Espresso Testing Framework - Test Recorder

Writing test case is a tedious job. Even though espresso provides very easy and flexible API, writing test cases may be a lazy and time-consuming task. To overcome this, Android studio provides a feature to record and generate espresso test cases. Record Espresso Test is available under the Run menu.

Let us record a simple test case in our HelloWorldApp by following the steps described below,

• Open the Android studio followed by HelloWorldApp application.

• Click Run → Record Espresso test and select MainActivity.

• The Recorder screenshot is as follows,

• Click Add Assertion. It will open the application screen as shown below,

• Click Hello World!. The Recorder screen to Select text view is as follows,

• Again click Save Assertion This will save the assertion and show it as follows,

• Click OK. It will open a new window and ask the name of the test case. The default name is MainActivityTest

• Change the test case name, if necessary.

• Again, click OK. This will generate a file, MainActivityTest with our recorded test case. The complete coding is as follows,

package com.tutorialspoint.espressosamples.helloworldapp;

import android.view.View;
import android.view.ViewGroup;
import android.view.ViewParent;

import org.hamcrest.Description;
import org.hamcrest.Matcher;
import org.hamcrest.TypeSafeMatcher;
import org.junit.Rule;
import org.junit.Test;
import org.junit.runner.RunWith;

import androidx.test.espresso.ViewInteraction;
import androidx.test.filters.LargeTest;
import androidx.test.rule.ActivityTestRule;
import androidx.test.runner.AndroidJUnit4;

import static androidx.test.espresso.Espresso.onView;
import static androidx.test.espresso.assertion.ViewAssertions.matches;
import static androidx.test.espresso.matcher.ViewMatchers.isDisplayed;
import static androidx.test.espresso.matcher.ViewMatchers.withId;
import static androidx.test.espresso.matcher.ViewMatchers.withText;
import static org.hamcrest.Matchers.allOf;

@LargeTest
@RunWith(AndroidJUnit4.class)
public class MainActivityTest {
   @Rule
   public ActivityTestRule<MainActivity> mActivityTestRule = new ActivityTestRule<>(MainActivity.class);
   @Test
   public void mainActivityTest() {
      ViewInteraction textView = onView(
         allOf(withId(R.id.textView_hello), withText("Hello World!"),
         childAtPosition(childAtPosition(withId(android.R.id.content),
         0),0),isDisplayed()));
      textView.check(matches(withText("Hello World!")));
   }
   private static Matcher<View> childAtPosition(
      final Matcher<View> parentMatcher, final int position) {
      return new TypeSafeMatcher<View>() {
         @Override
         public void describeTo(Description description) {
            description.appendText("Child at position " + position + " in parent ");
            parentMatcher.describeTo(description);
         }
         @Override
         public boolean matchesSafely(View view) {
            ViewParent parent = view.getParent();
            return parent instanceof ViewGroup &&
               parentMatcher.matches(parent)&& view.equals(((ViewGroup)
               parent).getChildAt(position));
         }
      };
   }
}

• Finally, run the test using context menu and check whether the test case run.