Object Explorer Service (#311)

* moving OE service from an old branch

test/Microsoft.SqlTools.ServiceLayer.UnitTests/ObjectExplorer/ObjectExplorerTestBase.cs

@@ -0,0 +1,45 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using Microsoft.SqlTools.Extensibility;
+using Microsoft.SqlTools.ServiceLayer.Connection;
+using Microsoft.SqlTools.ServiceLayer.ObjectExplorer;
+
+namespace Microsoft.SqlTools.ServiceLayer.UnitTests.ObjectExplorer
+{
+    // Base class providing common test functionality for OE tests
+    public abstract class ObjectExplorerTestBase
+    {
+        protected RegisteredServiceProvider ServiceProvider
+        {
+            get;
+            set;
+        }
+
+        protected RegisteredServiceProvider CreateServiceProviderWithMinServices()
+        {
+            return CreateProvider()
+                .RegisterSingleService(new ConnectionService())
+                .RegisterSingleService(new ObjectExplorerService());
+        }
+
+        protected RegisteredServiceProvider CreateProvider()
+        {
+            ServiceProvider = new RegisteredServiceProvider();
+            return ServiceProvider;
+        }
+        
+        protected ObjectExplorerService CreateOEService(ConnectionService connService)
+        {
+            CreateProvider()
+                .RegisterSingleService(connService)
+                .RegisterSingleService(new ObjectExplorerService());
+
+            // Create the service using the service provider, which will initialize dependencies
+            return ServiceProvider.GetService<ObjectExplorerService>();
+        }
+
+    }
+}