fix: HttpClient instance per request

src/Crowdin.Api/CrowdinApiClient.cs

@@ -1,4 +1,4 @@
-
+
 using System;
 using System.Collections.Generic;
 using System.IO;
@@ -98,7 +98,7 @@ public class CrowdinApiClient : ICrowdinApiClient
 
         private readonly string _baseUrl;
         private readonly string _accessToken;
-        private readonly HttpClient _httpClient;
+        private readonly Func<HttpClient> _httpClientFactory;
         private readonly IRetryService? _retryService;
 
         private static readonly MediaTypeHeaderValue DefaultContentType = MediaTypeHeaderValue.Parse("application/json");
@@ -124,18 +124,16 @@ public class CrowdinApiClient : ICrowdinApiClient
 
         public CrowdinApiClient(
             CrowdinCredentials credentials,
-            HttpClient? httpClient = null,
+            Func<HttpClient>? httpClientFactory = null,
             IJsonParser? jsonParser = null,
             IRetryService? retryService = null)
         {
-            _httpClient = httpClient ?? new HttpClient();
+            _httpClientFactory = httpClientFactory ?? (() => new HttpClient());
             DefaultJsonParser = jsonParser ?? new JsonParser(DefaultJsonSerializerOptions);
             _retryService = retryService;
 
             _accessToken = credentials.AccessToken;
-            _httpClient.DefaultRequestHeaders.Authorization =
-                new AuthenticationHeaderValue("Bearer", credentials.AccessToken);
-
+
             // pass base url full
             if (!string.IsNullOrWhiteSpace(credentials.BaseUrl))
             {
@@ -308,14 +306,23 @@ public Task<CrowdinApiResult> UploadFile(string subUrl, string filename, Stream
             return outResultList.ToArray();
         }
 
+        private HttpClient GetHttpClientInstance()
+        {
+            var httpClient = _httpClientFactory();
+            httpClient.DefaultRequestHeaders.Authorization =
+                new AuthenticationHeaderValue("Bearer", _accessToken);
+
+            return httpClient;
+        }
+
         private async Task<CrowdinApiResult> SendRequest(HttpRequestMessage request)
         {
             var result = new CrowdinApiResult();
-            
+
             HttpResponseMessage response =
                 _retryService != null
-                ? await _retryService.ExecuteRequestAsync(() => _httpClient.SendAsync(request))
-                : await _httpClient.SendAsync(request);
+                ? await _retryService.ExecuteRequestAsync(() => GetHttpClientInstance().SendAsync(request))
+                : await GetHttpClientInstance().SendAsync(request);
 
             await CheckDefaultPreconditionsAndErrors(response);
             result.StatusCode = response.StatusCode;