CSHARP-4317: Added integration test demonstrating that CSHARP-4316 fix also resolved dictionary key/value projection issue. (mongodb#877)

Author: JamesKovacs

tests/MongoDB.Driver.Tests/Linq/Linq3ImplementationTests/Jira/CSharp4317Tests.cs

@@ -0,0 +1,68 @@
+/* Copyright 2010-present MongoDB 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.Collections.Generic;
+using System.Linq;
+using FluentAssertions;
+using MongoDB.Bson.Serialization.Attributes;
+using MongoDB.Bson.Serialization.Options;
+using MongoDB.Driver.Linq;
+using Xunit;
+
+namespace MongoDB.Driver.Tests.Linq.Linq3ImplementationTests.Jira
+{
+    public class CSharp4317Tests : Linq3IntegrationTest
+    {
+        [Fact]
+        public void Projection_of_ArrayOfDocuments_dictionary_keys_and_values_should_work()
+        {
+            var collection = CreateCollection();
+            var projectStage = "{ $project : { Keys : '$Data.k', Values : '$Data.v', _id : 0 } }";
+
+            var queryable = collection
+                .AsQueryable()
+                .Select(x => new {
+                    Keys = x.Data.Select(y => y.Key),
+                    Values = x.Data.Select(y => y.Value)
+                });
+
+            var stages = Translate(collection, queryable);
+            AssertStages(stages, projectStage);
+
+            var result = queryable.First();
+            result.Keys.Should().Equal(1, 2);
+            result.Values.Should().Equal("v1", "v2");
+        }
+
+        private IMongoCollection<C> CreateCollection()
+        {
+            var collection = GetCollection<C>("C");
+
+            CreateCollection(
+                collection,
+                new C { Id = 1, Data = new Dictionary<int, string> { { 1, "v1" }, { 2, "v2" } } });
+
+            return collection;
+        }
+
+        private class C
+        {
+            public int Id { get; set; }
+
+            [BsonDictionaryOptions(DictionaryRepresentation.ArrayOfDocuments)]
+            public Dictionary<int, string> Data { get; set; }
+        }
+    }
+}