Changes request-related events to async. Closes #200 (#224)

* Changes BeforeResponse to async event

* Updates all request-related events to async

---------

Co-authored-by: Gavin Barron <[email protected]>

Author: waldekmastykarz

msgraph-developer-proxy-abstractions/FuncExtensions.cs

@@ -0,0 +1,32 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+// from: https://github.com/justcoding121/titanium-web-proxy/blob/902504a324425e4e49fc5ba604c2b7fa172e68ce/src/Titanium.Web.Proxy/Extensions/FuncExtensions.cs
+
+using Titanium.Web.Proxy;
+using Titanium.Web.Proxy.EventArguments;
+
+namespace Microsoft.Graph.DeveloperProxy.Abstractions;
+
+public static class FuncExtensions
+{
+  internal static async Task InvokeAsync<T>(this AsyncEventHandler<T> callback, object sender, T args, ExceptionHandler? exceptionFunc)
+  {
+    var invocationList = callback.GetInvocationList();
+
+    foreach (var @delegate in invocationList)
+      await InternalInvokeAsync((AsyncEventHandler<T>)@delegate, sender, args, exceptionFunc);
+  }
+
+  private static async Task InternalInvokeAsync<T>(AsyncEventHandler<T> callback, object sender, T args, ExceptionHandler? exceptionFunc)
+  {
+    try
+    {
+      await callback(sender, args);
+    }
+    catch (Exception e)
+    {
+      exceptionFunc?.Invoke(new Exception("Exception thrown in user event", e));
+    }
+  }
+}

msgraph-developer-proxy-abstractions/PluginEvents.cs

@@ -96,18 +96,18 @@ public interface IPluginEvents {
     /// Raised before a request is sent to the server.
     /// Used to intercept requests.
     /// </summary>
-    event EventHandler<ProxyRequestArgs> BeforeRequest;
+    event AsyncEventHandler<ProxyRequestArgs> BeforeRequest;
     /// <summary>
     /// Raised after the response is received from the server.
     /// Is not raised if a response is set during the BeforeRequest event.
     /// Allows plugins to modify a response received from the server.
     /// </summary>
-    event EventHandler<ProxyResponseArgs> BeforeResponse;
+    event AsyncEventHandler<ProxyResponseArgs> BeforeResponse;
     /// <summary>
     /// Raised after a response is sent to the client.
     /// Raised for all responses
     /// </summary>
-    event EventHandler<ProxyResponseArgs>? AfterResponse;
+    event AsyncEventHandler<ProxyResponseArgs>? AfterResponse;
     /// <summary>
     /// Raised after request message has been logged.
     /// </summary>
@@ -124,11 +124,11 @@ public class PluginEvents : IPluginEvents {
     /// <inheritdoc />
     public event EventHandler<OptionsLoadedArgs>? OptionsLoaded;
     /// <inheritdoc />
-    public event EventHandler<ProxyRequestArgs>? BeforeRequest;
+    public event AsyncEventHandler<ProxyRequestArgs>? BeforeRequest;
     /// <inheritdoc />
-    public event EventHandler<ProxyResponseArgs>? BeforeResponse;
+    public event AsyncEventHandler<ProxyResponseArgs>? BeforeResponse;
     /// <inheritdoc />
-    public event EventHandler<ProxyResponseArgs>? AfterResponse;
+    public event AsyncEventHandler<ProxyResponseArgs>? AfterResponse;
     /// <inheritdoc />
     public event EventHandler<RequestLogArgs>? AfterRequestLog;
     /// <inheritdoc />
@@ -146,8 +146,8 @@ public void RaiseProxyBeforeRequest(ProxyRequestArgs args) {
         BeforeRequest?.Invoke(this, args);
     }
 
-    public void RaiseProxyBeforeResponse(ProxyResponseArgs args) {
-        BeforeResponse?.Invoke(this, args);
+    public async Task RaiseProxyBeforeResponse(ProxyResponseArgs args) {
+        await BeforeResponse?.InvokeAsync(this, args, null);
     }
 
     public void RaiseProxyAfterResponse(ProxyResponseArgs args) {

msgraph-developer-proxy-plugins/Guidance/GraphBetaSupportGuidancePlugin.cs

@@ -20,7 +20,7 @@ public override void Register(IPluginEvents pluginEvents,
         pluginEvents.AfterResponse += AfterResponse;
     }
 
