Espresso - How can I check if an activity is launched after performing a certain action?

Question

the following is one of my Espresso test cases.

    public void testLoginAttempt() {
        Espresso.onView(ViewMatchers.withId(R.id.username)).perform(View         


        

Answer 1

Make sure the Espresso intent library is in the gradle dependencies

androidTestImplementation "com.android.support.test.espresso:espresso-intents:3.0.1"

Then import these two in your test file

import static android.support.test.espresso.intent.Intents.intended
import static android.support.test.espresso.intent.matcher.IntentMatchers.hasComponent

Then add IntentsTestRule in your test class

@Rule
@JvmField
val mainActivityRule = IntentsTestRule(MainActivity::class.java)

Finally check the activity has launched intent

@Test
fun launchActivityTest() {
    onView(ViewMatchers.withId(R.id.nav_wonderful_activity))
            .perform(click())

    intended(hasComponent(WonderfulActivity::class.java!!.getName()))
}

Answer 2

You may do it as follows:

    @Test
public void testLoginAttempt() {
    Espresso.onView(ViewMatchers.withId(R.id.username)).perform(ViewActions.clearText()).perform(ViewActions.typeText("nonexistinguser@example.com"));
    Espresso.onView(ViewMatchers.withId(R.id.username)).perform(ViewActions.clearText()).perform(ViewActions.typeText("invalidpassword"));

    Intents.init();
    Espresso.onView(ViewMatchers.withId(R.id.login_button)).perform(ViewActions.click());
    Intents.release();
}

java.lang.NullPointerException is thrown if Intents.init() is not called.