implemented CSharp475 and added tests.

Author: craiggwilson

Driver/Linq/Translators/SelectQuery.cs

@@ -173,8 +173,10 @@ public override object Execute()
                 }
                 else
                 {
-                    // TODO: handle projection after OfType
-                    throw new NotSupportedException();
+                    var paramExpression = Expression.Parameter(DocumentType, "x");
+                    var convertExpression = Expression.Convert(paramExpression, _ofType);
+                    var body = ExpressionParameterReplacer.ReplaceParameter(projection.Body, projection.Parameters[0], convertExpression);
+                    projection = Expression.Lambda(body, paramExpression);
                 }
             }
 

DriverUnitTests/DriverUnitTests.csproj

@@ -126,6 +126,7 @@
     <Compile Include="GridFS\MongoGridFSSettingsTests.cs" />
     <Compile Include="GridFS\MongoGridFSStreamTests.cs" />
     <Compile Include="GridFS\MongoGridFSTests.cs" />
+    <Compile Include="Jira\CSharp475Tests.cs" />
     <Compile Include="Jira\CSharp101Tests.cs" />
     <Compile Include="Jira\CSharp103Tests.cs" />
     <Compile Include="Jira\CSharp110Tests.cs" />

DriverUnitTests/Jira/CSharp475Tests.cs

@@ -0,0 +1,65 @@
+/* Copyright 2010-2012 10gen Inc.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+* http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Runtime.Serialization;
+using System.Text;
+using NUnit.Framework;
+
+using MongoDB.Bson;
+using MongoDB.Bson.Serialization.Attributes;
+using MongoDB.Driver;
+using MongoDB.Driver.Builders;
+using MongoDB.Driver.Linq;
+
+namespace MongoDB.DriverUnitTests.Jira.CSharp475
+{
+    [TestFixture]
+    public class CSharp475Tests
+    {
+        public abstract class Base
+        {
+            public ObjectId Id { get; set; }
+
+            public string A { get; set; }
+        }
+
+        public class T1 : Base
+        {
+            public string B { get; set; }
+        }
+
+        [Test]
+        public void ProjectAfterOfTypeTest()
+        {
+            var server = MongoServer.Create();
+            var db = server.GetDatabase("csharp475");
+            var collection = db.GetCollection<Base>("ProjectTest");
+            collection.Drop();
+            
+
+            var t1 = new T1 { A = "T1.A", B = "T1.B" };
+            collection.Insert(t1);
+
+            var query = from t in collection.AsQueryable().OfType<T1>() select t.B;
+            var results = query.ToList();
+            Assert.That(results.Count, Is.EqualTo(1));
+            Assert.That(results[0], Is.EqualTo("T1.B"));
+        }
+    }
+}

DriverUnitTests/Linq/SelectOfTypeTests.cs

@@ -151,6 +151,29 @@ public void TestOfTypeD()
             Assert.AreEqual(1, Consume(query));
         }
 
+        [Test]
+        public void TestOfTypeDWithProjection()
+        {
+            var query = _collection.AsQueryable<B>().OfType<D>().Select(x => new { A = x.d });
+
+            var translatedQuery = MongoQueryTranslator.Translate(query);
+            Assert.IsInstanceOf<SelectQuery>(translatedQuery);
+            Assert.AreSame(_collection, translatedQuery.Collection);
+            Assert.AreSame(typeof(B), translatedQuery.DocumentType);
+
+            var selectQuery = (SelectQuery)translatedQuery;
+            Assert.AreEqual("(B x) => LinqToMongo.Inject({ \"_t\" : \"D\" })", ExpressionFormatter.ToString(selectQuery.Where));
+            Assert.AreEqual(typeof(D), selectQuery.OfType);
+            Assert.IsNull(selectQuery.OrderBy);
+            Assert.IsNotNull(selectQuery.Projection);
+            Assert.AreEqual("(D x) => new <>f__AnonymousType1`1(x.d)", ExpressionFormatter.ToString(selectQuery.Projection));
+            Assert.IsNull(selectQuery.Skip);
+            Assert.IsNull(selectQuery.Take);
+
+            Assert.AreEqual("{ \"_t\" : \"D\" }", selectQuery.BuildQuery().ToJson());
+            Assert.AreEqual(1, Consume(query));
+        }
+
         [Test]
         public void TestWhereBGreaterThan0OfTypeCWhereCGreaterThan0()
         {