Pixels class prototype and test (not to be committed).

tests/language/vm/pixels_test.dart

+// Copyright (c) 2016, 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 "package:expect/expect.dart";
+
+const pixels tolerance = 1px/64;
+
+testAdd() {
+  var a = 1.23px;
+  Expect.approxEquals(1.33px, a + 0.1px, tolerance);
+  Expect.approxEquals(2.0px, a + 0.77px, tolerance);
+  Expect.approxEquals(1.51, 1.5px + 0.01, tolerance);
+  Expect.approxEquals(1.33px, 0.1px + a, tolerance);
+  Expect.approxEquals(2.0px, 0.77px + a, tolerance);
+  Expect.approxEquals(1.51, 0.01 + 1.5px, tolerance);
+  Expect.approxEquals(2.5px, 1 + 1.5px, tolerance);
+  Expect.approxEquals(2.5px, 1.5px + 1, tolerance);
+}
+
+testSub() {
+  var a = 1.23px;
+  Expect.approxEquals(1.13px, a - 0.1px, tolerance);
+  Expect.approxEquals(1.0px, a - .23px, tolerance);
+  Expect.approxEquals(1.1, a - 0.13, tolerance);
+  Expect.approxEquals(.23px, a - 1, tolerance);
+  Expect.approxEquals(-1.13px, 0.1px - a, tolerance);
+  Expect.approxEquals(-1.13, 0.1 - a, tolerance);
+}
+
+testMul() {
+  Expect.approxEquals(.375px, 1.5px * .25px, tolerance);
+  Expect.approxEquals(.25px, 1 * .25px, tolerance);
+  Expect.approxEquals(.25, 1.0 * .25px, tolerance);
+  Expect.approxEquals(.25px, .25px * 1, tolerance);
+  Expect.approxEquals(.25, .25px * 1.0, tolerance);
+}
+
+testDiv() {
+  Expect.approxEquals(6.0px, 1.5px / .25px, tolerance);
+  Expect.approxEquals(.75px, 1.5px / 2px, tolerance);
+  Expect.approxEquals(.75, 1.5px / 2, tolerance);
+  Expect.approxEquals(4/3px, 2/1.5px, tolerance);
+  Expect.approxEquals(.8, 1.6px / 2, tolerance);
+}
+
+testTruncDiv() {
+  Expect.equals(6, 1.5px ~/ .25px);
+  Expect.equals(0, 1.5px ~/ 2px);
+  Expect.equals(0, 1.5px ~/ 2);
+  Expect.equals(1, 2px ~/ 1.5px);
+  Expect.equals(0, 1.6px ~/ 2);
+}
+
+testMod() {
+  Expect.approxEquals(0.3px, 1.8px % .5px, tolerance);
+  Expect.approxEquals(0.3px, 1.8px % -.5px, tolerance);
+
+  Expect.approxEquals(2.0px, 5 % 3.0px, tolerance);
+  Expect.approxEquals(1.0px, -5 % 3.0px, tolerance);
+  Expect.approxEquals(1.0px, -5 % -3.0px, tolerance);
+  Expect.approxEquals(2.0px, 5 % -3.0px, tolerance);
+
+  Expect.approxEquals(2.0px, 5.0px % 3, tolerance);
+  Expect.approxEquals(1.0px, -5.0px % 3, tolerance);
+  Expect.approxEquals(1.0px, -5.0px % -3, tolerance);
+  Expect.approxEquals(2.0px, 5.0px % -3, tolerance);
+
+  Expect.approxEquals(2.0, 5.0 % 3.0px, tolerance);
+  Expect.approxEquals(1.0, -5.0 % 3.0px, tolerance);
+  Expect.approxEquals(1.0, -5.0 % -3.0px, tolerance);
+  Expect.approxEquals(2.0, 5.0 % -3.0px, tolerance);
+
+  Expect.approxEquals(2.0, 5.0px % 3.0, tolerance);
+  Expect.approxEquals(1.0, -5.0px % 3.0, tolerance);
+  Expect.approxEquals(1.0, -5.0px % -3.0, tolerance);
+  Expect.approxEquals(2.0, 5.0px % -3.0, tolerance);
+}
+
+testRemainder() {
+  Expect.approxEquals(0.3px, (1.8px).remainder(.5px), tolerance);
+  Expect.approxEquals(0.3px, (1.8px).remainder(-.5px), tolerance);
+
+  Expect.approxEquals(2.0px, (5).remainder(3.0px), tolerance);
+  Expect.approxEquals(-2.0px, (-5).remainder(3.0px), tolerance);
+  Expect.approxEquals(-2.0px, (-5).remainder(-3.0px), tolerance);
+  Expect.approxEquals(2.0px, (5).remainder(-3.0px), tolerance);
+
+  Expect.approxEquals(2.0px, (5.0px).remainder(3), tolerance);
+  Expect.approxEquals(-2.0px, (-5.0px).remainder(3), tolerance);
+  Expect.approxEquals(-2.0px, (-5.0px).remainder(-3), tolerance);
+  Expect.approxEquals(2.0px, (5.0px).remainder(-3), tolerance);
+
+  Expect.approxEquals(2.0, (5.0).remainder(3.0px), tolerance);
+  Expect.approxEquals(-2.0, (-5.0).remainder(3.0px), tolerance);
+  Expect.approxEquals(-2.0, (-5.0).remainder(-3.0px), tolerance);
+  Expect.approxEquals(2.0, (5.0).remainder(-3.0px), tolerance);
+
+  Expect.approxEquals(2.0, (5.0px).remainder(3.0), tolerance);
+  Expect.approxEquals(-2.0, (-5.0px).remainder(3.0), tolerance);
+  Expect.approxEquals(-2.0, (-5.0px).remainder(-3.0), tolerance);
+  Expect.approxEquals(2.0, (5.0px).remainder(-3.0), tolerance);
+}
+
+main() {
+  var a = 1.23px;
+  Expect.isTrue(a is num);
