Add test that uses localization

test/FunctionalTests/Client/UnaryTests.cs

@@ -68,6 +68,35 @@ Task<HelloReply> UnaryThrowError(HelloRequest request, ServerCallContext context
         StringAssert.StartsWith("Failed to deserialize response message.", call.GetStatus().Detail);
     }
 
+    [TestCase("fr", "fr")]
+    [TestCase(null, "en-US")]
+    public async Task Unary_SetAcceptLanguage_ServerCultureChanged(string clientAcceptLanguage, string expectedServerCulture)
+    {
+        string? serverCulture = null;
+        Task<HelloReply> UnaryThrowError(HelloRequest request, ServerCallContext context)
+        {
+            serverCulture = Thread.CurrentThread.CurrentCulture.Name;
+            return Task.FromResult(new HelloReply { Message = serverCulture });
+        }
+
+        // Arrange
+        var method = Fixture.DynamicGrpc.AddUnaryMethod<HelloRequest, HelloReply>(UnaryThrowError);
+        var channel = CreateChannel();
+        var client = TestClientFactory.Create(channel, method);
+        var metadata = new Metadata();
+        if (clientAcceptLanguage != null)
+        {
+            metadata.Add("accept-language", clientAcceptLanguage);
+        }
+
+        // Act
+        var call = client.UnaryCall(new HelloRequest(), new CallOptions(headers: metadata));
+        await call.ResponseAsync.DefaultTimeout();
+
+        // Assert
+        Assert.AreEqual(expectedServerCulture, serverCulture);
+    }
+
 #if NET5_0_OR_GREATER
     [Test]
     public async Task MaxConcurrentStreams_StartConcurrently_AdditionalConnectionsCreated()

testassets/FunctionalTestsWebsite/Startup.cs

@@ -17,6 +17,7 @@
 #endregion
 
 using System.Diagnostics;
+using System.Globalization;
 using System.IdentityModel.Tokens.Jwt;
 using System.Security.Claims;
 using FunctionalTestsWebsite.Infrastructure;
@@ -26,6 +27,7 @@
 using Grpc.HealthCheck;
 using Grpc.Tests.Shared;
 using Microsoft.AspNetCore.Authentication.JwtBearer;
+using Microsoft.AspNetCore.Localization;
 using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.IdentityModel.Tokens;
 
@@ -123,6 +125,20 @@ static Uri GetCurrentAddress(IServiceProvider serviceProvider)
 
             return new Uri($"{context.Request.Scheme}://{context.Request.Host.Value}");
         }
+
+        services.Configure<RequestLocalizationOptions>(options =>
+        {
+            const string enUSCulture = "en-US";
+            var supportedCultures = new[]
+            {
+                new CultureInfo(enUSCulture),
+                new CultureInfo("fr")
+            };
+
+            options.DefaultRequestCulture = new RequestCulture(culture: enUSCulture, uiCulture: enUSCulture);
+            options.SupportedCultures = supportedCultures;
+            options.SupportedUICultures = supportedCultures;
+        });
     }
 
     // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
@@ -168,9 +184,10 @@ public void Configure(IApplicationBuilder app)
                 await next();
             }
         });
-
         app.UseRouting();
 
+        app.UseRequestLocalization();
+
         app.UseAuthorization();
         app.UseGrpcWeb(new GrpcWebOptions { DefaultEnabled = true });
         app.UseCors();