
+}

packages/flutter/test/services/platform_messages_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/services.dart';
+import 'package:test/test.dart';
+
+void main() {
+  test('Mock string message handler control test', () async {
+    List<String> log = <String>[];
+
+    PlatformMessages.setMockStringMessageHandler('test1', (String message) async {
+      log.add(message);
+    });
+
+    await PlatformMessages.sendString('test1', 'hello');
+    expect(log, equals(<String>['hello']));
+    log.clear();
+
+    PlatformMessages.setMockStringMessageHandler('test1', null);
+    await PlatformMessages.sendString('test1', 'fail');
+    expect(log, isEmpty);
+  });
+
+  test('Mock JSON message handler control test', () async {
+    List<dynamic> log = <dynamic>[];
+
+    PlatformMessages.setMockJSONMessageHandler('test2', (dynamic message) async {
+      log.add(message);
+    });
+
+    await PlatformMessages.sendString('test2', '{"hello": "world"}');
+    expect(log, equals(<Map<String, String>>[<String, String>{'hello': 'world'}]));
+    log.clear();
+
+    PlatformMessages.setMockStringMessageHandler('test2', null);
+    await PlatformMessages.sendString('test2', '{"fail": "message"}');
+    expect(log, isEmpty);
+  });
+}

packages/flutter/test/services/system_navigator_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/services.dart';
+import 'package:test/test.dart';
+
+void main() {
+  test('System navigator control test', () async {
+    List<String> log = <String>[];
+
+    PlatformMessages.setMockStringMessageHandler('flutter/platform', (String message) async {
+      log.add(message);
+    });
+
+    await SystemNavigator.pop();
+
+    expect(log, equals(<String>['{"method":"SystemNavigator.pop","args":[]}']));
+  });
+}

packages/flutter/test/services/system_sound_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/services.dart';
+import 'package:test/test.dart';
+
+void main() {
+  test('System sound control test', () async {
+    List<String> log = <String>[];
+
+    PlatformMessages.setMockStringMessageHandler('flutter/platform', (String message) async {
+      log.add(message);
+    });
+
+    await SystemSound.play(SystemSoundType.click);
+
+    expect(log, equals(<String>['{"method":"SystemSound.play","args":["SystemSoundType.click"]}']));
+  });
+}

packages/flutter/test/services/url_launcher_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/services.dart';
+import 'package:test/test.dart';
+
+void main() {
+  test('URL launcher control test', () async {
+    List<String> log = <String>[];
+
+    PlatformMessages.setMockStringMessageHandler('flutter/platform', (String message) async {
+      log.add(message);
+    });
+
+    await UrlLauncher.launch('http://example.com/');
+
+    expect(log, equals(<String>['{"method":"UrlLauncher.launch","args":["http://example.com/"]}']));
+  });
+}