How to take screenshot at the point where test fail in Espresso?

android testing automated-tests android-espresso

15,813

Solution 1

Easiest way that I found:

@Rule
public TestRule watcher = new TestWatcher() {
  @Override
  protected void failed(Throwable e, Description description) {
    // Save to external storage (usually /sdcard/screenshots)
    File path = new File(Environment.getExternalStorageDirectory().getAbsolutePath()
        + "/screenshots/" + getTargetContext().getPackageName());
    if (!path.exists()) {
      path.mkdirs();
    }

    // Take advantage of UiAutomator screenshot method
    UiDevice device = UiDevice.getInstance(InstrumentationRegistry.getInstrumentation());
    String filename = description.getClassName() + "-" + description.getMethodName() + ".png";
    device.takeScreenshot(new File(path, filename));
  }
};

Solution 2

Another improvement to previous answers. I'm using the experimental Screenshot API

public class ScreenshotTestRule extends TestWatcher {

  @Override
  protected void failed(Throwable e, Description description) {
    super.failed(e, description);

    takeScreenshot(description);
  }

  private void takeScreenshot(Description description) {
    String filename = description.getTestClass().getSimpleName() + "-" + description.getMethodName();

    ScreenCapture capture = Screenshot.capture();
    capture.setName(filename);
    capture.setFormat(CompressFormat.PNG);

    HashSet<ScreenCaptureProcessor> processors = new HashSet<>();
    processors.add(new CustomScreenCaptureProcessor());

    try {
      capture.process(processors);
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
}

I've created CustomScreenCaptureProcessor because BasicScreenCaptureProcessor uses /sdcard/Pictures/ folder and I encountered IOExceptions on some devices when creating the folder/image. Please note that you need to place your processor in the same package

package android.support.test.runner.screenshot;

public class CustomScreenCaptureProcessor extends BasicScreenCaptureProcessor {    
  public CustomScreenCaptureProcessor() {
    super(
        new File(
            InstrumentationRegistry.getTargetContext().getExternalFilesDir(DIRECTORY_PICTURES),
            "espresso_screenshots"
        )
    );
  }
}

Then, in your base Espresso test class just add

@Rule
public ScreenshotTestRule screenshotTestRule = new ScreenshotTestRule();

If you wish to use some protected folder, this did the trick on an emulator, tho it didn't work on a physical device

@Rule
public RuleChain screenshotRule = RuleChain
      .outerRule(GrantPermissionRule.grant(permission.WRITE_EXTERNAL_STORAGE))
      .around(new ScreenshotTestRule());

Solution 3

@Maragues answer ported to Kotlin:

Helper classes:

package utils

import android.graphics.Bitmap
import android.os.Environment.DIRECTORY_PICTURES
import androidx.test.platform.app.InstrumentationRegistry.getInstrumentation
import androidx.test.runner.screenshot.BasicScreenCaptureProcessor
import androidx.test.runner.screenshot.ScreenCaptureProcessor
import androidx.test.runner.screenshot.Screenshot
import org.junit.rules.TestWatcher
import org.junit.runner.Description
import java.io.File
import java.io.IOException

class IDTScreenCaptureProcessor : BasicScreenCaptureProcessor() {
    init {
        mTag = "IDTScreenCaptureProcessor"
        mFileNameDelimiter = "-"
        mDefaultFilenamePrefix = "Giorgos"
        mDefaultScreenshotPath = getNewFilename()
    }

    private fun getNewFilename(): File? {
        val context = getInstrumentation().getTargetContext().getApplicationContext()
        return context.getExternalFilesDir(DIRECTORY_PICTURES)
    }
}

class ScreenshotTestRule : TestWatcher() {
    override fun finished(description: Description?) {
        super.finished(description)

        val className = description?.testClass?.simpleName ?: "NullClassname"
        val methodName = description?.methodName ?: "NullMethodName"
        val filename = "$className - $methodName"

        val capture = Screenshot.capture()
        capture.name = filename
        capture.format = Bitmap.CompressFormat.PNG

        val processors = HashSet<ScreenCaptureProcessor>()
        processors.add(IDTScreenCaptureProcessor())

        try {
            capture.process(processors)
        } catch (ioException: IOException) {
            ioException.printStackTrace()
        }
    }
}

Usage:

import androidx.test.espresso.Espresso.onView
import androidx.test.espresso.assertion.ViewAssertions.matches
import androidx.test.espresso.matcher.ViewMatchers.isCompletelyDisplayed
import androidx.test.espresso.matcher.ViewMatchers.withText
import androidx.test.ext.junit.runners.AndroidJUnit4
import androidx.test.filters.LargeTest
import androidx.test.rule.ActivityTestRule
import org.junit.Rule
import org.junit.Test
import org.junit.runner.RunWith
import utils.ScreenshotTestRule

@RunWith(AndroidJUnit4::class)
@LargeTest
class DialogActivityTest {

    @get:Rule
    val activityRule = ActivityTestRule(DialogActivity::class.java)

    @get:Rule
    val screenshotTestRule = ScreenshotTestRule()

    @Test
    fun dialogLaunch_withTitleAndBody_displaysDialog() {
        // setup
        val title = "title"
        val body = "body"

        // assert
        onView(withText(title)).check(matches(isCompletelyDisplayed()))
        onView(withText(body)).check(matches(isCompletelyDisplayed()))
    }


}

Libraries declared in app's build.gradle:

androidTestImplementation "androidx.test.espresso:espresso-core:3.1.1"
androidTestImplementation "androidx.test.espresso:espresso-intents:3.1.1"
androidTestImplementation "androidx.test.ext:junit:1.1.0"
androidTestImplementation "androidx.test:runner:1.1.1"
androidTestImplementation "androidx.test:rules:1.1.1"

This setup saves a screenshot every time a test finished in the folder: /sdcard/Android/data/your.package.name/files/Pictures Navigate there via Android Studio's Device File Explorer (on the right sidebar)

If you like to save screenshots only for failed tests, override the failed method of TestWatcher instead of the finished

Solution 4

Writing a custom TestWatcher like the other answers explained is the way to go.

BUT (and it took us a long time to notice it) there is a caveat: The rule might fire too late, i.e. after your activity was already destroyed. This leaves you with a screenshot of the device's home screen and not from the failing activity.

You can solve this using RuleChain: Instead of writing

@Rule
public final ActivityTestRule<MainActivity> _activityRule = new ActivityTestRule<>(MainActivity.class);

@Rule
public ScreenshotTestWatcher _screenshotWatcher = new ScreenshotTestWatcher();

You have to write:

private final ActivityTestRule<MainActivity> _activityRule = new ActivityTestRule<>(MainActivity.class);

@Rule
public final TestRule activityAndScreenshotRule = RuleChain
        .outerRule(_activityRule)
        .around(new ScreenshotTestWatcher());

This makes sure that the screenshot is taken first and then the activity is destroyed

View more solutions

15,813