Your Robotium tests are flaky? not readable? Come to this Tools in Action and discover Espresso, the new testing library for Android. During this live coding presentation, you will learn how to write beautiful tests and take advantage of Espresso features. Par Thomas Guérin, consultant chez Xebia, à Devoxx Belgique 2014.

1. Espresso: What else ?
Thomas Guerin
Xebia France
#Devoxx #AndroidEspresso @Tom404_

2. #Devoxx #AndroidEspresso @Tom404_

3. “My tests last hours !”
#Devoxx #AndroidEspresso @Tom404_

4. “My tests last hours !”
“Testing is sometimes complicated !”
#Devoxx #AndroidEspresso @Tom404_

5. “My tests last hours !”
“Testing is sometimes complicated !”
“My tests randomly fail !”
#Devoxx #AndroidEspresso @Tom404_

6. “My tests last hours !”
“Testing is sometimes complicated !”
“My tests randomly fail !”
“I have to fix the tests for a simple modification in my code”
#Devoxx #AndroidEspresso @Tom404_

7. “My tests last hours !”
“Testing is sometimes complicated !”
“My tests randomly fail !”
“I have to fix the tests for a simple modification in my code”
#Devoxx #AndroidEspresso @Tom404_

8. “My tests last hours !”
“Testing is sometimes complicated !”
“My tests randomly fail !”
“I have to fix the tests for a simple modification in my code”
#Devoxx #AndroidEspresso @Tom404_

9. “My tests last hours !”
“Testing is sometimes complicated !”
“My tests randomly fail !”
“I have to fix the tests for a simple modification in my code”
#Devoxx #AndroidEspresso @Tom404_

10. A test must be …
#Devoxx #AndroidEspresso @Tom404_

11. A test must be …
Simple
#Devoxx #AndroidEspresso @Tom404_

12. A test must be …
Simple Fast
#Devoxx #AndroidEspresso @Tom404_

13. A test must be …
Simple Fast Reliable
#Devoxx #AndroidEspresso @Tom404_

14. A test must be …
Simple Fast Reliable Durable
#Devoxx #AndroidEspresso @Tom404_

15. Bad example
// Start the main activity of the application under test
mActivity = getActivity();
// Get a handle to the Activity object's main UI widget, a Spinner
mSpinner = (Spinner)mActivity.findViewById(com.android.example.spinner.R.id.Spinner01);
// Set the Spinner to a known position
mActivity.setSpinnerPosition(TEST_STATE_DESTROY_POSITION);
// Stop the activity -­‐ The onDestroy() method should save the state of the Spinner
mActivity.finish();
// Re-­‐start the Activity -­‐ the onResume() method should restore the state of the Spinner
mActivity = getActivity();
// Get the Spinner's current position
int currentPosition = mActivity.getSpinnerPosition();
// Assert that the current position is the same as the starting position
assertEquals(TEST_STATE_DESTROY_POSITION, currentPosition);
#Devoxx #AndroidEspresso @Tom404_

16. Bad example
// Start the main activity of the application under test
mActivity = getActivity();
// Get a handle to the Activity object's main UI widget, a Spinner
mSpinner = (Spinner)mActivity.findViewById(com.android.example.spinner.R.id.Spinner01);
// Set the Spinner to a known position
mActivity.setSpinnerPosition(TEST_STATE_DESTROY_POSITION);
// Stop the activity -­‐ The onDestroy() method should save the state of the Spinner
mActivity.finish();
// Re-­‐start the Activity -­‐ the onResume() method should restore the state of the Spinner
mActivity = getActivity();
// Get the Spinner's current position
int currentPosition = mActivity.getSpinnerPosition();
// Assert that the current position is the same as the starting position
assertEquals(TEST_STATE_DESTROY_POSITION, currentPosition);
#Devoxx #AndroidEspresso @Tom404_

17. Robotium
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18. API Overview
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19. API Overview
clickInList(int line, int index)
clickOnActionBarHome()
clickOnButton(int index)
searchText(String text)
pressSoftKeyboardNextButton()
setNavigationDrawer(int status)
Solo
getView(int viewId)
drag(…)
goBack()
clickOnImageButton(int index)
scrollDownList(int index)
clickOnActionBarItem(int id)
getButton(int index)
clearEditText(int index)
scrollDown()
clickOnToggleButton(String text)
scrollToBottom() searchEditText(String text)
pressMenuItem(int index)
pressSoftKeyboardSearchButton()
#Devoxx #AndroidEspresso @Tom404_

