implemented CSHARP_462 to support local collection Contains operations translating into In queries.

Author: craiggwilson

Driver/Linq/Translators/SelectQuery.cs

@@ -521,6 +521,11 @@ private IMongoQuery BuildContainsQuery(MethodCallExpression methodCallExpression
                 return BuildStringQuery(methodCallExpression);
             }
 
+            if (methodCallExpression.Object != null && methodCallExpression.Object.NodeType == ExpressionType.Constant)
+            {
+                return BuildInQuery(methodCallExpression);
+            }
+
             BsonSerializationInfo serializationInfo = null;
             ConstantExpression valueExpression = null;
             var arguments = methodCallExpression.Arguments.ToArray();
@@ -536,6 +541,10 @@ private IMongoQuery BuildContainsQuery(MethodCallExpression methodCallExpression
             {
                 if (methodCallExpression.Method.DeclaringType == typeof(Enumerable))
                 {
+                    if (arguments[0].NodeType == ExpressionType.Constant)
+                    {
+                        return BuildInQuery(methodCallExpression);
+                    }
                     serializationInfo = GetSerializationInfo(arguments[0]);
                     valueExpression = arguments[1] as ConstantExpression;
                 }
@@ -610,20 +619,46 @@ private IMongoQuery BuildEqualsQuery(MethodCallExpression methodCallExpression)
 
         private IMongoQuery BuildInQuery(MethodCallExpression methodCallExpression)
         {
-            if (methodCallExpression.Method.DeclaringType == typeof(LinqToMongo))
+            var methodDeclaringType = methodCallExpression.Method.DeclaringType;
+            var arguments = methodCallExpression.Arguments.ToArray();
+            BsonSerializationInfo serializationInfo = null;
+            ConstantExpression valuesExpression = null;
+            if (methodDeclaringType == typeof(LinqToMongo))
             {
-                var arguments = methodCallExpression.Arguments.ToArray();
                 if (arguments.Length == 2)
                 {
-                    var serializationInfo = GetSerializationInfo(arguments[0]);
-                    var valuesExpression = arguments[1] as ConstantExpression;
-                    if (serializationInfo != null && valuesExpression != null)
-                    {
-                        var serializedValues = SerializeValues(serializationInfo, (IEnumerable)valuesExpression.Value);
-                        return Query.In(serializationInfo.ElementName, serializedValues);
-                    }
+                    serializationInfo = GetSerializationInfo(arguments[0]);
+                    valuesExpression = arguments[1] as ConstantExpression;
                 }
             }
+            else if (methodDeclaringType == typeof(Enumerable) || methodDeclaringType == typeof(Queryable))
+            {
+                if (arguments.Length == 2)
+                {
+                    serializationInfo = GetSerializationInfo(arguments[1]);
+                    valuesExpression = arguments[0] as ConstantExpression;
+                }
+            }
+            else
+            {
+                if (methodDeclaringType.IsGenericType)
+                {
+                    methodDeclaringType = methodDeclaringType.GetGenericTypeDefinition();
+                }
+
+                bool contains = methodDeclaringType.GetInterface("ICollection`1") != null;
+                if (contains && arguments.Length == 1)
+                {
+                    serializationInfo = GetSerializationInfo(arguments[0]);
+                    valuesExpression = methodCallExpression.Object as ConstantExpression;
+                }
+            }
+
+            if (serializationInfo != null && valuesExpression != null)
+            {
+                var serializedValues = SerializeValues(serializationInfo, (IEnumerable)valuesExpression.Value);
+                return Query.In(serializationInfo.ElementName, serializedValues);
+            }
             return null;
         }
 

DriverUnitTests/Linq/SelectQueryTests.cs

@@ -1948,6 +1948,56 @@ where c.A.Any(a => a > 3)
             query.ToList(); // execute query
         }
 
+        [Test]
+        public void TestWhereLocalListContainsX()
+        {
+            var local = new List<int> { 1, 2, 3 };
+            
+            var query = from c in _collection.AsQueryable<C>()
+                        where local.Contains(c.X)
+                        select c;
+
+            var translatedQuery = MongoQueryTranslator.Translate(query);
+            Assert.IsInstanceOf<SelectQuery>(translatedQuery);
+            Assert.AreSame(_collection, translatedQuery.Collection);
+            Assert.AreSame(typeof(C), translatedQuery.DocumentType);
+
+            var selectQuery = (SelectQuery)translatedQuery;
+            Assert.AreEqual("(C c) => System.Collections.Generic.List`1[System.Int32].Contains(c.X)", ExpressionFormatter.ToString(selectQuery.Where));
+            Assert.IsNull(selectQuery.OrderBy);
+            Assert.IsNull(selectQuery.Projection);
+            Assert.IsNull(selectQuery.Skip);
+            Assert.IsNull(selectQuery.Take);
+
+            Assert.AreEqual("{ \"x\" : { \"$in\" : [1, 2, 3] } }", selectQuery.BuildQuery().ToJson());
+            Assert.AreEqual(3, Consume(query));
+        }
+
+        [Test]
+        public void TestWhereLocalArrayContainsX()
+        {
+            var local = new [] { 1, 2, 3 };
+
+            var query = from c in _collection.AsQueryable<C>()
+                        where local.Contains(c.X)
+                        select c;
+
+            var translatedQuery = MongoQueryTranslator.Translate(query);
+            Assert.IsInstanceOf<SelectQuery>(translatedQuery);
+            Assert.AreSame(_collection, translatedQuery.Collection);
+            Assert.AreSame(typeof(C), translatedQuery.DocumentType);
+
+            var selectQuery = (SelectQuery)translatedQuery;
+            Assert.AreEqual("(C c) => Enumerable.Contains<Int32>(Int32[]:{ 1, 2, 3 }, c.X)", ExpressionFormatter.ToString(selectQuery.Where));
+            Assert.IsNull(selectQuery.OrderBy);
+            Assert.IsNull(selectQuery.Projection);
+            Assert.IsNull(selectQuery.Skip);
+            Assert.IsNull(selectQuery.Take);
+
+            Assert.AreEqual("{ \"x\" : { \"$in\" : [1, 2, 3] } }", selectQuery.BuildQuery().ToJson());
+            Assert.AreEqual(3, Consume(query));
+        }
+
         [Test]
         public void TestWhereAContains2()
         {