Improve code coverage DevicesClient V2 (#3073)

* Add more unit tests

* Address comments

* Create new tests

* Work in progress

* Work in progress

* Work in progress

* Add more unit tests

* Make methods virtual and write more unit test cases

* Add more test

* Add comment

* Rename test case

* remove extra line

* remove extra line

* Address comments

* Add comments

iothub/service/src/Amqp/AmqpConnectionHandler.cs

@@ -41,6 +41,12 @@ internal class AmqpConnectionHandler : IDisposable
 
         // The current delivery tag. Increments after each send operation to give a unique value.
         private int _sendingDeliveryTag;
+
+        /// <summary>
+        /// Creates an instance of this class. Provided for unit testing purposes only.
+        /// </summary>
+        protected internal AmqpConnectionHandler()
+        { }
 
         internal AmqpConnectionHandler(
             IotHubConnectionProperties credential,
@@ -64,9 +70,10 @@ internal AmqpConnectionHandler(
         /// <summary>
         /// Returns true if this connection, its sessions and its sessions' links are all open.
         /// Returns false otherwise.
+        /// Marked virtual for unit testing purposes only.
         /// </summary>
         /// <returns>True if this connection, its sessions and its sessions' links are all open. False otherwise.</returns>
-        internal bool IsOpen => _connection != null
+        internal virtual bool IsOpen => _connection != null
             && _connection.State == AmqpObjectState.Opened
             && _cbsSession != null
             && _cbsSession.IsOpen()
@@ -76,9 +83,10 @@ internal AmqpConnectionHandler(
         /// <summary>
         /// Opens the AMQP connection. This involves creating the needed TCP or Websocket transport and
         /// then opening all the required sessions and links.
+        /// Marked virtual for unit testing purposes only.
         /// </summary>
         /// <param name="cancellationToken">The cancellation token.</param>
-        internal async Task OpenAsync(CancellationToken cancellationToken)
+        internal virtual async Task OpenAsync(CancellationToken cancellationToken)
         {
             if (Logging.IsEnabled)
                 Logging.Enter(this, "Opening amqp connection.", nameof(OpenAsync));
@@ -185,9 +193,10 @@ internal async Task OpenAsync(CancellationToken cancellationToken)
 
         /// <summary>
         /// Closes the AMQP connection. This closes all the open links and sessions prior to closing the connection.
+        /// Marked virtual for unit testing purposes only.
         /// </summary>
         /// <param name="cancellationToken">The cancellation token.</param>
-        internal async Task CloseAsync(CancellationToken cancellationToken)
+        internal virtual async Task CloseAsync(CancellationToken cancellationToken)
         {
             if (Logging.IsEnabled)
                 Logging.Enter(this, "Closing amqp connection.", nameof(CloseAsync));
@@ -233,7 +242,7 @@ internal async Task CloseAsync(CancellationToken cancellationToken)
         /// </summary>
         /// <param name="message">The message to send.</param>
         /// <param name="cancellationToken">The cancellation token.</param>
-        internal async Task<Outcome> SendAsync(AmqpMessage message, CancellationToken cancellationToken)
+        internal virtual async Task<Outcome> SendAsync(AmqpMessage message, CancellationToken cancellationToken)
         {
             ArraySegment<byte> deliveryTag = GetNextDeliveryTag();
             return await _workerSession.SendAsync(message, deliveryTag, cancellationToken).ConfigureAwait(false);

iothub/service/src/Feedback/MessageFeedbackProcessorClient.cs

@@ -29,6 +29,22 @@ public class MessageFeedbackProcessorClient : IDisposable
         protected MessageFeedbackProcessorClient()
         { }
 
