NewsListFragmentTest.kt

@ExperimentalCoroutinesApi
@UninstallModules(
    UrlProviderModule::class,
    CacheControlModule::class
)
@HiltAndroidTest
@RunWith(AndroidJUnit4::class)
class BaseFragmentTest {

    @get:Rule val hiltRule = HiltAndroidRule(this)

    val navController = TestNavHostController(ApplicationProvider.getApplicationContext())

    protected lateinit var mockWebServer: MockWebServer

    @Inject lateinit var okHttp: OkHttpClient

    @Before
    open fun setUp() {
        hiltRule.inject()
        mockWebServer = MockWebServer()
        mockWebServer.dispatcher = MockServerDispatcher().RequestDispatcher()
        mockWebServer.start(8080)
        IdlingRegistry.getInstance().register(OkHttp3IdlingResource.create("okhttp", okHttp))
    }

    @After
    open fun tearDown() {
        mockWebServer.shutdown()
    }
  
    @Test
    fun givenArticleIsClickedThenNavigateToDetailsScreen() {
        //Launch fragment
        launchNewsListFragment()

        //Click on first article
        onView(withId(R.id.recyclerView)).perform(actionOnItemAtPosition<RecyclerView.ViewHolder>(1, click()))

        //Check that it navigates to Detail screen
        assertThat(navController.currentDestination?.id).isEqualTo(R.id.newsDetailFragment)
    }
  
    private fun launchNewsListFragment() {
          launchFragmentInHiltContainer<NewsListFragment> {
              navController.setGraph(R.navigation.main_nav_graph)
              navController.setCurrentDestination(R.id.newsListFragment)
              this.viewLifecycleOwnerLiveData.observeForever { viewLifecycleOwner ->
                  if (viewLifecycleOwner != null) {
                      // The fragment’s view has just been created
                      Navigation.setViewNavController(this.requireView(), navController)
                  }
              }
          }
      }

      @Module
      @InstallIn(ApplicationComponent::class)
      class FakeBaseUrlModule {

          @Provides
          @Singleton
          fun provideUrl(): String = "http://localhost:8080/"
      }
}

inline fun <reified T : Fragment> launchFragmentInHiltContainer(
    fragmentArgs: Bundle? = null,
    @StyleRes themeResId: Int = R.style.Theme,
    fragmentFactory: FragmentFactory? = null,
    crossinline action: Fragment.() -> Unit = {}
) {
    val startActivityIntent = Intent.makeMainActivity(
        ComponentName(
            ApplicationProvider.getApplicationContext(),
            HiltTestActivity::class.java
        )
    ).putExtra(EmptyFragmentActivity.THEME_EXTRAS_BUNDLE_KEY, themeResId)

    ActivityScenario.launch<HiltTestActivity>(startActivityIntent).onActivity { activity ->
        fragmentFactory?.let {
            activity.supportFragmentManager.fragmentFactory = it
        }
        val fragment: Fragment = activity.supportFragmentManager.fragmentFactory.instantiate(
            Preconditions.checkNotNull(T::class.java.classLoader),
            T::class.java.name
        )

        fragment.arguments = fragmentArgs
        activity.supportFragmentManager
            .beginTransaction()
            .add(android.R.id.content, fragment, "")
            .commitNow()

        fragment.action()
    }
}