Merge previews/mockclients to master

iothub/service/src/DigitalTwin/DigitalTwinClient.cs

@@ -27,60 +27,12 @@ public class DigitalTwinClient : IDisposable
         private readonly IotHubGatewayServiceAPIs _client;
         private readonly PnpDigitalTwin _protocolLayer;
 
-        private DigitalTwinClient(string hostName, DigitalTwinServiceClientCredentials credentials, params DelegatingHandler[] handlers)
-        {
-            var httpsEndpoint = new UriBuilder(HttpsEndpointPrefix, hostName).Uri;
-            var httpMessageHandler = HttpClientHelper.CreateDefaultHttpMessageHandler(null, httpsEndpoint, ServicePointHelpers.DefaultConnectionLeaseTimeout);
-#pragma warning disable CA2000 // Dispose objects before losing scope (httpMessageHandlerWithDelegatingHandlers is disposed when the http client owning it is disposed)
-            HttpMessageHandler httpMessageHandlerWithDelegatingHandlers = CreateHttpHandlerPipeline(httpMessageHandler, handlers);
-#pragma warning restore CA2000 // Dispose objects before losing scope
-
-#pragma warning disable CA2000 // Dispose objects before losing scope (httpClient is disposed when the protocol layer client owning it is disposed)
-            var httpClient = new HttpClient(httpMessageHandlerWithDelegatingHandlers, true)
-            {
-                BaseAddress = httpsEndpoint
-            };
-#pragma warning restore CA2000 // Dispose objects before losing scope
-
-#pragma warning restore CA2000 // Dispose objects before losing scope
-
-            // When this client is disposed, all the http message handlers and delegating handlers will be disposed automatically
-            _client = new IotHubGatewayServiceAPIs(credentials, httpClient, true);
-            _client.BaseUri = httpsEndpoint;
-            _protocolLayer = new PnpDigitalTwin(_client);
-        }
-
-        // Creates a single HttpMessageHandler to construct a HttpClient with from a base httpMessageHandler and some number of custom delegating handlers
-        // This is almost a copy of the Microsoft.Rest.ClientRuntime library's implementation, but with the return and parameter type HttpClientHandler replaced
-        // with the more abstract HttpMessageHandler in order for us to set the base handler as either a SocketsHttpHandler for .net core or an HttpClientHandler otherwise
-        // https://github.com/Azure/azure-sdk-for-net/blob/99f4da88ab0aa01c79aa291c6c101ab94c4ac940/sdk/mgmtcommon/ClientRuntime/ClientRuntime/ServiceClient.cs#L376
-        private static HttpMessageHandler CreateHttpHandlerPipeline(HttpMessageHandler httpMessageHandler, params DelegatingHandler[] handlers)
+        /// <summary>
+        /// Creates an instance of <see cref="DigitalTwinClient"/>, provided for unit testing purposes only.
+        /// Use the CreateFromConnectionString or Create method to create an instance to use the client.
+        /// </summary>
+        public DigitalTwinClient()
         {
-            // The RetryAfterDelegatingHandler should be the absolute outermost handler
-            // because it's extremely lightweight and non-interfering
-            HttpMessageHandler currentHandler =
-#pragma warning disable CA2000 // Dispose objects before losing scope (delegating handler is disposed when the http client that uses it is disposed)
-                new RetryDelegatingHandler(new RetryAfterDelegatingHandler { InnerHandler = httpMessageHandler });
-#pragma warning restore CA2000 // Dispose objects before losing scope
-
-            if (handlers != null)
-            {
-                for (int i = handlers.Length - 1; i >= 0; --i)
-                {
-                    DelegatingHandler handler = handlers[i];
-                    // Non-delegating handlers are ignored since we always
-                    // have RetryDelegatingHandler as the outer-most handler
-                    while (handler.InnerHandler is DelegatingHandler)
-                    {
-                        handler = handler.InnerHandler as DelegatingHandler;
-                    }
-
-                    handler.InnerHandler = currentHandler;
-                    currentHandler = handlers[i];
-                }
-            }
-
-            return currentHandler;
         }
 