+        /// <summary>
+        /// Creates an instance of this class. Provided for unit testing purposes only.
+        /// </summary>
+        internal MessageFeedbackProcessorClient(
+            string hostName,
+            IotHubConnectionProperties credentialProvider,
+            IotHubServiceClientOptions options,
+            RetryHandler retryHandler,
+            AmqpConnectionHandler amqpConnection)
+        {
+            _hostName = hostName;
+            _credentialProvider = credentialProvider;
+            _internalRetryHandler = retryHandler;
+            _amqpConnection = amqpConnection;
+        }
+
         internal MessageFeedbackProcessorClient(
             string hostName,
             IotHubConnectionProperties credentialProvider,

iothub/service/src/FileUpload/FileUploadNotificationProcessorClient.cs

@@ -27,6 +27,21 @@ public class FileUploadNotificationProcessorClient : IDisposable
         protected FileUploadNotificationProcessorClient()
         { }
 
+        /// <summary>
+        /// Creates an instance of this class. Provided for unit testing purposes only.
+        /// </summary>
+        internal FileUploadNotificationProcessorClient(
+            string hostName,
+            IotHubConnectionProperties credentialProvider,
+            RetryHandler retryHandler,
+            AmqpConnectionHandler amqpConnection)
+        {
+            _hostName = hostName;
+            _credentialProvider = credentialProvider;
+            _internalRetryHandler = retryHandler;
+            _amqpConnection = amqpConnection;
+        }
+
         internal FileUploadNotificationProcessorClient(
             string hostName,
             IotHubConnectionProperties credentialProvider,

iothub/service/src/Messaging/MessagesClient.cs

@@ -38,6 +38,21 @@ protected MessagesClient()
         {
         }
 
+        /// <summary>
+        /// Creates an instance of this class. Provided for unit testing purposes only.
+        /// </summary>
+        internal MessagesClient(
+            string hostName,
+            IotHubConnectionProperties credentialProvider,
+            RetryHandler retryHandler,
+            AmqpConnectionHandler amqpConnection)
+        {
+            _hostName = hostName;
+            _credentialProvider = credentialProvider;
+            _internalRetryHandler = retryHandler;
+            _amqpConnection = amqpConnection;
+        }
+
         internal MessagesClient(
             string hostName,
             IotHubConnectionProperties credentialProvider,

iothub/service/src/Utilities/Logging.cs

@@ -4,13 +4,16 @@
 using System;
 using System.Collections;
 using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
 using System.Diagnostics.Tracing;
 using System.Globalization;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
 namespace Microsoft.Azure.Devices
 {
+    /// Logging is not part of the core functionality of the client, so we will not concern ourselves with code coverage of this class.
+    [ExcludeFromCodeCoverage]
     internal sealed partial class Logging : EventSource
     {
         /// <summary>The single event source instance to use for all logging.</summary>

iothub/service/tests/ConfigurationsClientTests.cs → iothub/service/tests/Configurations/ConfigurationsClientTests.cs

@@ -13,7 +13,7 @@
 using FluentAssertions;
 using Azure;
 
-namespace Microsoft.Azure.Devices.Tests
+namespace Microsoft.Azure.Devices.Tests.Configurations
 {
     [TestClass]
     [TestCategory("Unit")]
@@ -104,7 +104,7 @@ public async Task ConfigurationClients_CreateAsync_NullConfigurationThrows()
                 s_retryHandler);
 
             // act
-            Func<Task> act = async () => await configurationsClient.CreateAsync((Configuration)null).ConfigureAwait(false);
+            Func<Task> act = async () => await configurationsClient.CreateAsync(null).ConfigureAwait(false);
 
             // assert
             await act.Should().ThrowAsync<ArgumentNullException>().ConfigureAwait(false);
@@ -331,7 +331,7 @@ public async Task ConfigurationClients_SetAsync_NullConfigurationThrows()
                 s_retryHandler);
 
             // act
-            Func<Task> act = async () => await configurationsClient.SetAsync((Configuration)null).ConfigureAwait(false);
+            Func<Task> act = async () => await configurationsClient.SetAsync(null).ConfigureAwait(false);
 
