Skip to main content

Discovering Espresso for Android: matching and asserting view with text.

After more than a month of using great test tool from Google - Espresso for Android, I'd like to share with you some of my experience. I assume that you've already added espresso jar into your project, spent some time playing with Espresso samples and have basic understanding how this tool works.

In this post I'll show how to match particular view with text or assert that it contains (or not) specified Strings. Before we start, you have to take a look at Hamcrest matchers - Hamcrest tutorial and API Reference Documentation, which are used together with Espresso's ViewAssertions and ViewMatchers and included into Espresso standalone library. Pay more attention to Matcher<java.lang.String> matchers.

So, here we go. For simplicity following String "XXYYZZ" will be used as a expected text pattern.
Espresso ViewMatchers class implements two String matcher methods withText() and withContentDescription() which will match a view which text is equal to specified expectedText or specified expectedContentDescriptionText parameter passed into it. 
onView(withText("XXYYZZ")).perform(click());
onView(withContentDescription("XXYYZZ")).perform(click());

 

Using Hamcrest String matchers we can create more flexible matcher combinations:

 - matching a view which text starts with "XXYY" pattern:
onView(withText(startsWith("XXYY"))).perform(click());
 - matching a view which text ends with "YYZZ" pattern:
onView(withText(endsWith("YYZZ"))).perform(click());
 - assert that text of a particular view with specified R.id has content description which contains "YYZZ" string anywhere:
onView(withId(R.id.viewId)).check(matches(withContentDescription(containsString("YYZZ"))));
 - matching a view which text is equal to the specified string, ignoring case:
onView(withText(equalToIgnoringCase("xxYY"))).perform(click());
 - matching a view which text is equal to the specified text when whitespace differences are (mostly) ignored:
onView(withText(equalToIgnoringWhiteSpace("XX YY ZZ"))).perform(click());
 - assert that text of a particular view with specified R.id does not contain "YYZZ" string:
onView(withId(R.id.viewId)).check(matches(withText(not(containsString("YYZZ")))));

 

 Adding allOf() or anyOf() Hamcrest Core matchers gives us even more power:

 - assert that text of a particular view with specified R.id doesn't start with "ZZ" string and contains "YYZZ" string anywhere:
onView(withId(R.id.viewId))
    .check(matches(allOf(withText(not(startsWith("ZZ"))), withText(containsString("YYZZ")))));
- assert that text of a particular view with specified R.id ends with "ZZ" string or contains "YYZZ" string anywhere:
onView(withId(R.id.viewId))
    .check(matches(anyOf(withText(endsWith("ZZ")), withText(containsString("YYZZ")))));
The last note - to use all of mentioned above ViewAssertions, ViewMatchers and Hamcrest matchers just add below imports:
import static com.google.android.apps.common.testing.ui.espresso.Espresso.onView;
import static com.google.android.apps.common.testing.ui.espresso.assertion.ViewAssertions.matches;
import static com.google.android.apps.common.testing.ui.espresso.matcher.ViewMatchers.withId;
import static com.google.android.apps.common.testing.ui.espresso.matcher.ViewMatchers.withText;
import static com.google.android.apps.common.testing.ui.espresso.matcher.ViewMatchers.withContentDescription;
import static org.hamcrest.Matchers.not;
import static org.hamcrest.Matchers.allOf;
import static org.hamcrest.Matchers.anyOf;
import static org.hamcrest.Matchers.containsString;
import static org.hamcrest.Matchers.startsWith;
import static org.hamcrest.Matchers.endsWith;
import static org.hamcrest.Matchers.equalToIgnoringCase;
import static org.hamcrest.Matchers.equalToIgnoringWhiteSpace;
So, basically it. If you stuck at some point and don't have an idea how to proceed, you can ask a question in androit-test-kit Google group. You'll probably get an answer from co-author of Espresso tool - +Valera Zakharov or other experienced users.

Thanks for reading!
Labels:

Comments

Post a Comment

Popular posts from this blog

Espresso & UIAutomator - the perfect tandem

Espresso for Android is perfect and fast test automation framework, but it has one important limitation - you are allowed to operate only inside your app under test context.

That means that it is not possible to automate tests for such app features like:

application push notificationscontact synchronizationnavigating from another app to your app under test,
since you have to deal with other apps from the mobile device - Notification Bar, Contacts or People app, etc. 
In fact it wasn't possible until the release of UIAutomator 2.0. As stated in Android Developers blog post - "...Most importantly, UI Automator is now based on Android Instrumentation...".  And because of that we can run UIAutomator tests as well as Espresso tests using Instrumentation test runner.

In addition to that we can combine UIAutomator tests together with Espresso tests and this gives us the real power and control over the phone and application under test.

In the below example I'll explain  how…
Post a Comment
Read more

Discovering Espresso for Android: how to get current activity?

I see a lot of questions regarding getting current activity while testing with Espresso for Android across multiple activities. Below is the solution:
public Activity getActivityInstance(){ getInstrumentation().runOnMainSync(new Runnable() { public void run() { Collection<Activity> resumedActivities = ActivityLifecycleMonitorRegistry.getInstance().getActivitiesInStage(Stage.RESUMED); for (Activity act: resumedActivities){ Log.d("Your current activity: ", act.getClass().getName()); currentActivity = act; break; } } }); return currentActivity; } The thing is that getActivitiesInStage(Stage.RESUMED) returns us all activities in RESUMED state, and the activity which is currently displayed on screen, will be the first one in list.

Update for Espresso 2.0 - you have to add below imports and slightly modify your method:
import static android.support.test.runner.life…
Post a Comment
Read more