CSHARP-1410: Allow $type to support string representations of type.

Author: rstam

src/MongoDB.Driver.Tests/FilterDefinitionBuilderTests.cs

@@ -816,6 +816,14 @@ public void Type()
             Assert(subject.Type("x", BsonType.String), "{x: {$type: 2}}");
         }
 
+        [Test]
+        public void Type_string()
+        {
+            var subject = CreateSubject<BsonDocument>();
+
+            Assert(subject.Type("x", "string"), "{x: {$type: \"string\"}}");
+        }
+
         [Test]
         public void Type_Typed()
         {
@@ -824,6 +832,14 @@ public void Type_Typed()
             Assert(subject.Type("FirstName", BsonType.String), "{fn: {$type: 2}}");
         }
 
+        [Test]
+        public void Type_Typed_string()
+        {
+            var subject = CreateSubject<Person>();
+            Assert(subject.Type(x => x.FirstName, "string"), "{fn: {$type: \"string\"}}");
+            Assert(subject.Type("FirstName", "string"), "{fn: {$type: \"string\"}}");
+        }
+
         private void Assert<TDocument>(FilterDefinition<TDocument> filter, string expected)
         {
             Assert(filter, BsonDocument.Parse(expected));

src/MongoDB.Driver/FilterDefinitionBuilder.cs

@@ -1144,6 +1144,17 @@ public FilterDefinition<TDocument> Type(FieldDefinition<TDocument> field, BsonTy
             return new OperatorFilterDefinition<TDocument>("$type", field, (int)type);
         }
 
+        /// <summary>
+        /// Creates a type filter.
+        /// </summary>
+        /// <param name="field">The field.</param>
+        /// <param name="type">The type.</param>
+        /// <returns>A type filter.</returns>
+        public FilterDefinition<TDocument> Type(FieldDefinition<TDocument> field, string type)
+        {
+            return new OperatorFilterDefinition<TDocument>("$type", field, type);
+        }
+
         /// <summary>
         /// Creates a type filter.
         /// </summary>
@@ -1154,6 +1165,16 @@ public FilterDefinition<TDocument> Type(Expression<Func<TDocument, object>> fiel
         {
             return Type(new ExpressionFieldDefinition<TDocument>(field), type);
         }
+        /// <summary>
+        /// Creates a type filter.
+        /// </summary>
+        /// <param name="field">The field.</param>
+        /// <param name="type">The type.</param>
+        /// <returns>A type filter.</returns>
+        public FilterDefinition<TDocument> Type(Expression<Func<TDocument, object>> field, string type)
+        {
+            return Type(new ExpressionFieldDefinition<TDocument>(field), type);
+        }
 
         /// <summary>
         /// Creates a filter based on the expression.