Add IComponentRegistry dependency container interface

This change adds a new interface called IComponentRegistry which acts as
a dependency container for components in PowerShell Editor Services.
It also adds a default ComponentRegistry class which implements this
interface so that it can be used in the server.

Author: daviwil

src/PowerShellEditorServices/Components/ComponentRegistry.cs

@@ -0,0 +1,80 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Microsoft.PowerShell.EditorServices.Components
+{
+    /// <summary>
+    /// Provides a default implementation for the IComponentRegistry
+    /// interface.
+    /// </summary>
+    public class ComponentRegistry : IComponentRegistry
+    {
+        private Dictionary<Type, object> componentRegistry =
+            new Dictionary<Type, object>();
+
+        /// <summary>
+        /// Registers an instance of the specified component type
+        /// or throws an ArgumentException if an instance has
+        /// already been registered.
+        /// </summary>
+        /// <param name="componentInstance">
+        /// The instance of the component to be registered.
+        /// </param>
+        /// <returns>
+        /// The provided component instance for convenience in assignment
+        /// statements.
+        /// </returns>
+        public TComponent Register<TComponent>(TComponent componentInstance)
+            where TComponent : class
+        {
+            this.componentRegistry.Add(typeof(TComponent), componentInstance);
+            return componentInstance;
+        }
+
+
+        /// <summary>
+        /// Gets the registered instance of the specified
+        /// component type or throws a KeyNotFoundException if
+        /// no instance has been registered.
+        /// </summary>
+        /// <returns>The implementation of the specified type.</returns>
+        public TComponent Get<TComponent>()
+            where TComponent : class
+        {
+            return (TComponent)this.componentRegistry[typeof(TComponent)];
+        }
+
+        /// <summary>
+        /// Attempts to retrieve the instance of the specified
+        /// component type and, if found, stores it in the
+        /// componentInstance parameter.
+        /// </summary>
+        /// <param name="componentInstance">
+        /// The out parameter in which the found instance will be stored.
+        /// </param>
+        /// <returns>
+        /// True if a registered instance was found, false otherwise.
+        /// </returns>
+        public bool TryGet<TComponent>(out TComponent componentInstance)
+            where TComponent : class
+        {
+            object componentObject = null;
+            componentInstance = null;
+
+            if (this.componentRegistry.TryGetValue(typeof(TComponent), out componentObject))
+            {
+                componentInstance = componentObject as TComponent;
+                return componentInstance != null;
+            }
+
+            return false;
+        }
+    }
+}

src/PowerShellEditorServices/Components/IComponentRegistry.cs

@@ -0,0 +1,55 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Microsoft.PowerShell.EditorServices.Components
+{
+    /// <summary>
+    /// Specifies the contract for a registry of component interfaces.
+    /// </summary>
+    public interface IComponentRegistry
+    {
+        /// <summary>
+        /// Registers an instance of the specified component type
+        /// or throws an ArgumentException if an instance has
+        /// already been registered.
+        /// </summary>
+        /// <param name="componentInstance">
+        /// The instance of the component to be registered.
+        /// </param>
+        /// <returns>
+        /// The provided component instance for convenience in assignment
+        /// statements.
+        /// </returns>
+        TComponent Register<TComponent>(TComponent componentInstance)
+            where TComponent : class;
+
+        /// <summary>
+        /// Gets the registered instance of the specified
+        /// component type or throws a KeyNotFoundException if
+        /// no instance has been registered.
+        /// </summary>
+        /// <returns>The implementation of the specified type.</returns>
+        TComponent Get<TComponent>()
+            where TComponent : class;
+
+        /// <summary>
+        /// Attempts to retrieve the instance of the specified
+        /// component type and, if found, stores it in the
+        /// componentInstance parameter.
+        /// </summary>
+        /// <param name="componentInstance">
+        /// The out parameter in which the found instance will be stored.
+        /// </param>
+        /// <returns>
+        /// True if a registered instance was found, false otherwise.
+        /// </returns>
+        bool TryGet<TComponent>(out TComponent componentInstance)
+            where TComponent : class;
+    }
+}

src/PowerShellEditorServices/Session/EditorSession.cs

@@ -3,6 +3,7 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
+using Microsoft.PowerShell.EditorServices.Components;
 using Microsoft.PowerShell.EditorServices.Console;
 using Microsoft.PowerShell.EditorServices.Extensions;
 using Microsoft.PowerShell.EditorServices.Session;
@@ -71,6 +72,11 @@ public class EditorSession
         /// </summary>
         public RemoteFileManager RemoteFileManager { get; private set; }
 
+        /// <summary>
+        /// Gets the IComponentCollection instance for this session.
+        /// </summary>
+        public IComponentRegistry Components { get; } = new ComponentRegistry();
+
         #endregion
 
         #region Constructors