Improve test coverage in rendering.dart (#4775)

packages/flutter/lib/rendering.dart

@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 /// The Flutter rendering tree.
-/// 
+///
 /// To use, import `package:flutter/rendering.dart`.
 ///
 /// The [RenderObject] hierarchy is used by the Flutter Widgets
@@ -48,6 +48,7 @@ export 'src/rendering/semantics.dart';
 export 'src/rendering/shifted_box.dart';
 export 'src/rendering/stack.dart';
 export 'src/rendering/table.dart';
+export 'src/rendering/tweens.dart';
 export 'src/rendering/view.dart';
 export 'src/rendering/viewport.dart';
 

packages/flutter/lib/src/rendering/block.dart

@@ -51,13 +51,13 @@ class RenderBlock extends RenderBox
   }
 
   BoxConstraints _getInnerConstraints(BoxConstraints constraints) {
+    assert(_mainAxis != null);
     switch (_mainAxis) {
       case Axis.horizontal:
         return new BoxConstraints.tightFor(height: constraints.maxHeight);
       case Axis.vertical:
         return new BoxConstraints.tightFor(width: constraints.maxWidth);
     }
-    assert(_mainAxis != null);
     return null;
   }
 
@@ -66,13 +66,13 @@ class RenderBlock extends RenderBox
     if (child == null)
       return 0.0;
     BoxParentData parentData = child.parentData;
+    assert(mainAxis != null);
     switch (mainAxis) {
       case Axis.horizontal:
         return parentData.offset.dx + child.size.width;
       case Axis.vertical:
         return parentData.offset.dy + child.size.height;
     }
-    assert(mainAxis != null);
     return null;
   }
 
@@ -183,49 +183,49 @@ class RenderBlock extends RenderBox
 
   @override
   double computeMinIntrinsicWidth(double height) {
+    assert(mainAxis != null);
     switch (mainAxis) {
       case Axis.horizontal:
         return _getIntrinsicMainAxis((RenderBox child) => child.getMinIntrinsicWidth(height));
       case Axis.vertical:
         return _getIntrinsicCrossAxis((RenderBox child) => child.getMinIntrinsicWidth(height));
     }
-    assert(mainAxis != null);
     return null;
   }
 
   @override
   double computeMaxIntrinsicWidth(double height) {
+    assert(mainAxis != null);
     switch (mainAxis) {
       case Axis.horizontal:
         return _getIntrinsicMainAxis((RenderBox child) => child.getMaxIntrinsicWidth(height));
       case Axis.vertical:
         return _getIntrinsicCrossAxis((RenderBox child) => child.getMaxIntrinsicWidth(height));
     }
-    assert(mainAxis != null);
     return null;
   }
 
   @override
   double computeMinIntrinsicHeight(double width) {
+    assert(mainAxis != null);
     switch (mainAxis) {
       case Axis.horizontal:
         return _getIntrinsicMainAxis((RenderBox child) => child.getMinIntrinsicHeight(width));
       case Axis.vertical:
         return _getIntrinsicCrossAxis((RenderBox child) => child.getMinIntrinsicHeight(width));
     }
-    assert(mainAxis != null);
     return null;
   }
 
   @override
   double computeMaxIntrinsicHeight(double width) {
+    assert(mainAxis != null);
     switch (mainAxis) {
       case Axis.horizontal:
         return _getIntrinsicMainAxis((RenderBox child) => child.getMaxIntrinsicHeight(width));
       case Axis.vertical:
         return _getIntrinsicCrossAxis((RenderBox child) => child.getMaxIntrinsicHeight(width));
     }
-    assert(mainAxis != null);
     return null;
   }
 

packages/flutter/lib/src/rendering/box.dart

@@ -5,7 +5,6 @@
 import 'dart:math' as math;
 import 'dart:ui' as ui show lerpDouble;
 
-import 'package:flutter/animation.dart';
 import 'package:flutter/gestures.dart';
 import 'package:meta/meta.dart';
 import 'package:vector_math/vector_math_64.dart';
@@ -1456,17 +1455,3 @@ abstract class RenderBoxContainerDefaultsMixin<ChildType extends RenderBox, Pare
     return result;
   }
 }
-
-/// An interpolation between two fractional offsets.
-///
-/// This class specializes the interpolation of Tween<FractionalOffset> to be
-/// appropriate for rectangles.
-class FractionalOffsetTween extends Tween<FractionalOffset> {
-  /// Creates a fractional offset tween.
-  ///
-  /// The [begin] and [end] arguments must not be null.
-  FractionalOffsetTween({ FractionalOffset begin, FractionalOffset end }) : super(begin: begin, end: end);
-
-  @override
-  FractionalOffset lerp(double t) => FractionalOffset.lerp(begin, end, t);
-}

