Pfthb

I would like to test if my method "OnClick" that redirect me to another activity is working. But I have no idea how to do it in a unit test..

public void onClickManageServiceButton(View view){ 
 Intent intent = new Intent(getApplicationContext(), ServiceManagement.class);
 startActivity(intent);

You should use Robolectric to test that.

Add the testImplementation in the gradle for Robolectric
http://robolectric.org/getting-started/

@RunWith(RobolectricTestRunner.class) 
public class ACTUAL_ACTIVITYTest 

@Test
public void clickingLogin_shouldStart ServiceManagementActivity() 
 WelcomeActivity activity = Robolectric.setupActivity(ACTUAL_ACTIVITY.class);
 activity.onClickManageServiceButton(null);

 Intent expectedIntent = new Intent(activity, ServiceManagement.class);
 Intent actual = shadowOf(RuntimeEnvironment.application).getNextStartedActivity();
 assertEquals(expectedIntent.getComponent(), actual.getComponent());
 

where ACTUAL_ACTIVITY is the activity where you have the method onClickManageServiceButton.

Trick: "Press CMD + SHIFT + T" in the activity class and you will have a quick action to create a test for that activity

You can do this easily with the Espresson Intents API:

In your test, set up an IntentsTestRule that will record intents being fired.

@Rule public IntentsTestRule<MyActivity> intentsTestRule =
 new IntentsTestRule<>(MyActivity.class);

In your test, launch your activity, trigger the method under test, and assert:

@Test
public void onClickManageServiceButton() 
 // By default the rule launch your activity, so it's running by the time test starts

 // Assuming the method to test is on your activity under test...
 // You many need to find a View or mock one out to pass to the method.
 mIntentsTestRule.getActivity().onClickManageServiceButton(null);

 // Espresso will have recorded the intent being fired - now use the intents
 // API to assert that the expected intent was launched...
 Intents.intended(hasComponent(ServiceManagement.class.getName()));

Check the Intents and IntentMatchers class references for more on what you can do assert intents are fired.

Hope that helps!