JUnit 5 Extension for the ActivityScenario API, provided by the AndroidX test core library.

This extension is used in lieu of a JUnit 4 Rule to automatically launch/stop an ActivityScenario for each test case.

To use this extension in your test class, add it as a non-private instance field to your test class, using one of the factory methods named launch. Then, annotate this field with JUnit Jupiter's RegisterExtension annotation. In Kotlin, also add JvmField or else the generated property won't be visible to the TestEngine!

// Java
class MyActivityTests {

  @RegisterExtension
  final ActivityScenarioExtension<MyActivity> scenarioExtension = ActivityScenarioExtension.launch(MyActivity.class);
}

// Kotlin
class MyActivityTests {

  @JvmField
  @RegisterExtension
  val scenarioExtension = ActivityScenarioExtension.launch<MyActivity>()
}

In your test method, you can obtain a reference to the scenario in two ways:

A) You obtain it from the extension directly through its accessor method:

// Java
class MyActivityTests {

  @RegisterExtension
  final ActivityScenarioExtension<MyActivity> scenarioExtension = ActivityScenarioExtension.launch(MyActivity.class);

  @Test
  void myTest() {
    ActivityScenario<MyActivity> scenario = scenarioExtension.getScenario();
    // Use the scenario...
  }
}

// Kotlin
class MyActivityTests {

  @JvmField
  @RegisterExtension
  val scenarioExtension = ActivityScenarioExtension.launch<MyActivity>()

  @Test
  fun myTest() {
    val scenario = scenarioExtension.scenario
    // Use the scenario...
  }
}

B) You add a parameter of type ActivityScenario, with the activity class as its generic type:

// Java
class MyActivityTests {

  @RegisterExtension
  final ActivityScenarioExtension<MyActivity> scenarioExtension = ActivityScenarioExtension.launch(MyActivity.class);

  @Test
  void myTest(ActivityScenario<MyActivity> scenario) {
    // Use the scenario...
  }
}

// Kotlin
class MyActivityTests {

  @JvmField
  @RegisterExtension
  val scenarioExtension = ActivityScenarioExtension.launch<MyActivity>()

  @Test
  fun myTest(scenario: ActivityScenario<MyActivity>) {
    // Use the scenario...
  }
}