LightInject fallback service provider

[dady8889]

Hello,

I am trying to test my project that uses LightInject using MSTests with bUnit (1.1.5).
I have created the wrapper class for tests like this:

public abstract class BUnitTestContext : TestContextWrapper
    {
        [TestInitialize]
        public void Setup()
        {
            TestContext = new Bunit.TestContext();

            var container = new ServiceContainer(ContainerOptions.Default.WithMicrosoftSettings());
            container.RegisterFrom<TestModule>();
            container.BeginScope();
            var provider = container.CreateServiceProvider(new ServiceCollection());
            TestContext.Services.AddFallbackServiceProvider(provider);
        }

        [TestCleanup]
        public void TearDown()
        {
            TestContext?.Dispose();
        }
    }

The test case looks like this:

[TestClass]
    public class AddNewOrderUnitTest : BUnitTestContext
    {
        [TestMethod]
        public void Test1()
        {
            var orderService = TestContext.Services.GetService<DOS_BL.Services.OrderService>(); // this returns the OrderService as it should
            var cut = RenderComponent<DOS_PL.Pages.Orders.Add>(); // this throws error

            var inputs = cut.FindAll("input");
        }
    }

As you can see, the RenderComponent throws

'Cannot provide a value for property 'OrderService' on type 'DOS_PL.Pages.Orders.Add'. There is no registered service of type 'DOS_BL.Services.OrderService'.'

I tried adding the service using .AddScoped on the TestContext and that worked. But I really don't want to copy all the services manually because I am also using a mapper and it would be a lot to copy.

I really don't understand why it throws in the RenderComponent when I can get the service manually in the test.
(the LightInject documentation is not very good for this kind of thing, but still, it kinda works.)
Is there something I am doing wrong or something that would help to investigate the problem?

Thanks.

[egil]

Hi @dady8889

I do not know how LightInject works, but the fallback service provider is being called when the primary cannot resolve the request, i.e.:

public object? GetService(Type serviceType)
	=> GetServiceInternal(serviceType);

private object? GetServiceInternal(Type serviceType)
{
	if (serviceProvider is null)
		serviceProvider = serviceCollection.BuildServiceProvider();

	var result = serviceProvider.GetService(serviceType);

	if (result is null && fallbackServiceProvider is not null)
		result = fallbackServiceProvider.GetService(serviceType);

	return result;
}

So I am not sure why your code is not working. Please create a minimal reproduction of the issue, but it in a repo or zip file, so I can download and try it locally to figure to figure out what is going on.

[dady8889]

I prepared a sample project. The test file is TestProject -> UnitTest1.cs
bUnitLightInjectBug.zip

Thank you for checking the issue.
If you won't find anything I will try to ask in the LightInject github.

[egil]

Hey again, can confirm this is a bug. Not sure why yet. Ill get back to you on this.

[egil]

There is a fix for this on its way to GitHub Package Repository, and it will also be available in the next 1.2 release of bUnit. To get the preview release of v1.2, see this post for instructions: #209

Thanks again for reporting this issue.