ImageLoader Test case

@RunWith(AndroidJUnit4::class)
class UrlImageParserTest {
  @Inject
  lateinit var mockImageLoader: ImageLoader // Inject the mock ImageLoader provided below.

  private lateinit var launchedActivity: Activity

  @get:Rule
  var activityTestRule: ActivityTestRule<UrlImageParserTestActivity> = ActivityTestRule(
    UrlImageParserTestActivity::class.java, /* initialTouchMode= */ true, /* launchActivity= */ false
  )

  @Before
  fun setUp() {
    mockImageLoader = Mockito.mock(ImageLoader::class.java)
    Intents.init()
    val intent = Intent(Intent.ACTION_PICK)
    launchedActivity = activityTestRule.launchActivity(intent)
  }

  // Prepares the ImageLoader for receiving the specified bitmap for the given URL.
  private fun prepareImageLoaderForResponse(expectedUrl: String, bitmap: Bitmap) {
    val imageView = activityTestRule.activity.findViewById(R.id.test_url_parser_image_view) as ImageView
    doAnswer { invocation ->
      val customTarget: CustomTarget<Bitmap> = invocation.getArgument(1)
      customTarget.onResourceReady(bitmap, /* transition= */ null)
      imageView.setImageBitmap(bitmap)
    }.`when`(mockImageLoader).load(expectedUrl, any())
  }
  
  @Test
  fun testImageLoader_returnSuccess() {
    var bitmap: Bitmap? = null
    var drawable: Drawable? = null
    val target = object : CustomTarget<Bitmap>() {
      override fun onLoadCleared(placeholder: Drawable?) {
        TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
      }
      override fun onResourceReady(resource: Bitmap, transition: Transition<in Bitmap>?) {
        drawable = BitmapDrawable(activityTestRule.activity.getResources(), resource);
        bitmap = resource

      }
    }
    mockImageLoader.load(OK_IMAGE_URL,target)
    prepareImageLoaderForResponse(OK_IMAGE_URL, bitmap!!)
  }
  @After
  fun tearDown() {
    Intents.release()
  }

  @Module
  class TestModule {
    @Provides
    fun provideImageLoader(): ImageLoader {
      return mock(ImageLoader::class.java) // return a Mockito mock of ImageLoader
    }
  }

  companion object {
    const val FAKE_IMAGE_URL = ""
    const val OK_IMAGE_URL = "https://teorico.net/images/test-dgt-1.png"
  }
}