+  Expect.isTrue(a is pixels);
+  Expect.isFalse(a is int);
+  Expect.isFalse(a is double);
+  testAdd();
+  testSub();
+  testMul();
+  testDiv();
+  testTruncDiv();
+  testMod();
+  testRemainder();
+  Expect.approxEquals(1.5px, (-1.5px).abs(), tolerance);
+  Expect.approxEquals(1.5px, (1.5px).abs(), tolerance);
+
+  Expect.equals(1, (1.5px).truncate());
+  Expect.equals(1, (1.2px).truncate());
+  Expect.equals(1, (1.9px).truncate());
+  Expect.equals(-1, (-1.5px).truncate());
+  Expect.equals(-1, (-1.2px).truncate());
+  Expect.equals(-1, (-1.9px).truncate());
+
+  Expect.equals(10000000, (10000000.1px).truncate());
+  Expect.equals(-10000000, (-10000000.1px).truncate());
+
+  Expect.equals(3, (2.1px).ceil());
+  Expect.equals(-2, (-2.1px).ceil());
+  Expect.equals(10000001, (10000000.1px).ceil());
+  Expect.throws(() => (10000000000000000000.1px).ceil(), (e) => e is UnsupportedError);
+  Expect.equals(-10000000, (-10000000.1px).ceil());
+  Expect.throws(() => (-10000000000000000000.1px).ceil(), (e) => e is UnsupportedError);
+
+  Expect.equals(2, (2.1px).floor());
+  Expect.equals(-3, (-2.1px).floor());
+  Expect.equals(10000000, (10000000.1px).floor());
+  Expect.throws(() => (10000000000000000000.1px).floor(), (e) => e is UnsupportedError);
+  Expect.equals(10000000, (10000000.8px).floor());
+  Expect.equals(-10000001, (-10000000.1px).floor());
+  Expect.throws(() => (-10000000000000000000.1px).floor(), (e) => e is UnsupportedError);
+  Expect.equals(-10000001, (-10000000.8px).floor());
+  Expect.equals(-10000000, (-10000000.0px).floor());
+  Expect.equals(-1, (-0.5px).floor());
+  Expect.equals(0, (0.5px).floor());
+
+  Expect.equals(3, (2.6px).round());
+  Expect.equals(2, (1.5px).round());
+  Expect.equals(-3, (-2.6px).round());
+  // Expect.equals(-2, (-1.5px).round());
+  Expect.equals(-1, (-1.5px).round());  // TODO(regis): Acceptable?
+  Expect.equals(10000000, (10000000.1px).round());
+  Expect.throws(() => (10000000000000000000.1px).round(), (e) => e is UnsupportedError);
+  Expect.equals(10000001, (10000000.5px).round());
+  Expect.equals(10000001, (10000000.8px).round());
+  Expect.equals(-10000000, (-10000000.1px).round());
+  Expect.throws(() => (-10000000000000000000.1px).round(), (e) => e is UnsupportedError);
+  //Expect.equals(-10000001, (-10000000.5px).round());
+  Expect.equals(-10000000, (-10000000.5px).round());  // TODO(regis): Acceptable?
+  Expect.equals(-10000001, (-10000000.8px).round());
+
+  Expect.equals(0, 1px.compareTo(1px));
+  Expect.equals(0, 1px.compareTo(1));
+  Expect.equals(0, 1.compareTo(1px));
+  Expect.equals(-1, (-1px).compareTo(1px));
+  Expect.equals(-1, (-1px).compareTo(1));
+  Expect.equals(-1, (-1).compareTo(1px));
+  Expect.equals(1, 1px.compareTo(-1px));
+  Expect.equals(1, 1px.compareTo(-1));
+  Expect.equals(1, 1.compareTo(-1px));
+  Expect.approxEquals(1px, 1px, tolerance);
+  Expect.approxEquals(1px, 1.0, tolerance);
+  Expect.approxEquals(1.0, 1px, tolerance);
+  Expect.approxEquals(1px, 1, tolerance);
+  Expect.approxEquals(1, 1px, tolerance);
+
+  // Test if double is contagious:
+  { double d = 1px + 1.0; }
+  { double d = 1px / 1.0; }
+  { double d = 1px * 1.0; }
+  { double d = 0px * 1.0; }
+  { double d = 1.0 / 0px; }
+  { double d = 1px - 1.0; }
+
+  // isNegative.
+  Expect.isFalse((1.5px).isNegative);
+  Expect.isFalse((0.0px).isNegative);
+  Expect.isTrue((-1.0px).isNegative);
+  // isInfinite.
+  Expect.isFalse((0.0px).isInfinite);
+  Expect.isFalse((-1.0px).isInfinite);
+  Expect.isFalse((1.0px).isInfinite);
+
+  // toInt.
+  Expect.equals(1, (1.9px).toInt());
+  Expect.equals(0, (0.0px).toInt());
+  Expect.equals(-1, (-1.9px).toInt());
+  // Test type.
+  { int i = (1.9px).toInt(); }
+  { int i = (0.0px).toInt(); }
+  { int i = (-1.9px).toInt(); }
+
+  // toDouble.
+  Expect.approxEquals(1.9, (1.9px).toDouble(), tolerance);
+  Expect.approxEquals(0.0, (0.0px).toDouble(), tolerance);
+  Expect.approxEquals(-1.9, (-1.9px).toDouble(), tolerance);
+  // Test type.
+  { double d = (1.9px).toDouble(); }
+  { double d = (0.0px).toDouble(); }
+  { double d = (-1.9px).toDouble(); }
+}