mcs/class/System.Core/Test/System.Linq/QueryableTest.cs

   1 //
   2 // Queryable.cs
   3 //
   4 // Author:
   5 //   Jb Evain (jbevain@novell.com)
   6 //
   7 // (C) 2007 Novell, Inc. (http://www.novell.com)
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28
  29 using System;
  30 using System.Collections;
  31 using System.Collections.Generic;
  32 using System.Linq;
  33 using System.Linq.Expressions;
  34 using System.Reflection;
  35
  36 using NUnit.Framework;
  37
  38 namespace MonoTests.System.Linq {
  39
  40         [TestFixture]
  41         public class QueryableTest {
  42
  43                 [Test]
  44                 public void TestElementType ()
  45                 {
  46                         var data = new int [] { 1, 2, 3 };
  47                         var queryable = data.AsQueryable ();
  48
  49                         Assert.AreEqual (typeof (int), queryable.ElementType);
  50                 }
  51
  52                 [Test]
  53                 public void TestCount ()
  54                 {
  55                         var q = CreateQueryable<string> ();
  56
  57                         q.Count ();
  58
  59                         AssertReceived (GetMethod ("Count", 0), q);
  60                 }
  61
  62                 [Test]
  63                 public void TestCountPredicate ()
  64                 {
  65                         var q = CreateQueryable<string> ();
  66
  67                         q.Count (s => true);
  68
  69                         AssertReceived (GetMethod ("Count", 1), q);
  70                 }
  71
  72                 public static void AssertReceived<T> (MethodInfo method, MockQuery<T> query)
  73                 {
  74                         Expression expression = query.MockProvider.Received;
  75
  76                         MethodCallExpression call = expression as MethodCallExpression;
  77
  78                         Assert.IsNotNull (call, "Expected a MethodCallExpression");
  79
  80                         MethodInfo expected = method.MakeGenericMethod (typeof (T));
  81
  82                         Assert.AreEqual (expected, call.Method, "Expected method: " + expected);
  83                 }
  84
  85                 public static MethodInfo GetMethod (string name, int parameters)
  86                 {
  87                         var methods = from m in typeof (Queryable).GetMethods ()
  88                                                   where m.Name == name && m.GetParameters ().Length == parameters + 1
  89                                                   select m;
  90
  91                         return methods.First ();
  92                 }
  93
  94                 static MockQuery<T> CreateQueryable<T> ()
  95                 {
  96                         return new MockQuery<T> (new MockQueryProvider ());
  97                 }
  98
  99                 public class MockQueryProvider : IQueryProvider {
 100
 101                         Expression received;
 102
 103                         public Expression Received {
 104                                 get { return received; }
 105                         }
 106
 107                         public IQueryable<TElement> CreateQuery<TElement> (Expression expression)
 108                         {
 109                                 throw new NotImplementedException ();
 110                         }
 111
 112                         public IQueryable CreateQuery (Expression expression)
 113                         {
 114                                 throw new NotImplementedException ();
 115                         }
 116
 117                         public TResult Execute<TResult> (Expression expression)
 118                         {
 119                                 received = expression;
 120
 121                                 return default (TResult);
 122                         }
 123
 124                         public object Execute (Expression expression)
 125                         {
 126                                 throw new NotImplementedException ();
 127                         }
 128                 }
 129
 130                 public class MockQuery<T> : IQueryable<T> {
 131
 132                         MockQueryProvider provider;
 133                         Expression expression;
 134
 135                         public Type ElementType {
 136                                 get { return typeof (T); }
 137                         }
 138
 139                         public Expression Expression {
 140                                 get { return expression; }
 141                         }
 142
 143                         public IQueryProvider Provider {
 144                                 get { return provider; }
 145                         }
 146
 147                         public MockQueryProvider MockProvider {
 148                                 get { return provider; }
 149                         }
 150
 151                         public MockQuery (MockQueryProvider provider)
 152                         {
 153                                 this.provider = provider;
 154                                 this.expression = Expression.Constant (this);
 155                         }
 156
 157                         public MockQuery (MockQueryProvider provider, Expression expression)
 158                         {
 159                                 this.provider = provider;
 160                                 this.expression = expression;
 161                         }
 162
 163                         public IEnumerator<T> GetEnumerator ()
 164                         {
 165                                 throw new NotImplementedException ();
 166                         }
 167
 168                         IEnumerator IEnumerable.GetEnumerator ()
 169                         {
 170                                 return GetEnumerator ();
 171                         }
 172                 }
 173
 174         }
 175 }