nullable annotation and extraction of RaisesAsync from modified `As…

…sert` class to new `MyAssert` class. (#249)

TwitchLib.Client.Test/CommandInfoTest.cs

@@ -11,7 +11,7 @@ public class CommandInfoTest
     [InlineData("! command")]
     public void ParsingFailAndReturnNull(string s)
     {
-        Assert.False(CommandInfo.TryParse(s, out CommandInfo commandInfo));
+        Assert.False(CommandInfo.TryParse(s, out var commandInfo));
         Assert.Null(commandInfo);
     }
 }

TwitchLib.Client.Test/MockIClient.cs

@@ -2,6 +2,7 @@
 using System.Threading.Tasks;
 using TwitchLib.Communication.Events;
 using TwitchLib.Communication.Interfaces;
+using TwitchLib.Communication.Models;
 
 namespace TwitchLib.Client.Test
 {
@@ -12,17 +13,17 @@ public class MockIClient : IClient
         public int SendQueueLength => throw new NotImplementedException();
 
         public bool IsConnected { get; private set; }
-        public IClientOptions Options { get; set; }
+        public IClientOptions Options { get; set; } = new ClientOptions();
 
         public int WhisperQueueLength => throw new NotImplementedException();
 
-        public event AsyncEventHandler<OnConnectedEventArgs> OnConnected;
-        public event AsyncEventHandler<OnDisconnectedEventArgs> OnDisconnected;
-        public event AsyncEventHandler<OnErrorEventArgs> OnError;
-        public event AsyncEventHandler<OnFatalErrorEventArgs> OnFatality;
-        public event AsyncEventHandler<OnMessageEventArgs> OnMessage;
-        public event AsyncEventHandler<OnSendFailedEventArgs> OnSendFailed;
-        public event AsyncEventHandler<OnConnectedEventArgs> OnReconnected;
+        public event AsyncEventHandler<OnConnectedEventArgs>? OnConnected;
+        public event AsyncEventHandler<OnDisconnectedEventArgs>? OnDisconnected;
+        public event AsyncEventHandler<OnErrorEventArgs>? OnError;
+        public event AsyncEventHandler<OnFatalErrorEventArgs>? OnFatality;
+        public event AsyncEventHandler<OnMessageEventArgs>? OnMessage;
+        public event AsyncEventHandler<OnSendFailedEventArgs>? OnSendFailed;
+        public event AsyncEventHandler<OnConnectedEventArgs>? OnReconnected;
 
         public Task CloseAsync()
         {
@@ -34,20 +35,19 @@ public Task CloseAsync()
         public void Dispose()
         { }
 
-        public void Dispose(bool waitForSendsToComplete)
-        { }
-
         public async Task<bool> OpenAsync()
         {
             IsConnected = true;
-            await OnConnected?.Invoke(this, new OnConnectedEventArgs());
+            if (OnConnected is not  null)
+                await OnConnected.Invoke(this, new OnConnectedEventArgs());
             return true;
         }
 
         public async Task<bool> ReconnectAsync()
         {
             IsConnected = true;
-            await OnReconnected?.Invoke(this, new OnConnectedEventArgs());
+            if (OnReconnected is not null)
+                await OnReconnected.Invoke(this, new OnConnectedEventArgs());
             return true;
         }
 
@@ -68,9 +68,8 @@ public Task<bool> SendAsync(string data)
 
         public async Task ReceiveMessage(string message)
         {
-
-           await OnMessage?.Invoke(this, new OnMessageEventArgs(message));
-
+            if (OnMessage is not null)
+                await OnMessage.Invoke(this, new OnMessageEventArgs(message));
         }
 
         public bool SendWhisper(string data)

