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Testing with Hilt

The libraries below assume you have knowledge about how to write instrumented tests with Hilt.

The official guide is a good starting point.

Setup

Add the following dependency:

debugImplementation "com.rubensousa.carioca:hilt-manifest:1.0.0"

Then pick one or both of these:

androidTestImplementation "com.rubensousa.carioca:hilt-fragment:1.0.0"
androidTestImplementation "com.rubensousa.carioca:hilt-compose:1.0.0"

If you don't have a default HiltTestRunner, you can also use this one, as recommended by the official docs.

android {
    defaultConfig {
        testInstrumentationRunner = "com.rubensousa.carioca.hilt.runner.HiltTestRunner"
    }
}

dependencies {
    androidTestImplementation "com.rubensousa.carioca:hilt-runner:1.0.0"
}

Fragment

Before continuing, please check the official guide for testing fragments.

com.rubensousa.carioca:hilt-fragment contains HiltFragmentScenario, similar to FragmentScenario from the fragment-testing library.

The API is similar to FragmentScenario: launchHiltFragment

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@HiltAndroidTest
class ExampleTest {

    @get:Rule
    val hiltRule = HiltAndroidRule(this)

    @Inject
    lateinit var injectedDependency: TestDependency

    @Before
    fun setup() {
        hiltRule.inject()
    }

    @Test
    fun testFragmentReceivesDependencyFromHilt() {
        // given
        val scenario = launchHiltFragment<TestFragment>()

        // when
        var fragmentDependency: TestDependency? = null
        scenario.onFragment { fragment ->
            fragmentDependency = fragment.getInjectedDependency()
        }

        // then
        assertThat(fragmentDependency).isSameInstanceAs(injectedDependency)
    }

}

Compose

Before continuing, please check the official guide for testing Compose layouts.

com.rubensousa.carioca:hilt-compose contains createHiltComposeRule, which is similar to createAndroidComposeRule:

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@HiltAndroidTest
class HiltComposeRuleTest {

    @get:Rule
    val hiltRule = HiltAndroidRule(this)

    @get:Rule(order = 1)
    val composeTestRule = createHiltComposeRule()

    @Inject
    lateinit var injectedDependency: TestDependency

    @Before
    fun setup() {
        hiltRule.inject()
    }

    @Test
    fun testComposableReceivesDependencyFromHilt() {
        // given
        var dependencyFromViewModel: Dependency? = null
        composeTestRule.setContent {
            val viewModel = viewModel<TestViewModel>()
            dependencyFromViewModel = viewModel.dependency
        }

        // when
        composeTestRule.waitForIdle()

        // then
        assertThat(dependencyFromViewModel).isSameInstanceAs(injectedDependency)

    }

    @HiltViewModel
    class TestViewModel @Inject constructor(
        val dependency: TestDependency,
    ) : ViewModel()
}