// 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. /// Test of a common rounding bug. /// /// This bug is common in JavaScript implementations because the ECMA-262 /// specification of JavaScript incorrectly claims: /// /// The value of [:Math.round(x):] is the same as the value of /// [:Math.floor(x+0.5):], except when x is 0 or is less than 0 but greater /// than or equal to -0.5; for these cases [:Math.round(x):] returns 0, but /// [:Math.floor(x+0.5):] returns +0. /// /// However, 0.49999999999999994 + 0.5 is 1 and 9007199254740991 + 0.5 is /// 9007199254740992, so you cannot implement Math.round in terms of /// Math.floor. import 'package:expect/expect.dart'; main() { Expect.equals(0, (0.49999999999999994).round()); Expect.equals(0, (-0.49999999999999994).round()); Expect.equals(9007199254740991, (9007199254740991.0).round()); Expect.equals(-9007199254740991, (-9007199254740991.0).round()); }