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.Generic;
31 using System.Reflection;
33 namespace NUnit.Framework.Constraints
36 /// Predicate constraint wraps a Predicate in a constraint,
37 /// returning success if the predicate is true.
39 public class PredicateConstraint<T> : Constraint
41 readonly Predicate<T> predicate;
44 /// Construct a PredicateConstraint from a predicate
46 public PredicateConstraint(Predicate<T> predicate)
48 this.predicate = predicate;
52 /// Gets text describing a constraint
54 public override string Description
59 var name = predicate.GetMethodInfo().Name;
61 var name = predicate.Method.Name;
63 return name.StartsWith("<")
64 ? "value matching lambda expression"
65 : "value matching " + name;
70 /// Determines whether the predicate succeeds when applied
71 /// to the actual value.
73 public override ConstraintResult ApplyTo<TActual>(TActual actual)
76 throw new ArgumentException("The actual value is not of type " + typeof(T).Name, "actual");
78 return new ConstraintResult(this, actual, predicate((T)(object)actual));