20. Basic example
solo.clickOnView(R.id.start_activity_button);
// Wait for a specific condition to occur
solo.waitForCondition(new Condition() {
@Override
public boolean isSatisfied() {
return checkConditionInNewActivity();
}
}, Timeout.getSmallTimeout());
solo.clickOnView(R.id.view_in_new_activity);
#Devoxx #AndroidEspresso @Tom404_

21. Basic example
solo.clickOnView(R.id.start_activity_button);
// Wait for a specific condition to occur
solo.waitForCondition(new Condition() {
@Override
public boolean isSatisfied() {
return checkConditionInNewActivity();
}
}, Timeout.getSmallTimeout());
solo.clickOnView(R.id.view_in_new_activity);
#Devoxx #AndroidEspresso @Tom404_

22. Robotium drawbacks
Flaky tests
Hard to extend
View index based methods
Errors not meaningful
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23. Espresso
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24. Hamcrest
#Devoxx #AndroidEspresso @Tom404_

25. Hamcrest
Library of matchers
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26. Hamcrest
Library of matchers
assertThat("Hello", equalTo("Hello"))
// Syntaxic sugar
assertThat("Hello", is("Hello"))
// A lot of matchers available
allOf not instanceOf hasProperty equalToIgnoringCase
#Devoxx #AndroidEspresso @Tom404_

27. Hamcrest
Library of matchers
assertThat("Hello", equalTo("Hello"))
// Syntaxic sugar
assertThat("Hello", is("Hello"))
// A lot of matchers available
allOf not instanceOf hasProperty equalToIgnoringCase
Easy to compose
#Devoxx #AndroidEspresso @Tom404_

28. Custom matcher
public static Matcher<View> isVisible() {
return new TypeSafeMatcher<View>() {
@Override
public void describeTo(Description description) {
description.appendText("is view visible");
}
@Override
public boolean matchesSafely(View view) {
return view.getVisibility() == View.VISIBLE;
}
};
}
#Devoxx #AndroidEspresso @Tom404_

29. API overview
#Devoxx #AndroidEspresso @Tom404_

30. API overview
Espresso
onView(Matcher<View>)
onData(Matcher<Object>
#Devoxx #AndroidEspresso @Tom404_

31. API overview
ViewMatchers
Espresso withId()
onView(Matcher<View>)
onData(Matcher<Object>
withText(text)
hasSibling(Matcher<View>)
#Devoxx #AndroidEspresso @Tom404_

32. API overview
Espresso
onView(Matcher<View>)
onData(Matcher<Object>
ViewInteraction / DataInteraction
perform(ViewAction)
check(ViewAssertion)
ViewMatchers
withId()
withText(text)
hasSibling(Matcher<View>)
#Devoxx #AndroidEspresso @Tom404_

33. API overview
Espresso
onView(Matcher<View>)
onData(Matcher<Object>
ViewInteraction / DataInteraction
perform(ViewAction)
check(ViewAssertion)
ViewMatchers
withId()
withText(text)
hasSibling(Matcher<View>)
ViewActions
click()
typeText(text)
#Devoxx #AndroidEspresso @Tom404_

34. API overview
Espresso
onView(Matcher<View>)
onData(Matcher<Object>
ViewInteraction / DataInteraction
perform(ViewAction)
check(ViewAssertion)
ViewMatchers
withId()
withText(text)
hasSibling(Matcher<View>)
ViewActions
click()
typeText(text)
ViewAssertions
doesNotExist()
matches(Matcher<View>)
#Devoxx #AndroidEspresso @Tom404_

35. Goodbye flakiness
#Devoxx #AndroidEspresso @Tom404_

36. Goodbye flakiness
For each test action, Espresso will :
#Devoxx #AndroidEspresso @Tom404_

37. Goodbye flakiness
For each test action, Espresso will :
1. Wait until the app is idle
#Devoxx #AndroidEspresso @Tom404_

38. Goodbye flakiness
For each test action, Espresso will :
1. Wait until the app is idle
2. Run on the UI thread
#Devoxx #AndroidEspresso @Tom404_

39. Goodbye flakiness
For each test action, Espresso will :
1. Wait until the app is idle
2. Run on the UI thread
3. Wait until completion
#Devoxx #AndroidEspresso @Tom404_

40. Goodbye flakiness
For each test action, Espresso will :
1. Wait until the app is idle
2. Run on the UI thread
3. Wait until completion
4. Check the result
#Devoxx #AndroidEspresso @Tom404_

41. Goodbye flakiness
For each test action, Espresso will :
1. Wait until the app is idle
2. Run on the UI thread
3. Wait until completion
4. Check the result
#Devoxx #AndroidEspresso @Tom404_

42. Demo
#Devoxx #AndroidEspresso @Tom404_