-    private void AfterResponse(object? sender, ProxyResponseArgs e) {
+    private async Task AfterResponse(object? sender, ProxyResponseArgs e) {
         Request request = e.Session.HttpClient.Request;
         if (_urlsToWatch is not null &&
             e.HasRequestUrlMatch(_urlsToWatch) &&

msgraph-developer-proxy-plugins/Guidance/GraphClientRequestIdGuidancePlugin.cs

@@ -22,7 +22,7 @@ public override void Register(IPluginEvents pluginEvents,
     pluginEvents.BeforeRequest += BeforeRequest;
   }
 
-  private void BeforeRequest(object? sender, ProxyRequestArgs e)
+  private async Task BeforeRequest(object? sender, ProxyRequestArgs e)
   {
     Request request = e.Session.HttpClient.Request;
     if (_urlsToWatch is not null && e.HasRequestUrlMatch(_urlsToWatch) && WarnNoClientRequestId(request))

msgraph-developer-proxy-plugins/Guidance/GraphSdkGuidancePlugin.cs

@@ -20,7 +20,7 @@ public override void Register(IPluginEvents pluginEvents,
         pluginEvents.AfterResponse += OnAfterResponse;
     }
 
-    private void OnAfterResponse(object? sender, ProxyResponseArgs e) {
+    private async Task OnAfterResponse(object? sender, ProxyResponseArgs e) {
         Request request = e.Session.HttpClient.Request;
         // only show the message if there is an error.
         if (e.Session.HttpClient.Response.StatusCode >= 400 

msgraph-developer-proxy-plugins/Guidance/GraphSelectGuidancePlugin.cs

@@ -20,7 +20,7 @@ public override void Register(IPluginEvents pluginEvents,
         pluginEvents.AfterResponse += AfterResponse;
     }
 
-    private void AfterResponse(object? sender, ProxyResponseArgs e) {
+    private async Task AfterResponse(object? sender, ProxyResponseArgs e) {
         Request request = e.Session.HttpClient.Request;
         if (_urlsToWatch is not null && e.HasRequestUrlMatch(_urlsToWatch) && WarnNoSelect(request))
             _logger?.LogRequest(BuildUseSelectMessage(request), MessageType.Warning, new LoggingContext(e.Session));

msgraph-developer-proxy-plugins/Guidance/ODataPagingGuidancePlugin.cs

@@ -25,7 +25,7 @@ public override void Register(IPluginEvents pluginEvents,
     pluginEvents.BeforeResponse += OnBeforeResponse;
   }
 
-  private void OnBeforeRequest(object? sender, ProxyRequestArgs e)
+  private async Task OnBeforeRequest(object? sender, ProxyRequestArgs e)
   {
     if (_urlsToWatch is null ||
         e.Session.HttpClient.Request.Method != "GET" ||
@@ -41,7 +41,7 @@ private void OnBeforeRequest(object? sender, ProxyRequestArgs e)
     }
   }
 
-  private async void OnBeforeResponse(object? sender, ProxyResponseArgs e)
+  private async Task OnBeforeResponse(object? sender, ProxyResponseArgs e)
   {
     if (_urlsToWatch is null ||
         !e.HasRequestUrlMatch(_urlsToWatch) ||

msgraph-developer-proxy-plugins/MockResponses/MockResponsePlugin.cs

@@ -80,7 +80,7 @@ private void OnOptionsLoaded(object? sender, OptionsLoadedArgs e) {
         _loader?.InitResponsesWatcher();
     }
 
-    private void OnRequest(object? sender, ProxyRequestArgs e) {
+    private async Task OnRequest(object? sender, ProxyRequestArgs e) {
         Request request = e.Session.HttpClient.Request;
         ResponseState state = e.ResponseState;
         if (!_configuration.NoMocks && _urlsToWatch is not null && e.ShouldExecute(_urlsToWatch)) {

msgraph-developer-proxy-plugins/RandomErrors/GenericRandomErrorPlugin.cs

@@ -114,7 +114,7 @@ private void OnInit(object? sender, InitArgs e) {
         _loader?.InitResponsesWatcher();
     }
 
-    private void OnRequest(object? sender, ProxyRequestArgs e) {
+    private async Task OnRequest(object? sender, ProxyRequestArgs e) {
         var session = e.Session;
         var state = e.ResponseState;
         if (!e.ResponseState.HasBeenSet

msgraph-developer-proxy-plugins/RandomErrors/GraphRandomErrorPlugin.cs

@@ -205,7 +205,7 @@ private void OnOptionsLoaded(object? sender, OptionsLoadedArgs e) {
         }
     }
 
-    private void OnRequest(object? sender, ProxyRequestArgs e) {
+    private async Task OnRequest(object? sender, ProxyRequestArgs e) {
         var session = e.Session;
         var state = e.ResponseState;
         if (!e.ResponseState.HasBeenSet