.net core 3.0, issue with IClassFixture, “unresolved constructor arguments: ITestOutputHelper output”

[ranouf]

I made a repo for the issue I have with Integration testing upgrading to .net core 3.0 :
https://github.com/ranouf/TestingWithDotNetCore3_0

When I launch the test, I have this issue:
Message:

System.AggregateException : One or more errors occurred. (Class fixture type 'MyIntegrationTests.TestServerFixture' had one or more
unresolved constructor arguments: ITestOutputHelper output) (The
following constructor parameters did not have matching fixture data:
TestServerFixture testServerFixture)
---- Class fixture type 'MyIntegrationTests.TestServerFixture' had one or more unresolved constructor arguments: ITestOutputHelper output
---- The following constructor parameters did not have matching fixture data: TestServerFixture testServerFixture Stack Trace:
----- Inner Stack Trace #1 (Xunit.Sdk.TestClassException) -----
----- Inner Stack Trace #2 (Xunit.Sdk.TestClassException) -----

Here is the constructor:

public class WeatherForecastController_Tests : IClassFixture<TestServerFixture>
{
    public WeatherForecastController_Tests(TestServerFixture testServerFixture, ITestOutputHelper output)
    {
        Client = testServerFixture.Client;
        Output = output;
    }

TestStartup:

public class TestStartup : Startup
{
    public TestStartup(IConfiguration configuration)
        : base(configuration)
    {
        
    }

    public override void SetUpDataBase(IServiceCollection services)
    {
        // here is where I use the InMemoryDatabase 
    }
}

TestServerFixture:

public class TestServerFixture : WebApplicationFactory<TestStartup>
{
    private IHost _host;
    public HttpClient Client { get; }
    public ITestOutputHelper Output { get; }

    public TestServerFixture(ITestOutputHelper output)
    {
        Output = output;
        Client = Server.CreateClient();
    }

    // never called but this is where i was previously building up the server
    //
    protected override TestServer CreateServer(IWebHostBuilder builder)
    {
        return base.CreateServer(builder);
    }

    protected override IHost CreateHost(IHostBuilder builder)
    {
        _host = builder.Build();

        using (var scope = _host.Services.CreateScope())
        {
            var services = scope.ServiceProvider;
            InitializeDataBase(services, Output);
        }

        _host.Start();
        return _host;
    }

    protected override IHostBuilder CreateHostBuilder() =>
        Host.CreateDefaultBuilder()
            .ConfigureLogging((hostingContext, builder) =>
            {
                builder.Services.AddSingleton<ILoggerProvider>(new XunitLoggerProvider(Output));
            })
            .ConfigureWebHostDefaults(webBuilder =>
            {
                webBuilder.UseTestServer();
            });

    protected override void ConfigureWebHost(IWebHostBuilder builder)
    {
        builder.UseStartup<TestStartup>();
    }

    private void InitializeDataBase(IServiceProvider services, ITestOutputHelper output)
    {
        try
        {
            output.WriteLine("Starting the database initialization.");
            //here is where is feed the Test DB
            output.WriteLine("The database initialization has been done.");
        }
        catch (Exception ex)
        {
            output.WriteLine("An error occurred while initialization the database.");
            Console.WriteLine(ex.Message);
        }
    }
}

So clearly, the Iod for TestServerFixture testServerFixture and ITestOutputHelper output doesnt work. How to make it work?

Note: This question is also on StackOverflow

[ranouf]

I was thinking that maybe ITestOutputHelper was a service injected by Xunit with "UseTestServer". So I tried in TestServerFixture to do this:

    public TestServerFixture()
    {
        Output = Services.GetRequiredService<ITestOutputHelper>(); ;
        Client = Server.CreateClient();
        InitializeDataBase();
    }

But I got the error:

System.InvalidOperationException: 'No service for type 'Xunit.Abstractions.ITestOutputHelper' has been registered.'

[ranouf]

Hi,

I found a solution available here: https://stackoverflow.com/a/59222453/6123422

:)