FragmentScenario

Kotlin |Java

public final class FragmentScenario<F extends Fragment>

FragmentScenario provides API to start and drive a Fragment's lifecycle state for testing. It works with arbitrary fragments and works consistently across different versions of the Android framework.

FragmentScenario only supports androidx.fragment.app.Fragment. If you are using a deprecated fragment class such as android.support.v4.app.Fragment or android.app.Fragment, please update your code to androidx.fragment.app.Fragment.

If your testing Fragment has a dependency to specific theme such as Theme.AppCompat, use the theme ID parameter in launch method.

Parameters
`<F extends Fragment>`	The Fragment class being tested

See also
`ActivityScenario`	a scenario API for Activity

Summary

Nested types
`FragmentScenario.Companion`
`FragmentScenario.FragmentAction`	FragmentAction interface should be implemented by any class whose instances are intended to be executed by the main thread.

Public methods
`void`	`close()` Finishes the managed fragments and cleans up device's state.
`final @NonNull FragmentScenario<@NonNull F>`	`moveToState(@NonNull Lifecycle.State newState)` Moves Fragment state to a new state.
`final @NonNull FragmentScenario<@NonNull F>`	`onFragment(@NonNull FragmentScenario.FragmentAction<@NonNull F> action)` Runs a given `action` on the current Activity's main thread.
`final @NonNull FragmentScenario<@NonNull F>`	`recreate()` Recreates the host Activity.

Extension functions
`final @NonNull T`	`<F extends Fragment, T extends Object> FragmentScenarioKt.withFragment( @NonNull FragmentScenario<@NonNull F> receiver, @NonNull Function1<@NonNull F, @NonNull T> block )` Run `block` using `FragmentScenario.onFragment`, returning the result of the `block`.

Public methods

close

@NonNull
public void close()

Finishes the managed fragments and cleans up device's state. This method blocks execution until the host activity becomes Lifecycle.State.DESTROYED.

moveToState

@NonNull
public final FragmentScenario<@NonNull F> moveToState(@NonNull Lifecycle.State newState)

Moves Fragment state to a new state.

If a new state and current state are the same, this method does nothing. It accepts CREATED, STARTED, RESUMED, and DESTROYED. DESTROYED is a terminal state. You cannot move to any other state after the Fragment reaches that state.

This method cannot be called from the main thread.

onFragment

@NonNull
public final FragmentScenario<@NonNull F> onFragment(@NonNull FragmentScenario.FragmentAction<@NonNull F> action)

Runs a given action on the current Activity's main thread.

Note that you should never keep Fragment reference passed into your action because it can be recreated at anytime during state transitions.

Throwing an exception from action makes the host Activity crash. You can inspect the exception in logcat outputs.

This method cannot be called from the main thread.

recreate

@NonNull
public final FragmentScenario<@NonNull F> recreate()

Recreates the host Activity.

After this method call, it is ensured that the Fragment state goes back to the same state as its previous state.

This method cannot be called from the main thread.

Extension functions