Infrastructure for E2E tests where the app makes requests to an API server

samples/StandaloneApp/Pages/FetchData.cshtml

@@ -10,6 +10,6 @@
 
     protected override async Task OnInitAsync()
     {
-        responseText = await Http.GetStringAsync("http://example.com/");
+        responseText = await Http.GetStringAsync("/");
     }
 }

test/Microsoft.AspNetCore.Blazor.E2ETest/Microsoft.AspNetCore.Blazor.E2ETest.csproj

@@ -23,6 +23,7 @@
     <ProjectReference Include="..\..\samples\StandaloneApp\StandaloneApp.csproj" />
     <ProjectReference Include="..\..\src\Microsoft.AspNetCore.Blazor.DevHost\Microsoft.AspNetCore.Blazor.DevHost.csproj" />
     <ProjectReference Include="..\testapps\BasicTestApp\BasicTestApp.csproj" />
+    <ProjectReference Include="..\testapps\TestServer\TestServer.csproj" />
   </ItemGroup>
 
 </Project>

test/Microsoft.AspNetCore.Blazor.E2ETest/Tests/HttpClientTest.cs

@@ -0,0 +1,40 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using Microsoft.AspNetCore.Blazor.E2ETest.Infrastructure;
+using Microsoft.AspNetCore.Blazor.E2ETest.Infrastructure.ServerFixtures;
+using System;
+using System.Net.Http;
+using System.Threading.Tasks;
+using Xunit;
+
+namespace Microsoft.AspNetCore.Blazor.E2ETest.Tests
+{
+    public class HttpClientTest : BasicTestAppTestBase, IClassFixture<AspNetSiteServerFixture>
+    {
+        readonly ServerFixture _apiServerFixture;
+
+        public HttpClientTest(
+            BrowserFixture browserFixture,
+            DevHostServerFixture<BasicTestApp.Program> devHostServerFixture,
+            AspNetSiteServerFixture apiServerFixture)
+            : base(browserFixture, devHostServerFixture)
+        {
+            apiServerFixture.BuildWebHostMethod = TestServer.Program.BuildWebHost;
+            _apiServerFixture = apiServerFixture;
+
+            //Navigate(ServerPathBase, noReload: true);
+        }
+
+        [Fact]
+        public async Task SanityCheck_ApiServerIsRunning()
+        {
+            // Just so we can be sure that the other tests are even relevant
+            // Note that the HttpClient we're instantiating here is *not* the
+            // one under test. This is not related to Blazor in any way.
+            var httpClient = new HttpClient { BaseAddress = _apiServerFixture.RootUri };
+            var responseText = await httpClient.GetStringAsync("/api/greeting/sayhello");
+            Assert.Equal("Hello", responseText);
+        }
+    }
+}

test/testapps/TestServer/Controllers/GreetingController.cs

@@ -0,0 +1,11 @@
+using Microsoft.AspNetCore.Mvc;
+
+namespace TestServer.Controllers
+{
+    [Route("api/[controller]/[action]")]
+    public class GreetingController : Controller
+    {
+        [HttpGet]
+        public string SayHello() => "Hello";
+    }
+}

test/testapps/TestServer/Program.cs

@@ -1,12 +1,6 @@
-using System;
+using Microsoft.AspNetCore;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Threading.Tasks;
-using Microsoft.AspNetCore;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.Extensions.Configuration;
-using Microsoft.Extensions.Logging;
 
 namespace TestServer
 {
@@ -19,6 +13,9 @@ namespace TestServer
 
         public static IWebHost BuildWebHost(string[] args) =>
             WebHost.CreateDefaultBuilder(args)
+                .UseConfiguration(new ConfigurationBuilder()
+                        .AddCommandLine(args)
+                        .Build())
                 .UseStartup<Startup>()
                 .Build();
     }

test/testapps/TestServer/Startup.cs

@@ -1,13 +1,7 @@
-using System;
+using Microsoft.AspNetCore.Builder;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
-using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.Logging;
-using Microsoft.Extensions.Options;
 
 namespace TestServer
 {