kelmer44/testFixturesTest

Hilt with Test Fixtures

The project demonstrates Hilt not processing annotated resources in newly released (still experimental) Android module's testFixtures.

This is a very simple Compose app that displays a list of random people. I've created an instrumentation test for this screen in the consuminglib module.

The androidlib module declares a PeopleServiceinterface and a default implementation, which is bound in PeopleModule.

Within the androidlib module I've put a FakePeopleService (which offers deterministic results, ideal for tests), and also my FakePeopleModule where I use @TestInstallIn to replace the module declared in the main source set.

@Module
@TestInstallIn(
    components = [SingletonComponent::class],
    replaces = [PeopleModule::class]
)
interface FakePeopleModule {
    @Binds
    fun bindsPeopleService(
        defaultPeopleService: FakePeopleService
    ): PeopleService
}

When running my test from consuminglib the binding is never replaced, and no generated code is produced for testFixtures.

You'll find that in PeopleScreenTest some lines are commented out, those do work in replacing the binding with the fake implementation, which goes to prove that testFixtures does actually get properly imported.