Added Option to add Interceptors on Client Level

RestSharp.sln

@@ -35,7 +35,7 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "RestSharp.Tests.Serializers
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "SourceGen", "SourceGen", "{55B8F371-B2BA-4DEE-AB98-5BAB8A21B1C2}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SourceGenerator", "gen\SourceGenerator\SourceGenerator.csproj", "{FE778406-ADCF-45A1-B775-A054B55BFC50}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "SourceGenerator", "gen\SourceGenerator\SourceGenerator.csproj", "{FE778406-ADCF-45A1-B775-A054B55BFC50}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -446,6 +446,36 @@ Global
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 		{FE778406-ADCF-45A1-B775-A054B55BFC50}.Release|x86.Build.0 = Release|Any CPU
+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Debug.Appveyor|Any CPU.ActiveCfg = Debug|Any CPU
+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Debug.Appveyor|Any CPU.Build.0 = Debug|Any CPU
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+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Debug.Appveyor|ARM.Build.0 = Debug|Any CPU
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+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Debug.Appveyor|x64.Build.0 = Debug|Any CPU
+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Debug.Appveyor|x86.ActiveCfg = Debug|Any CPU
+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Debug.Appveyor|x86.Build.0 = Debug|Any CPU
+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Debug|ARM.ActiveCfg = Debug|Any CPU
+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Debug|ARM.Build.0 = Debug|Any CPU
+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Debug|Mixed Platforms.ActiveCfg = Debug|Any CPU
+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Debug|Mixed Platforms.Build.0 = Debug|Any CPU
+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Debug|x64.Build.0 = Debug|Any CPU
+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Debug|x86.Build.0 = Debug|Any CPU
+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Release|Any CPU.Build.0 = Release|Any CPU
+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Release|ARM.ActiveCfg = Release|Any CPU
+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Release|ARM.Build.0 = Release|Any CPU
+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Release|Mixed Platforms.ActiveCfg = Release|Any CPU
+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Release|Mixed Platforms.Build.0 = Release|Any CPU
+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Release|x64.ActiveCfg = Release|Any CPU
+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Release|x64.Build.0 = Release|Any CPU
+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Release|x86.ActiveCfg = Release|Any CPU
+		{5E8D472F-5A12-4CD8-8DBE-E3F6E0F76798}.Release|x86.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

gen/SourceGenerator/SourceGenerator.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
         <TargetFramework>netstandard2.0</TargetFramework>

src/RestSharp/Interceptors/Interceptor.cs

@@ -0,0 +1,57 @@
+//  Copyright (c) .NET Foundation and Contributors
+// 
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// 
+// http://www.apache.org/licenses/LICENSE-2.0
+// 
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// 
+
+namespace RestSharp.Interceptors; 
+
+/// <summary>
+/// Base Interceptor
+/// </summary>
+public abstract class Interceptor {
+    /// <summary>
+    /// Intercepts the request before serialization
+    /// </summary>
+    /// <param name="request">RestRequest before serialization</param>
+    /// <returns>Value Tags</returns>
+    public virtual ValueTask InterceptBeforeSerialization(RestRequest request) {
+        return new();
+    }
+
+    /// <summary>
+    /// Intercepts the request before being sent
+    /// </summary>
+    /// <param name="req">HttpRequestMessage before being sent</param>
+    /// <returns>Value Tags</returns>
+    public virtual ValueTask InterceptBeforeRequest(HttpRequestMessage req) {
+        return new();
+    }
+
+    /// <summary>
+    /// Intercepts the request before being sent
+    /// </summary>
+    /// <param name="responseMessage">HttpResponseMessage as received from Server</param>
+    /// <returns>Value Tags</returns>
+    public virtual ValueTask InterceptAfterRequest(HttpResponseMessage responseMessage) {
+        return new();
+    }
+
+    /// <summary>
+    /// Intercepts the request before deserialization
+    /// </summary>
+    /// <param name="response">HttpResponseMessage as received from Server</param>
+    /// <returns>Value Tags</returns>
+    public virtual ValueTask InterceptBeforeDeserialize(RestResponse response) {
+        return new();
+    }
+}

src/RestSharp/Options/RestClientOptions.cs

@@ -22,6 +22,7 @@
 using System.Text;
 using RestSharp.Authenticators;
 using RestSharp.Extensions;
+using RestSharp.Interceptors;
 
 // ReSharper disable UnusedAutoPropertyAccessor.Global
 // ReSharper disable PropertyCanBeMadeInitOnly.Global
@@ -64,6 +65,8 @@ public RestClientOptions(string baseUrl) : this(new Uri(Ensure.NotEmptyString(ba
     /// </summary>
     public IAuthenticator? Authenticator { get; set; }
 
+    public List<Interceptor> Interceptors { get; set; } = new();
+
     /// <summary>
     /// Passed to <see cref="HttpMessageHandler"/> <code>Credentials</code> property
     /// </summary>

src/RestSharp/RestClient.Async.cs

@@ -76,7 +76,7 @@ async Task<HttpResponse> ExecuteRequestAsync(RestRequest request, CancellationTo
         if (_disposed) {
             throw new ObjectDisposedException(nameof(RestClient));
         }
-
+        await OnBeforeSerialization(request);    
         request.ValidateParameters();
         var authenticator = request.Authenticator ?? Options.Authenticator;
         if (authenticator != null) await authenticator.Authenticate(this, request).ConfigureAwait(false);
@@ -107,8 +107,8 @@ async Task<HttpResponse> ExecuteRequestAsync(RestRequest request, CancellationTo
                 .AddCookieHeaders(url, Options.CookieContainer);
 
             message.AddHeaders(headers);
-
             if (request.OnBeforeRequest != null) await request.OnBeforeRequest(message).ConfigureAwait(false);
+            await OnBeforeRequest(message);
 
             var responseMessage = await HttpClient.SendAsync(message, request.CompletionOption, ct).ConfigureAwait(false);
 
