TestRender.DisposeComponents() does not correctly dispose components that implement IAsyncDisposable

[allderidge]

TestRender.DisposeComponents() does not correctly dispose components that implement IAsyncDisposable

[linkdotnet]

Hey @allderidge,

this is unfortunately a limitation we can't overcome. The Blazor renderer doesn't await DisposeAsync, therefore DisposeComponents isn't blocking until DisposeAsync is done.

Therefore you have to find other ways of telling whether or not DisposeAsync is done (in the worst: Task.Delay(10);).

[egil]

Yeah, unfortunately, we do not currently have a hook into the Blazor renderere that allows us to await async disposal, as @linkdotnet says.

That said, you can probably test the logic you need to test in isolation by calling DisposeAsync yourself:

@inherits TestContextWrapper

@code
{
    [Test]
    public async Task DisposeAsync_Is_Called_When_Disposing_Components()
    {
        TestContext = new Bunit.TestContext();
        TestContext.JSInterop.Mode = JSRuntimeMode.Loose;
        var sut = Render(@<Bug />);
        var instance = sut.FindComponent<Bug>().Instance;

        await instance.DisposeAsync();

        // DisposeComponents();
        Assert.IsTrue(instance.WasDisposed);
    }
}

[allderidge]

Thanks, it does looks like there's very little that can be done other than going into a loop which waits and tests for the outcome until some timeout.

I was thinking that these issues could be solved by implementing your own SynchronizationContext used to wait for all spawned tasks to be processed.

[egil]

We are actively investigating options like that for V2 of bUnit, but it will be hard to do it for V1 (breaking changes etc.

[linkdotnet]

Done by #1415

[linkdotnet]

@allderidge

We implemented the feature on our upcoming v2 of bUnit. Currently, this version is in preview, but if you feel a bit more adventurous, you can try out the latest preview: https://www.nuget.org/packages/bunit/2.0.24-preview

As it is a major version, there are breaking changes. We have a rudimentary Migration Guide: https://github.com/bUnit-dev/bUnit/blob/v2/MIGRATION.md

Every feedback helps us.

Your test from above can now be properly done via: await DisposeComponentsAsync();