1 // ***********************************************************************
2 // Copyright (c) 2009 Charlie Poole
4 // Permission is hereby granted, free of charge, to any person obtaining
5 // a copy of this software and associated documentation files (the
6 // "Software"), to deal in the Software without restriction, including
7 // without limitation the rights to use, copy, modify, merge, publish,
8 // distribute, sublicense, and/or sell copies of the Software, and to
9 // permit persons to whom the Software is furnished to do so, subject to
10 // the following conditions:
12 // The above copyright notice and this permission notice shall be
13 // included in all copies or substantial portions of the Software.
15 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
19 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
20 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
21 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22 // ***********************************************************************
25 #define NUNIT_FRAMEWORK
30 using System.Collections;
31 using System.Reflection;
32 using NUnit.Compatibility;
34 namespace NUnit.Framework.Constraints
37 /// NUnitComparer encapsulates NUnit's default behavior
38 /// in comparing two objects.
40 public class NUnitComparer : IComparer
43 /// Returns the default NUnitComparer.
45 public static NUnitComparer Default
47 get { return new NUnitComparer(); }
51 /// Compares two objects
53 /// <param name="x"></param>
54 /// <param name="y"></param>
55 /// <returns></returns>
56 public int Compare(object x, object y)
59 return y == null ? 0 : -1;
63 if (x is char && y is char)
64 return (char)x == (char)y ? 0 : 1;
66 if (Numerics.IsNumericType(x) && Numerics.IsNumericType(y))
67 return Numerics.Compare(x, y);
70 return ((IComparable)x).CompareTo(y);
73 return -((IComparable)y).CompareTo(x);
75 Type xType = x.GetType();
76 Type yType = y.GetType();
78 MethodInfo method = xType.GetMethod("CompareTo", new Type[] { yType });
80 return (int)method.Invoke(x, new object[] { y });
82 method = yType.GetMethod("CompareTo", new Type[] { xType });
84 return -(int)method.Invoke(y, new object[] { x });
86 throw new ArgumentException("Neither value implements IComparable or IComparable<T>");