Adds support for intercepting OPTIONS requests. Closes #411 (#415)

Author: waldekmastykarz

dev-proxy-plugins/Behavior/RetryAfterPlugin.cs

@@ -29,6 +29,7 @@ private Task OnRequest(object? sender, ProxyRequestArgs e)
   {
     if (e.ResponseState.HasBeenSet ||
         _urlsToWatch is null ||
+        e.Session.HttpClient.Request.Method.ToUpper() == "OPTIONS" ||
         !e.ShouldExecute(_urlsToWatch))
     {
       return Task.CompletedTask;

dev-proxy-plugins/Guidance/CachingGuidancePlugin.cs

@@ -31,7 +31,9 @@ public override void Register(IPluginEvents pluginEvents,
 
   private Task BeforeRequest(object? sender, ProxyRequestArgs e)
   {
-    if (_urlsToWatch is null || !e.HasRequestUrlMatch(_urlsToWatch))
+    if (_urlsToWatch is null ||
+      !e.HasRequestUrlMatch(_urlsToWatch) ||
+      e.Session.HttpClient.Request.Method.ToUpper() == "OPTIONS")
     {
       return Task.CompletedTask;
     }

dev-proxy-plugins/Guidance/GraphBetaSupportGuidancePlugin.cs

@@ -24,6 +24,7 @@ private Task AfterResponse(object? sender, ProxyResponseArgs e)
         Request request = e.Session.HttpClient.Request;
         if (_urlsToWatch is not null &&
             e.HasRequestUrlMatch(_urlsToWatch) &&
+            e.Session.HttpClient.Request.Method.ToUpper() != "OPTIONS" &&
             ProxyUtils.IsGraphBetaRequest(request))
             _logger?.LogRequest(BuildBetaSupportMessage(request), MessageType.Warning, new LoggingContext(e.Session));
         return Task.CompletedTask;

dev-proxy-plugins/Guidance/GraphClientRequestIdGuidancePlugin.cs

@@ -24,7 +24,10 @@ public override void Register(IPluginEvents pluginEvents,
   private Task BeforeRequest(object? sender, ProxyRequestArgs e)
   {
     Request request = e.Session.HttpClient.Request;
-    if (_urlsToWatch is not null && e.HasRequestUrlMatch(_urlsToWatch) && WarnNoClientRequestId(request))
+    if (_urlsToWatch is not null &&
+      e.HasRequestUrlMatch(_urlsToWatch) &&
+      e.Session.HttpClient.Request.Method.ToUpper() != "OPTIONS" &&
+      WarnNoClientRequestId(request))
     {
       _logger?.LogRequest(BuildAddClientRequestIdMessage(request), MessageType.Warning, new LoggingContext(e.Session));
 

dev-proxy-plugins/Guidance/GraphSdkGuidancePlugin.cs

@@ -23,10 +23,11 @@ private 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 
-            && _urlsToWatch is not null 
-            && e.HasRequestUrlMatch(_urlsToWatch) 
-            && WarnNoSdk(request)) {
+        if (e.Session.HttpClient.Response.StatusCode >= 400  &&
+            _urlsToWatch is not null &&
+            e.HasRequestUrlMatch(_urlsToWatch) &&
+            e.Session.HttpClient.Request.Method.ToUpper() != "OPTIONS" &&
+            WarnNoSdk(request)) {
             _logger?.LogRequest(MessageUtils.BuildUseSdkForErrorsMessage(request), MessageType.Tip, new LoggingContext(e.Session));
         }
 

dev-proxy-plugins/Guidance/GraphSelectGuidancePlugin.cs

@@ -24,7 +24,10 @@ public override void Register(IPluginEvents pluginEvents,
     private Task AfterResponse(object? sender, ProxyResponseArgs e)
     {
         Request request = e.Session.HttpClient.Request;
-        if (_urlsToWatch is not null && e.HasRequestUrlMatch(_urlsToWatch) && WarnNoSelect(request))
+        if (_urlsToWatch is not null &&
+            e.HasRequestUrlMatch(_urlsToWatch) &&
+            e.Session.HttpClient.Request.Method.ToUpper() != "OPTIONS" &&
+            WarnNoSelect(request))
             _logger?.LogRequest(BuildUseSelectMessage(request), MessageType.Warning, new LoggingContext(e.Session));
 
         return Task.CompletedTask;

dev-proxy-plugins/Guidance/ODSPSearchGuidancePlugin.cs

@@ -24,7 +24,10 @@ public override void Register(IPluginEvents pluginEvents,
     private Task BeforeRequest(object sender, ProxyRequestArgs e)
     {
         Request request = e.Session.HttpClient.Request;
-        if (_urlsToWatch is not null && e.HasRequestUrlMatch(_urlsToWatch) && WarnDeprecatedSearch(request))
+        if (_urlsToWatch is not null &&
+            e.HasRequestUrlMatch(_urlsToWatch) &&
+            e.Session.HttpClient.Request.Method.ToUpper() != "OPTIONS" &&
+            WarnDeprecatedSearch(request))
             _logger?.LogRequest(BuildUseGraphSearchMessage(), MessageType.Warning, new LoggingContext(e.Session));
 
         return Task.CompletedTask;

dev-proxy/ProxyEngine.cs

@@ -352,9 +352,7 @@ private bool IsProxiedProcess(TunnelConnectSessionEventArgs e) {
   }
 
   async Task OnRequest(object sender, SessionEventArgs e) {
-        var method = e.HttpClient.Request.Method.ToUpper();
-        // The proxy does not intercept or alter OPTIONS requests
-        if (method is not "OPTIONS" && IsProxiedHost(e.HttpClient.Request.RequestUri.Host)) {
+        if (IsProxiedHost(e.HttpClient.Request.RequestUri.Host)) {
             // we need to keep the request body for further processing
             // by plugins
             e.HttpClient.Request.KeepBody = true;
@@ -386,20 +384,20 @@ private async Task HandleRequest(SessionEventArgs e) {
 
     // Modify response
     async Task OnBeforeResponse(object sender, SessionEventArgs e) {
-        var method = e.HttpClient.Request.Method.ToUpper();
         // read response headers
-        if (method is not "OPTIONS" && IsProxiedHost(e.HttpClient.Request.RequestUri.Host)) {
+        if (IsProxiedHost(e.HttpClient.Request.RequestUri.Host)) {
             // necessary to make the response body available to plugins
             e.HttpClient.Response.KeepBody = true;
-            await e.GetResponseBody();
+            if (e.HttpClient.Response.HasBody) {
+                await e.GetResponseBody();
+            }
 
             await _pluginEvents.RaiseProxyBeforeResponse(new ProxyResponseArgs(e, _throttledRequests, new ResponseState()));
         }
     }
     async Task OnAfterResponse(object sender, SessionEventArgs e) {
-        var method = e.HttpClient.Request.Method.ToUpper();
         // read response headers
-        if (method is not "OPTIONS" && IsProxiedHost(e.HttpClient.Request.RequestUri.Host)) {
+        if (IsProxiedHost(e.HttpClient.Request.RequestUri.Host)) {
             _logger.LogRequest(new[] { $"{e.HttpClient.Request.Method} {e.HttpClient.Request.Url}" }, MessageType.InterceptedResponse, new LoggingContext(e));
             await _pluginEvents.RaiseProxyAfterResponse(new ProxyResponseArgs(e, _throttledRequests, new ResponseState()));
         }