TwitchLib.Client.Test/MyAssert.cs

@@ -0,0 +1,99 @@
+using System;
+using Xunit;
+using TwitchLib.Communication.Events;
+using System.Threading.Tasks;
+using Xunit.Sdk;
+
+namespace TwitchLib.Client.Test;
+
+//TL;DR: XUNIT with modification to accept async event Handler
+public partial class MyAssert
+{
+    /// <summary>
+    /// Verifies that a event with the exact event args (and not a derived type) is raised.
+    /// </summary>
+    /// <typeparam name="T">The type of the event arguments to expect</typeparam>
+    /// <param name="attach">Code to attach the event handler</param>
+    /// <param name="detach">Code to detach the event handler</param>
+    /// <param name="testCode">A delegate to the code to be tested</param>
+    /// <returns>The event sender and arguments wrapped in an object</returns>
+    /// <exception cref="RaisesException">Thrown when the expected event was not raised.</exception>
+    public static async Task<RaisedEvent<T>> RaisesAsync<T>(Action<AsyncEventHandler<T>> attach, Action<AsyncEventHandler<T>> detach, Func<Task> testCode)
+    {
+        var raisedEvent = await RaisesAsyncInternal(attach, detach, testCode);
+
+        if (raisedEvent == null)
+            throw new RaisesException(typeof(T));
+
+        if (raisedEvent.Arguments != null && !raisedEvent.Arguments.GetType().Equals(typeof(T)))
+            throw new RaisesException(typeof(T), raisedEvent.Arguments.GetType());
+
+        return raisedEvent;
+    }
+
+    /// <summary>
+    /// Verifies that an event with the exact or a derived event args is raised.
+    /// </summary>
+    /// <typeparam name="T">The type of the event arguments to expect</typeparam>
+    /// <param name="attach">Code to attach the event handler</param>
+    /// <param name="detach">Code to detach the event handler</param>
+    /// <param name="testCode">A delegate to the code to be tested</param>
+    /// <returns>The event sender and arguments wrapped in an object</returns>
+    /// <exception cref="RaisesException">Thrown when the expected event was not raised.</exception>
+    public static async Task<RaisedEvent<T>> RaisesAnyAsync<T>(Action<AsyncEventHandler<T>> attach, Action<AsyncEventHandler<T>> detach, Func<Task> testCode)
+    {
+        var raisedEvent = await RaisesAsyncInternal(attach, detach, testCode);
+
+        if (raisedEvent == null)
+            throw new RaisesException(typeof(T));
+
+        return raisedEvent;
+    }
+
+    static async Task<RaisedEvent<T>?> RaisesAsyncInternal<T>(Action<AsyncEventHandler<T>> attach, Action<AsyncEventHandler<T>> detach, Func<Task> testCode)
+    {
+        Assert.NotNull(attach);
+        Assert.NotNull(detach);
+        Assert.NotNull(testCode);
+
+        RaisedEvent<T>? raisedEvent = null;
+        AsyncEventHandler<T> value = (object? s, T args) =>
+        {
+            raisedEvent = new RaisedEvent<T>(s, args);
+            return Task.CompletedTask;
+        };
+        AsyncEventHandler<T> handler = value;
+        attach(handler);
+        await testCode();
+        detach(handler);
+        return raisedEvent;
+    }
+
+    /// <summary>
+    /// Represents a raised event after the fact.
+    /// </summary>
+    /// <typeparam name="T">The type of the event arguments.</typeparam>
+    public class RaisedEvent<T>
+    {
+        /// <summary>
+        /// The sender of the event.
+        /// </summary>
+        public object? Sender { get; }
+
+        /// <summary>
+        /// The event arguments.
+        /// </summary>
+        public T Arguments { get; }
+
+        /// <summary>
+        /// Creates a new instance of the <see cref="RaisedEvent{T}" /> class.
+        /// </summary>
+        /// <param name="sender">The sender of the event.</param>
+        /// <param name="args">The event arguments</param>
+        public RaisedEvent(object? sender, T args)
+        {
+            Sender = sender;
+            Arguments = args;
+        }
+    }
+}

TwitchLib.Client.Test/ThrottlingServiceTests.cs

@@ -23,7 +23,7 @@ public void EnqueueMessageTests(bool isConnected, uint queueCapacity, bool withM
                 .Returns(isConnected);
             var client = clientMock.Object;
             var throttlerService = new ThrottlingService(client, sendOptions);
-            OutboundChatMessage message = null;
+            OutboundChatMessage? message = null;
 
             if (withMessage)
             {