CSHARP-5512: Convert LINQ-related tests to use fixtures. (#1627)

Author: sanych-sun

Diff for: CSharpDriver.sln.DotSettings

@@ -91,6 +91,10 @@ namespace $NAMESPACE$
 	<s:String x:Key="/Default/PatternsAndTemplates/LiveTemplates/Template/=58D5EB70DF984241A0863E67D7E33F3D/Field/=CLASS/Expression/@EntryValue">getAlphaNumericFileNameWithoutExtension()</s:String>
 	<s:Int64 x:Key="/Default/PatternsAndTemplates/LiveTemplates/Template/=58D5EB70DF984241A0863E67D7E33F3D/Field/=CLASS/InitialRange/@EntryValue">-1</s:Int64>
 	<s:Int64 x:Key="/Default/PatternsAndTemplates/LiveTemplates/Template/=58D5EB70DF984241A0863E67D7E33F3D/Field/=CLASS/Order/@EntryValue">0</s:Int64>
+	<s:Boolean x:Key="/Default/PatternsAndTemplates/LiveTemplates/Template/=58D5EB70DF984241A0863E67D7E33F3D/Field/=CLASS2/@KeyIndexDefined">True</s:Boolean>
+	<s:String x:Key="/Default/PatternsAndTemplates/LiveTemplates/Template/=58D5EB70DF984241A0863E67D7E33F3D/Field/=CLASS2/Expression/@EntryValue">typeName()</s:String>
+	<s:Int64 x:Key="/Default/PatternsAndTemplates/LiveTemplates/Template/=58D5EB70DF984241A0863E67D7E33F3D/Field/=CLASS2/InitialRange/@EntryValue">-1</s:Int64>
+	<s:Int64 x:Key="/Default/PatternsAndTemplates/LiveTemplates/Template/=58D5EB70DF984241A0863E67D7E33F3D/Field/=CLASS2/Order/@EntryValue">2</s:Int64>
 	<s:Boolean x:Key="/Default/PatternsAndTemplates/LiveTemplates/Template/=58D5EB70DF984241A0863E67D7E33F3D/Field/=NAMESPACE/@KeyIndexDefined">True</s:Boolean>
 	<s:String x:Key="/Default/PatternsAndTemplates/LiveTemplates/Template/=58D5EB70DF984241A0863E67D7E33F3D/Field/=NAMESPACE/Expression/@EntryValue">fileDefaultNamespace()</s:String>
 	<s:Int64 x:Key="/Default/PatternsAndTemplates/LiveTemplates/Template/=58D5EB70DF984241A0863E67D7E33F3D/Field/=NAMESPACE/InitialRange/@EntryValue">-1</s:Int64>
@@ -117,11 +121,12 @@ namespace $NAMESPACE$
 
 using System.Collections.Generic;
 using MongoDB.Driver.TestHelpers;
+using FluentAssertions;
 using Xunit;
 
 namespace $NAMESPACE$
 {
-    public class $CLASS$ : LinqIntegrationTest&lt;$CLASS$.ClassFixture&gt;
+    public class $CLASS$ : LinqIntegrationTest&lt;$CLASS2$.ClassFixture&gt;
     {
         public $CLASS$(ClassFixture fixture)
             : base(fixture)

Diff for: tests/MongoDB.Driver.TestHelpers/MongoCollectionFixture.cs

@@ -19,7 +19,11 @@
 
 namespace MongoDB.Driver.TestHelpers
 {
-    public abstract class MongoCollectionFixture<TDocument> : MongoDatabaseFixture
+    public abstract class MongoCollectionFixture<TDocument> : MongoCollectionFixture<TDocument, TDocument>
+    {
+    }
+
+    public abstract class MongoCollectionFixture<TDocument, TInitial> : MongoDatabaseFixture
     {
         private readonly Lazy<IMongoCollection<TDocument>> _collection;
         private bool _dataInitialized;
@@ -31,7 +35,7 @@ protected MongoCollectionFixture()
 
         public IMongoCollection<TDocument> Collection => _collection.Value;
 
-        protected abstract IEnumerable<TDocument> InitialData { get; }
+        protected abstract IEnumerable<TInitial> InitialData { get; }
 
         public virtual bool InitializeDataBeforeEachTestCase => false;
 
@@ -47,7 +51,8 @@ protected override void InitializeTestCase()
                 }
                 else
                 {
-                    Collection.InsertMany(InitialData);
+                    var collection = Database.GetCollection<TInitial>(Collection.CollectionNamespace.CollectionName);
+                    collection.InsertMany(InitialData);
                 }
 
                 _dataInitialized = true;