@@ -121,6 +121,7 @@ async Task<HttpResponse> ExecuteRequestAsync(RestRequest request, CancellationTo
             }
 
             if (request.OnAfterRequest != null) await request.OnAfterRequest(responseMessage).ConfigureAwait(false);
+            await OnAfterRequest(responseMessage);
 
             return new HttpResponse(responseMessage, url, cookieContainer, null, timeoutCts.Token);
         }
@@ -129,6 +130,34 @@ async Task<HttpResponse> ExecuteRequestAsync(RestRequest request, CancellationTo
         }
     }
 
+    /// <summary>
+    /// Will be called before the Request becomes Serialized
+    /// </summary>
+    /// <param name="request">RestRequest before it will be serialized</param>
+    async Task OnBeforeSerialization(RestRequest request) {
+        foreach (var interceptor in Options.Interceptors) {
+            await interceptor.InterceptBeforeSerialization(request); //.ThrowExceptionIfAvailable();
+        }
+    }
+    /// <summary>
+    /// Will be called before the Request will be sent
+    /// </summary>
+    /// <param name="requestMessage">HttpRequestMessage ready to be sent</param>
+    async Task OnBeforeRequest(HttpRequestMessage requestMessage) {
+        foreach (var interceptor in Options.Interceptors) {
+            await interceptor.InterceptBeforeRequest(requestMessage);
+        }
+    }
+    /// <summary>
+    /// Will be called after the Response has been received from Server
+    /// </summary>
+    /// <param name="responseMessage">HttpResponseMessage as received from server</param>
+    async Task OnAfterRequest(HttpResponseMessage responseMessage) {
+        foreach (var interceptor in Options.Interceptors) {
+            await interceptor.InterceptAfterRequest(responseMessage);
+        }
+    }
+
     record HttpResponse(
         HttpResponseMessage? ResponseMessage,
         Uri                  Url,

src/RestSharp/RestSharp.csproj

@@ -39,4 +39,7 @@
     <ItemGroup>
         <ProjectReference Include="$(RepoRoot)\gen\SourceGenerator\SourceGenerator.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" />
     </ItemGroup>
+    <ItemGroup>
+      <PackageReference Include="System.Threading.Tasks" Version="4.3.0" />
+    </ItemGroup>
 </Project>

src/RestSharp/Serializers/RestSerializers.cs

@@ -39,6 +39,7 @@ internal RestResponse<T> Deserialize<T>(RestRequest request, RestResponse raw, R
 
         try {
             request.OnBeforeDeserialization?.Invoke(raw);
+            OnBeforeDeserialization(raw, options).ConfigureAwait(true);
             response.Data = DeserializeContent<T>(raw);
         }
         catch (Exception ex) {
@@ -53,6 +54,16 @@ internal RestResponse<T> Deserialize<T>(RestRequest request, RestResponse raw, R
 
         return response;
     }
+    /// <summary>
+    /// Will be called before the Data will be serialized
+    /// </summary>
+    /// <param name="raw">RestResponse with Data still in Content</param>
+    /// <param name="options">RestClient options but readonly</param>
+    async Task OnBeforeDeserialization(RestResponse raw, ReadOnlyRestClientOptions options) {
+        foreach (var interceptor in options.Interceptors) {
+            await interceptor.InterceptBeforeDeserialize(raw); //.ThrowExceptionIfAvailable();
+        }
+    }
 
     /// <summary>
     /// Deserialize the response content into the specified type

test/RestSharp.InteractiveTests/RestSharp.InteractiveTests.csproj

@@ -8,4 +8,7 @@
         <ProjectReference Include="$(RepoRoot)\src\RestSharp\RestSharp.csproj" />
         <ProjectReference Include="..\RestSharp.Tests.Shared\RestSharp.Tests.Shared.csproj" />
     </ItemGroup>
+    <ItemGroup>
+      <PackageReference Include="xunit.assert" Version="2.4.2" />
+    </ItemGroup>
 </Project>

test/RestSharp.Tests.Serializers.Xml/SampleClasses/twitter.cs

@@ -23,15 +23,15 @@ public class status {
     public string in_reply_to_screen_name { get; set; }
 
     // ignore contributors for now
-    public user user { get; set; }
+    public User user { get; set; }
 
     // ignore geo
     public long id { get; set; }
 
     public string text { get; set; }
 }
 
-public class user {
+public class User {
     public string url { get; set; }
 
     public string description { get; set; }
@@ -105,7 +105,7 @@ public class complexStatus {
     public string in_reply_to_screen_name { get; set; }
 
     // ignore contributors for now
-    [DeserializeAs(Name = "user.following")]
+    [DeserializeAs(Name = "User.following")]
     public bool follow { get; set; }
 
     // ignore geo