         /// <summary>
@@ -157,7 +109,7 @@ public static DigitalTwinClient CreateFromConnectionString(string connectionStri
         /// <param name="digitalTwinId">The Id of the digital twin.</param>
         /// <param name="cancellationToken">The cancellation token.</param>
         /// <returns>The application/json digital twin and the http response.</returns>
-        public async Task<HttpOperationResponse<T, DigitalTwinGetHeaders>> GetDigitalTwinAsync<T>(string digitalTwinId, CancellationToken cancellationToken = default)
+        public virtual async Task<HttpOperationResponse<T, DigitalTwinGetHeaders>> GetDigitalTwinAsync<T>(string digitalTwinId, CancellationToken cancellationToken = default)
         {
             using HttpOperationResponse<string, DigitalTwinGetHeaders> response = await _protocolLayer.GetDigitalTwinWithHttpMessagesAsync(digitalTwinId, null, cancellationToken)
                 .ConfigureAwait(false);
@@ -179,7 +131,7 @@ public static DigitalTwinClient CreateFromConnectionString(string connectionStri
         /// <param name="requestOptions">The optional settings for this request.</param>
         /// <param name="cancellationToken">The cancellationToken.</param>
         /// <returns>The http response.</returns>
-        public Task<HttpOperationHeaderResponse<DigitalTwinUpdateHeaders>> UpdateDigitalTwinAsync(
+        public virtual Task<HttpOperationHeaderResponse<DigitalTwinUpdateHeaders>> UpdateDigitalTwinAsync(
             string digitalTwinId,
             string digitalTwinUpdateOperations,
             DigitalTwinUpdateRequestOptions requestOptions = default,
@@ -197,7 +149,7 @@ public static DigitalTwinClient CreateFromConnectionString(string connectionStri
         /// <param name="requestOptions">The optional settings for this request.</param>
         /// <param name="cancellationToken">The cancellationToken.</param>
         /// <returns>The application/json command invocation response and the http response. </returns>
-        public async Task<HttpOperationResponse<DigitalTwinCommandResponse, DigitalTwinInvokeCommandHeaders>> InvokeCommandAsync(
+        public virtual async Task<HttpOperationResponse<DigitalTwinCommandResponse, DigitalTwinInvokeCommandHeaders>> InvokeCommandAsync(
             string digitalTwinId,
             string commandName,
             string payload = default,
@@ -232,7 +184,7 @@ public static DigitalTwinClient CreateFromConnectionString(string connectionStri
         /// <param name="requestOptions">The optional settings for this request.</param>
         /// <param name="cancellationToken">The cancellationToken.</param>
         /// <returns>The application/json command invocation response and the http response. </returns>
-        public async Task<HttpOperationResponse<DigitalTwinCommandResponse, DigitalTwinInvokeCommandHeaders>> InvokeComponentCommandAsync(
+        public virtual async Task<HttpOperationResponse<DigitalTwinCommandResponse, DigitalTwinInvokeCommandHeaders>> InvokeComponentCommandAsync(
             string digitalTwinId,
             string componentName,
             string commandName,
@@ -274,5 +226,61 @@ protected virtual void Dispose(bool disposing)
         {
             _client?.Dispose();
         }
+
+        private DigitalTwinClient(string hostName, DigitalTwinServiceClientCredentials credentials, params DelegatingHandler[] handlers)
+        {
+            var httpsEndpoint = new UriBuilder(HttpsEndpointPrefix, hostName).Uri;
+            var httpMessageHandler = HttpClientHelper.CreateDefaultHttpMessageHandler(null, httpsEndpoint, ServicePointHelpers.DefaultConnectionLeaseTimeout);
+#pragma warning disable CA2000 // Dispose objects before losing scope (httpMessageHandlerWithDelegatingHandlers is disposed when the http client owning it is disposed)
+            HttpMessageHandler httpMessageHandlerWithDelegatingHandlers = CreateHttpHandlerPipeline(httpMessageHandler, handlers);
+#pragma warning restore CA2000 // Dispose objects before losing scope
+
+#pragma warning disable CA2000 // Dispose objects before losing scope (httpClient is disposed when the protocol layer client owning it is disposed)
+            var httpClient = new HttpClient(httpMessageHandlerWithDelegatingHandlers, true)
+            {
+                BaseAddress = httpsEndpoint
+            };
+#pragma warning restore CA2000 // Dispose objects before losing scope
+
+#pragma warning restore CA2000 // Dispose objects before losing scope
+
+            // When this client is disposed, all the http message handlers and delegating handlers will be disposed automatically
+            _client = new IotHubGatewayServiceAPIs(credentials, httpClient, true);
+            _client.BaseUri = httpsEndpoint;
+            _protocolLayer = new PnpDigitalTwin(_client);
+        }
+
+        // Creates a single HttpMessageHandler to construct a HttpClient with from a base httpMessageHandler and some number of custom delegating handlers
+        // This is almost a copy of the Microsoft.Rest.ClientRuntime library's implementation, but with the return and parameter type HttpClientHandler replaced
+        // with the more abstract HttpMessageHandler in order for us to set the base handler as either a SocketsHttpHandler for .net core or an HttpClientHandler otherwise
+        // https://github.com/Azure/azure-sdk-for-net/blob/99f4da88ab0aa01c79aa291c6c101ab94c4ac940/sdk/mgmtcommon/ClientRuntime/ClientRuntime/ServiceClient.cs#L376
+        private static HttpMessageHandler CreateHttpHandlerPipeline(HttpMessageHandler httpMessageHandler, params DelegatingHandler[] handlers)
+        {
+            // The RetryAfterDelegatingHandler should be the absolute outermost handler
+            // because it's extremely lightweight and non-interfering
+            HttpMessageHandler currentHandler =
+#pragma warning disable CA2000 // Dispose objects before losing scope (delegating handler is disposed when the http client that uses it is disposed)
+                new RetryDelegatingHandler(new RetryAfterDelegatingHandler { InnerHandler = httpMessageHandler });
+#pragma warning restore CA2000 // Dispose objects before losing scope
+
+            if (handlers != null)
+            {
+                for (int i = handlers.Length - 1; i >= 0; --i)
+                {
+                    DelegatingHandler handler = handlers[i];
+                    // Non-delegating handlers are ignored since we always
+                    // have RetryDelegatingHandler as the outer-most handler
+                    while (handler.InnerHandler is DelegatingHandler)
+                    {
+                        handler = handler.InnerHandler as DelegatingHandler;
+                    }
+
+                    handler.InnerHandler = currentHandler;
+                    currentHandler = handlers[i];
+                }
+            }
+
+            return currentHandler;
+        }
     }
 }