CSHARP-1906: Test that case insensitive searches work in LINQ. (#840)

Author: rstam

tests/MongoDB.Driver.Tests/Linq/Linq3ImplementationTests/Jira/CSharp1906Tests.cs

@@ -0,0 +1,78 @@
+/* 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;
+using System.Linq;
+using System.Text.RegularExpressions;
+using FluentAssertions;
+using MongoDB.Driver.Linq;
+using Xunit;
+
+namespace MongoDB.Driver.Tests.Linq.Linq3ImplementationTests.Jira
+{
+    public class CSharp1906Tests : Linq3IntegrationTest
+    {
+        [Fact]
+        public void Using_ToLower_should_work()
+        {
+            var collection = CreateCollection();
+            var lowerCaseValues = new[] { "abc", "def" }; // ensure all are lower case at compile time
+            var queryable = collection.AsQueryable()
+                .Where(c => lowerCaseValues.Contains(c.S.ToLower()));
+
+            var stages = Translate(collection, queryable);
+            AssertStages(stages, "{ $match : { $expr : { $in : [{ $toLower : '$S' }, ['abc', 'def']] } } }");
+
+            var results = queryable.ToList().OrderBy(x => x.Id).ToList();
+            results.Select(x => x.Id).Should().Equal(1, 2);
+        }
+
+        [Fact]
+        public void Using_regular_expression_should_work()
+        {
+            var collection = CreateCollection();
+            var regularExpresssion = new StringOrRegularExpression[] { new Regex("ABC", RegexOptions.IgnoreCase), new Regex("DEF", RegexOptions.IgnoreCase) };
+            var queryable = collection.AsQueryable()
+                .Where(c => c.S.StringIn(regularExpresssion));
+
+            var stages = Translate(collection, queryable);
+            AssertStages(stages, "{ $match : { S : { $in : [/ABC/i, /DEF/i] } } }");
+
+            var results = queryable.ToList().OrderBy(x => x.Id).ToList();
+            results.Select(x => x.Id).Should().Equal(1, 2);
+        }
+
+        private IMongoCollection<C> CreateCollection()
+        {
+            var collection = GetCollection<C>();
+
+            var documents = new[]
+            {
+                new C { Id = 1, S = "aBc" },
+                new C { Id = 2, S = "dEf" },
+                new C { Id = 3, S = "gHi" }
+            };
+            CreateCollection(collection, documents);
+
+            return collection;
+        }
+
+        public class C
+        {
+            public int Id { get; set; }
+            public string S { get; set; }
+        }
+    }
+}