             // assert
             await act.Should().ThrowAsync<ArgumentNullException>().ConfigureAwait(false);
@@ -385,7 +385,7 @@ public async Task ConfigurationClients_DeleteAsync()
         {
             // arrange
             string configurationId = Guid.NewGuid().ToString().ToLower(); // Configuration Id characters must be all lower-case.
-            var configuration= new Configuration(configurationId)
+            var configuration = new Configuration(configurationId)
             {
                 Priority = 1,
                 Labels = new Dictionary<string, string>
@@ -438,7 +438,7 @@ public async Task ConfigurationClients_DeleteAsync_NullConfigurationIdThrows()
                 s_retryHandler);
 
             // act
-            Func<Task> act = async () => await configurationsClient.DeleteAsync(null,false).ConfigureAwait(false);
+            Func<Task> act = async () => await configurationsClient.DeleteAsync(null, false).ConfigureAwait(false);
 
             // assert
             await act.Should().ThrowAsync<ArgumentNullException>().ConfigureAwait(false);
@@ -546,7 +546,7 @@ public async Task ConfigurationClients_ApplyConfigurationContentOnDeviceAsync_Em
                 s_retryHandler);
 
             // act
-            Func<Task> act = async () => await configurationsClient.ApplyConfigurationContentOnDeviceAsync(String.Empty, null).ConfigureAwait(false);
+            Func<Task> act = async () => await configurationsClient.ApplyConfigurationContentOnDeviceAsync(string.Empty, null).ConfigureAwait(false);
 
             // assert
             await act.Should().ThrowAsync<ArgumentException>().ConfigureAwait(false);

iothub/service/tests/Feedback/MessageFeedbackProcessorClientTests.cs

@@ -0,0 +1,73 @@
+// 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.Threading;
+using System.Threading.Tasks;
+using FluentAssertions;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace Microsoft.Azure.Devices.Tests.Feedback
+{
+    [TestClass]
+    [TestCategory("Unit")]
+    public class MessageFeedbackProcessorClientTests
+    {
+        private const string HostName = "contoso.azure-devices.net";
+        private static readonly string s_connectionString = $"HostName={HostName};SharedAccessKeyName=iothubowner;SharedAccessKey=dGVzdFN0cmluZzE=";
+
+        private static IIotHubServiceRetryPolicy noRetryPolicy = new IotHubServiceNoRetry();
+        private static IotHubServiceClientOptions s_options = new()
+        {
+            Protocol = IotHubTransportProtocol.Tcp,
+            RetryPolicy = noRetryPolicy
+        };
+
+        [TestMethod]
+        public async Task MessageFeedbackProcessorClient_OpenAsync_NotSettingMessageFeedbackProcessorThrows()
+        {
+            // arrange
+            using var serviceClient = new IotHubServiceClient(
+                s_connectionString,
+                s_options);
+
+            // act
+            Func<Task> act = async () => await serviceClient.MessageFeedback.OpenAsync().ConfigureAwait(false);
+
+            // assert
+            await act.Should().ThrowAsync<InvalidOperationException>();
+        }
+
+        [TestMethod]
+        public async Task MessageFeedbackProcessorClient_OpenAsync_Cancelled_ThrowsOperationCanceledException()
+        {
+            // arrange
+            using var serviceClient = new IotHubServiceClient(
+                s_connectionString,
+                s_options);
+
+            // act
+            var ct = new CancellationToken(true);
+            Func<Task> act = async () => await serviceClient.MessageFeedback.OpenAsync(ct);
+
+            // assert
+            await act.Should().ThrowAsync<OperationCanceledException>();
+        }
+
+        [TestMethod]
+        public async Task MessageFeedbackProcessorClient_CloseAsync_Cancelled_ThrowsOperationCanceledException()
+        {
+            // arrange
+            using var serviceClient = new IotHubServiceClient(
+                s_connectionString,
+                s_options);
+
+            // act
+            var ct = new CancellationToken(true);
+            Func<Task> act = async () => await serviceClient.MessageFeedback.CloseAsync(ct);
+
+            // assert
+            await act.Should().ThrowAsync<OperationCanceledException>();
+        }
+    }
+}