Make use of "x-ratelimit-reset" HTTP response header when rate limit is exceeded in tests

Author: sierpinskid

Assets/Plugins/StreamChat/Core/LowLevelClient/API/Internal/InternalApiClientBase.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using StreamChat.Core.Exceptions;
@@ -161,11 +162,8 @@ private async Task<TResponse> HttpRequest<TResponse>(HttpMethodType httpMethod,
 #if STREAM_TESTS_ENABLED
                 if (apiError.StatusCode == StreamApiException.RateLimitErrorHttpStatusCode && attempt < 50)
                 {
-                    var delaySeconds = 61 + attempt * 10;
-                    _logs.Warning($"API CLIENT, TESTS MODE, Rate Limit API Error - Wait for {delaySeconds} seconds");
-                    await Task.Delay(delaySeconds * 1000);
-                    return await HttpRequest<TResponse>(httpMethod, endpoint,
-                        requestBody, queryParameters, ++attempt);
+                    return await HandleRateLimit<TResponse>(httpMethod, endpoint, requestBody, queryParameters, attempt,
+                        httpResponse);
                 }
 #endif
 
@@ -296,5 +294,42 @@ private void LogRestCall(Uri uri, string endpoint, HttpMethodType httpMethod, st
 
             _logs.Info(_sb.ToString());
         }
+
+        private async Task<TResponse> HandleRateLimit<TResponse>(HttpMethodType httpMethod, string endpoint,
+            object requestBody, QueryParameters queryParameters, int attempt, HttpResponse httpResponse)
+        {
+            if (attempt >= 50)
+            {
+                throw new StreamApiException(new APIErrorInternalDTO
+                    { Code = StreamApiException.RateLimitErrorHttpStatusCode });
+            }
+
+            var delaySeconds = GetBackoffDelay(attempt, httpResponse, out var resetHeaderTimestamp);
+            _logs.Warning($"API CLIENT, TESTS MODE, Rate Limit API Error - Wait for {delaySeconds} seconds. Timestamp reset header: {resetHeaderTimestamp}");
+            await Task.Delay(delaySeconds * 1000);
+            return await HttpRequest<TResponse>(httpMethod, endpoint, requestBody, queryParameters, ++attempt);
+        }
+
+        private int GetBackoffDelay(int attempt, HttpResponse httpResponse, out int resetHeaderTimestamp)
+        {
+            resetHeaderTimestamp = -1;
+            if (httpResponse.TryGetHeader("x-ratelimit-reset", out var values))
+            {
+                var resetTimestamp = values.FirstOrDefault();
+
+                if (int.TryParse(resetTimestamp, out var rateLimitTimestamp))
+                {
+                    resetHeaderTimestamp = rateLimitTimestamp;
+                    var now = (int)new DateTimeOffset(DateTime.UtcNow).ToUnixTimeSeconds();
+                    var secondsLeft = rateLimitTimestamp - now;
+                    if (secondsLeft > 0)
+                    {
+                        return secondsLeft;
+                    }
+                }
+            }
+
+            return 61 + attempt * 10;
+        }
     }
 }

Assets/Plugins/StreamChat/Libs/Http/HttpResponse.cs

@@ -1,4 +1,5 @@
-using System.Net.Http;
+using System.Collections.Generic;
+using System.Net.Http;
 using System.Threading.Tasks;
 using StreamChat.Libs.Utils;
 using UnityEngine.Networking;
@@ -14,24 +15,56 @@ public readonly struct HttpResponse
         public int StatusCode { get; }
         public string Result { get; }
 
+        public bool TryGetHeader(string key, out IEnumerable<string> values)
+        {
+            values = null;
+
+            if (_httpResponseMessage != null)
+            {
+                return _httpResponseMessage.Headers.TryGetValues(key, out values);
+            }
+
+            if (_unityWebRequest != null)
+            {
+                var value = _unityWebRequest.GetResponseHeader(key);
+                if (value != null)
+                {
+                    values = new[] { value };
+                }
+
+                return value != null;
+            }
+
+            return false;
+        }
+
         public static async Task<HttpResponse> CreateFromHttpResponseMessageAsync(
             HttpResponseMessage httpResponseMessage)
         {
             var result = await httpResponseMessage.Content.ReadAsStringAsync();
-            return new HttpResponse(httpResponseMessage.IsSuccessStatusCode, (int)httpResponseMessage.StatusCode, result);
+            return new HttpResponse(httpResponseMessage.IsSuccessStatusCode, (int)httpResponseMessage.StatusCode,
+                result, httpResponseMessage, null);
         }
 
         public static HttpResponse CreateFromUnityWebRequest(UnityWebRequest unityWebRequest)
         {
             var result = unityWebRequest.downloadHandler?.text ?? string.Empty;
-            return new HttpResponse(unityWebRequest.IsRequestSuccessful(), (int)unityWebRequest.responseCode, result);
+            return new HttpResponse(unityWebRequest.IsRequestSuccessful(), (int)unityWebRequest.responseCode, result,
+                null,
+                unityWebRequest);
         }
 
-        public HttpResponse(bool isSuccessStatusCode, int statusCode, string result)
+        public HttpResponse(bool isSuccessStatusCode, int statusCode, string result,
+            HttpResponseMessage httpResponseMessage, UnityWebRequest unityRequest)
         {
             IsSuccessStatusCode = isSuccessStatusCode;
             StatusCode = statusCode;
             Result = result;
+            _httpResponseMessage = httpResponseMessage;
+            _unityWebRequest = unityRequest;
         }
+
+        private readonly HttpResponseMessage _httpResponseMessage;
+        private readonly UnityWebRequest _unityWebRequest;
     }
 }

Assets/Plugins/StreamChat/Tests/LowLevelClient/Api/MessageApi.cs

@@ -59,7 +59,7 @@ public void when_client_post_request_expect_valid_uri_and_request_body_in_http_c
         {
             _lowLevelClient.Connect();
 
-            var response = new HttpResponse(true, 200, "{\"reaction\": {\"type\": \"like\"}}");
+            var response = new HttpResponse(true, 200, "{\"reaction\": {\"type\": \"like\"}}", null, null);
 
             _mockHttpClient.SendHttpRequestAsync(Arg.Is(HttpMethodType.Post),Arg.Any<Uri>(), Arg.Any<object>())
                 .Returns(response);
@@ -77,7 +77,7 @@ public void when_client_delete_request_expect_valid_uri_in_http_client(EndpointT
         {
             _lowLevelClient.Connect();
 
-            var response = new HttpResponse(true, 200, "{\"reaction\": {\"type\": \"like\"}}");
+            var response = new HttpResponse(true, 200, "{\"reaction\": {\"type\": \"like\"}}", null, null);
 
             _mockHttpClient.SendHttpRequestAsync(Arg.Is(HttpMethodType.Post),Arg.Any<Uri>(), Arg.Any<HttpContent>())
                 .Returns(response);