sanogueralorenzo

class CounterViewModelTest {

    private lateinit var viewModel: CounterViewModel

    @Rule
    @JvmField
    val instantTaskExecutorRule: TestRule = InstantTaskExecutorRule()

    @Before
    fun setUp() {

sanogueralorenzo

private fun updateUsers(resource: Resource<List<Users>>?) {
    resource?.let {
        when (it.state) {
            ResourceState.LOADING -> loading.visible()
            ResourceState.SUCCESS -> loading.gone()
            ResourceState.ERROR -> loading.gone()
        }
        it.data?.let { adapter.addItems(it) }
        it.message?.let { snackBar.show() }
    }

sanogueralorenzo

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
      
        val vm = ViewModelProviders.of(this)[CounterViewModel::class.java]
        vm.counter.observe(this, Observer({ textView.text = it.toString() }))
        button.setOnClickListener { vm.onButtonClick() }
    }

sanogueralorenzo

class CounterViewModel : ViewModel() {
    val counter = MutableLiveData<Int>()
    var number = 0
    fun onButtonClick() = counter.setValue(++number)
}

sanogueralorenzo

class UserListViewModel : ViewModel() {
    val users = MutableLiveData<Resource<List<User>>>()
  
    private fun loading() = users.setLoading() 

    private fun success(userList: List<User>) = users.setSuccess(userList)

    private fun error(throwable: Throwable) = users.setError(throwable.message)
}

sanogueralorenzo

data class Resource<out T> constructor(
    val state: ResourceState,
    val data: T? = null,
    val message: String? = null
)

sanogueralorenzo

sealed class ResourceState {
    object LOADING : ResourceState()
    object SUCCESS : ResourceState()
    object ERROR : ResourceState()
}

sanogueralorenzo

dependencies {
    //Other dependencies...
    implementation "android.arch.lifecycle:extensions:1.1.0"
    annotationProcessor "android.arch.lifecycle:compiler:1.1.0"
    testImplementation "android.arch.core:core-testing:1.1.0"
}