packages/flutter/lib/src/rendering/tweens.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/animation.dart';
+import 'package:flutter/painting.dart';
+
+/// An interpolation between two fractional offsets.
+///
+/// This class specializes the interpolation of Tween<FractionalOffset> to be
+/// appropriate for rectangles.
+class FractionalOffsetTween extends Tween<FractionalOffset> {
+  /// Creates a fractional offset tween.
+  ///
+  /// The [begin] and [end] arguments must not be null.
+  FractionalOffsetTween({ FractionalOffset begin, FractionalOffset end })
+    : super(begin: begin, end: end);
+
+  @override
+  FractionalOffset lerp(double t) => FractionalOffset.lerp(begin, end, t);
+}

packages/flutter/test/rendering/box_constraints_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/rendering.dart';
+import 'package:test/test.dart';
+
+void main() {
+  test('BoxConstraints toString', () {
+    expect(const BoxConstraints.expand().toString(), contains('biggest'));
+    expect(new BoxConstraints().toString(), contains('unconstrained'));
+    expect(new BoxConstraints.tightFor(width: 50.0).toString(), contains('w=50'));
+  });
+
+  test('BoxConstraints copyWith', () {
+    BoxConstraints constraints = new BoxConstraints(
+      minWidth: 3.0,
+      maxWidth: 7.0,
+      minHeight: 11.0,
+      maxHeight: 17.0
+    );
+    BoxConstraints copy = constraints.copyWith();
+    expect(copy, equals(constraints));
+    copy = constraints.copyWith(
+      minWidth: 13.0,
+      maxWidth: 17.0,
+      minHeight: 111.0,
+      maxHeight: 117.0
+    );
+    expect(copy.minWidth, 13.0);
+    expect(copy.maxWidth, 17.0);
+    expect(copy.minHeight, 111.0);
+    expect(copy.maxHeight, 117.0);
+    expect(copy, isNot(equals(constraints)));
+    expect(copy.hashCode, isNot(equals(constraints.hashCode)));
+  });
+
+  test('BoxConstraints operators', () {
+    BoxConstraints constraints = new BoxConstraints(
+      minWidth: 3.0,
+      maxWidth: 7.0,
+      minHeight: 11.0,
+      maxHeight: 17.0
+    );
+    BoxConstraints copy = constraints * 2.0;
+    expect(copy.minWidth, 6.0);
+    expect(copy.maxWidth, 14.0);
+    expect(copy.minHeight, 22.0);
+    expect(copy.maxHeight, 34.0);
+    expect(copy / 2.0, equals(constraints));
+    copy = constraints ~/ 2.0;
+    expect(copy.minWidth, 1.0);
+    expect(copy.maxWidth, 3.0);
+    expect(copy.minHeight, 5.0);
+    expect(copy.maxHeight, 8.0);
+    copy = constraints % 3.0;
+    expect(copy.minWidth, 0.0);
+    expect(copy.maxWidth, 1.0);
+    expect(copy.minHeight, 2.0);
+    expect(copy.maxHeight, 2.0);
+  });
+
+  test('BoxConstraints lerp', () {
+    expect(BoxConstraints.lerp(null, null, 0.5), isNull);
+    BoxConstraints constraints = new BoxConstraints(
+      minWidth: 3.0,
+      maxWidth: 7.0,
+      minHeight: 11.0,
+      maxHeight: 17.0
+    );
+    BoxConstraints copy = BoxConstraints.lerp(null, constraints, 0.5);
+    expect(copy.minWidth, 1.5);
+    expect(copy.maxWidth, 3.5);
+    expect(copy.minHeight, 5.5);
+    expect(copy.maxHeight, 8.5);
+    copy = BoxConstraints.lerp(constraints, null, 0.5);
+    expect(copy.minWidth, 1.5);
+    expect(copy.maxWidth, 3.5);
+    expect(copy.minHeight, 5.5);
+    expect(copy.maxHeight, 8.5);
+    copy = BoxConstraints.lerp(new BoxConstraints(
+      minWidth: 13.0,
+      maxWidth: 17.0,
+      minHeight: 111.0,
+      maxHeight: 117.0
+    ), constraints, 0.2);
+    expect(copy.minWidth, 11.0);
+    expect(copy.maxWidth, 15.0);
+    expect(copy.minHeight, 91.0);
+    expect(copy.maxHeight, 97.0);
+  });
+
+  test('BoxConstraints normalize', () {
+    BoxConstraints constraints = new BoxConstraints(
+      minWidth: 3.0,
+      maxWidth: 2.0,
+      minHeight: 11.0,
+      maxHeight: 18.0
+    );
+    BoxConstraints copy = constraints.normalize();
+    expect(copy.minWidth, 3.0);
+    expect(copy.maxWidth, 3.0);
+    expect(copy.minHeight, 11.0);
+    expect(copy.maxHeight, 18.0);
+  });
+}