Problems to sets the fragment from a FragmentScenario to be used from DataBindingIdlingResource

Question

I'm following this Google Codelab and at the page 8 (Task: End-to-End Testing with Data Binding), at step 8 (Write DataBindingIdlingResource) you have to create a file called DataBindingIdlingResource.kt.

class DataBindingIdlingResource : IdlingResource {
    [...]
}

private fun View.getBinding(): ViewDataBinding? = DataBindingUtil.getBinding(this)

/**
 * Sets the activity from an [ActivityScenario] to be used from [DataBindingIdlingResource].
 */
fun DataBindingIdlingResource.monitorActivity(
    activityScenario: ActivityScenario<out FragmentActivity>
) {
    activityScenario.onActivity {
        this.activity = it
    }
}

/**
 * Sets the fragment from a [FragmentScenario] to be used from [DataBindingIdlingResource].
 */
fun DataBindingIdlingResource.monitorFragment(fragmentScenario: FragmentScenario<out Fragment>) {
    fragmentScenario.onFragment {
        this.activity = it.requireActivity()
    }
}

The problem: is the last function fun DataBindingIdlingResource.monitorFragment because fragmentScenario.onFragment provides only onFragment(action: Nothing) and not onFragment {}.

How Can I solve this issue? Thanks.

I am having the same issue and confused why the type is marked as Nothing - did you figure it out? — dazza5000, Jul 08 '21 at 13:17
The definition does not show a type of `Nothing` https://developer.android.com/reference/kotlin/androidx/fragment/app/testing/FragmentScenario#onfragment — dazza5000, Jul 08 '21 at 14:21

score 7 · Answer 1 · answered Jul 26 '21 at 19:47

7

I've solved it by changing the definition to

fun <T : Fragment> DataBindingIdlingResource.monitorFragment(fragmentScenario: FragmentScenario<T>) {

answered Jul 26 '21 at 19:47

moozg

406
3
12

score 3 · Accepted Answer · answered Jan 28 '22 at 00:27

3

fun DataBindingIdlingResource.monitorFragment(fragmentScenario: FragmentScenario<Fragment>) {
  fragmentScenario.onFragment { fragment ->
      this.activity = fragment.requireActivity()
  }
}

This is working for me.

answered Jan 28 '22 at 00:27

Emilio Hoffmann

274
2
11

Problems to sets the fragment from a FragmentScenario to be used from DataBindingIdlingResource

2 Answers2