I am trying to write an integration test for a controller with a view. I do it as part of migration to .Net Core 3.1 from 2.2. There is a lot of configuration in ConfigureServices that we need to mock or disable in the tests, so, we derive from existing Startup class and override the parts needed.
Now, I can make it working in .Net Core 3.1 using WebApplicationFactory and overriding ConfigureWebHost. However, I rather hoped to not rewrite the existing class that derives from Startup.
I tried to use the approach from https://gunnarpeipman.com/aspnet-core-integration-test-startup/ where I specify the derived Startup for WebApplicationFactory and call UseSolutionRelativeContentRoot (which has UseContentRoot inside which I also tried). However, the views cannot be found. Part of the exception returned is:
System.InvalidOperationException: The view 'Index' was not found. The following locations were searched:
Features\Dummy\Index.cshtml
Features\Shared\Index.cshtml
\Features\Index\Dummy.cshtml
How could I fix the tests?
I have a "mock" project where I reproduce the issue.
public class Program
{
public static void Main(string[] args)
{
var host = BuildHost(args);
host.Run();
}
public static IHost BuildHost(string[] args) =>
Host.CreateDefaultBuilder(args)
.ConfigureWebHostDefaults(webBuilder => webBuilder
.UseStartup<Startup>())
.Build();
}
public class Startup
{
protected virtual void AddTestService(IServiceCollection services)
{
services.TryAddSingleton<IServiceToMock, ServiceToMock>();
}
public void ConfigureServices(IServiceCollection services)
{
AddTestService(services);
services.AddMvc()
.AddFeatureFolders();
}
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
app.UseRouting();
app.UseEndpoints(endpoints => endpoints.MapControllerRoute("default", "{controller=Home}/{action=Index}"));
}
}
public interface IServiceToMock
{
Task DoThing();
}
public class ServiceToMock : IServiceToMock
{
public async Task DoThing() =>
throw new Exception(await Task.FromResult("service exception"));
}
[Route("candidates/[controller]/[action]")]
public class DummyController : Controller
{
private readonly IServiceToMock serviceToMock;
public DummyController(IServiceToMock serviceToMock)
{
this.serviceToMock = serviceToMock;
}
[HttpGet]
public IActionResult Index()
{
return View();
}
[HttpGet]
public async Task<bool> IsExternal(string email)
{
await serviceToMock.DoThing();
return await Task.FromResult(!string.IsNullOrWhiteSpace(email));
}
}
Index.cshtml (goes in the same folder as the controller)
@{
ViewData["Title"] = "Title";
}
<p>Hello.</p>
csproj:
<Project Sdk="Microsoft.NET.Sdk.Web">
<PropertyGroup>
<TargetFramework>netcoreapp3.1</TargetFramework>
</PropertyGroup>
<ItemGroup>
<PackageReference Include="OdeToCode.AddFeatureFolders" Version="2.0.3" />
</ItemGroup>
</Project>
The test part:
public class TestServerFixture : TestServerFixtureBase<Startup, TestStartup>
{
}
public class TestServerFixtureBase<TSUTStartus, TTestStartup> : WebApplicationFactory<TTestStartup>
where TTestStartup : class where TSUTStartus : class
{
private readonly Lazy<HttpClient> m_AuthClient;
public TestServerFixtureBase()
{
m_AuthClient = new Lazy<HttpClient>(() => CreateAuthClient());
}
protected override IWebHostBuilder CreateWebHostBuilder()
{
return WebHost.CreateDefaultBuilder()
.UseStartup<TTestStartup>();
}
public HttpClient AuthClient => m_AuthClient.Value;
protected virtual HttpClient CreateAuthClient() => WithWebHostBuilder(builder =>
{
builder.UseSolutionRelativeContentRoot("NetCore31IntegrationTests3");
builder.ConfigureTestServices(services =>
{
services.AddMvc().AddApplicationPart(typeof(TSUTStartus).Assembly);
});
}).CreateClient();
}
public class TestStartup : Startup
{
protected override void AddTestService(IServiceCollection services)
{
services.AddSingleton<IServiceToMock, TestServiceToMock>();
}
}
public class TestServiceToMock : IServiceToMock
{
public async Task DoThing() => await Task.CompletedTask;
}
public class HomeControllerTests : IClassFixture<TestServerFixture>
{
private readonly TestServerFixture _factory;
public HomeControllerTests(TestServerFixture factory)
{
_factory = factory;
}
[Theory]
[InlineData("/candidates/dummy/IsExternal?email=aaa")]
[InlineData("/candidates/dummy/index")]
[InlineData("candidates/dummy/index")]
public async Task Get_EndpointsReturnSuccessAndCorrectContentType(string url)
{
// Arrange
var client = _factory.AuthClient;
// Act
var response = await client.GetAsync(url);
// Assert
response.EnsureSuccessStatusCode();
}
}
The working fix I am trying to avoid:
public class TestServerFixtureBase<TSUTStartus, TTestStartup> : WebApplicationFactory<TSUTStartus>
where TTestStartup : class where TSUTStartus : class
{
private readonly Lazy<HttpClient> m_AuthClient;
public TestServerFixtureBase()
{
m_AuthClient = new Lazy<HttpClient>(() => CreateAuthClient());
}
protected override void ConfigureWebHost(IWebHostBuilder builder)
{
builder.ConfigureServices(services =>
{
var descriptor = services.SingleOrDefault(
d => d.ServiceType ==
typeof(IServiceToMock));
if (descriptor != null)
services.Remove(descriptor);
services.AddSingleton<IServiceToMock, TestServiceToMock>();
});
}
protected override IWebHostBuilder CreateWebHostBuilder()
{
return WebHost.CreateDefaultBuilder()
.UseStartup<TSUTStartus>();
}
public HttpClient AuthClient => m_AuthClient.Value;
protected virtual HttpClient CreateAuthClient() => WithWebHostBuilder(builder => { }).CreateClient();
}
