How to take screenshot at the point where test fai

问题:

I am looking for a way to take a screenshot of device after test failed and before get closed.

回答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));
  }
};

回答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());

回答3:

I haven't used screenshots in my Android testing yet, but I know some solutions, which might be useful:

Spoon

the best way to do it would be use Emma or Spoon framework.

Here you would find some useful information how to do it: http://elekslabs.com/2014/05/creating-test-reports-for-android-with-spoon-and-emma.html

Visit also Spoon's official Github site: https://github.com/square/spoon and its Gradle's plugin: https://github.com/stanfy/spoon-gradle-plugin

and check related topic: How to get Spoon to take screenshots for Espresso tests?

screenshot-tests-for-android/

You can also try this Facebook's library: https://facebook.github.io/screenshot-tests-for-android/

Robotium's ScreenshotTaker

As I've already know, with Robotium test framework is possible to create test with screenshots. Check: Correct way to take screenshot with Robotium and Cucumber

If you don't want to use any library, check source code of Robotium framework class called ScreenshotTaker.java[click on link to see] and write your own ScreenshotTaker class.

Hope it will help.

回答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

回答5:

I made some improvements on this answer. No need to add an extra dependency for UiAutomator and it also works below api level 18.

public class ScreenshotTestWatcher extends TestWatcher
{
   private static Activity currentActivity;

   @Override
   protected void failed(Throwable e, Description description)
   {
      Bitmap bitmap;

      if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2)
      {
         bitmap = getInstrumentation().getUiAutomation().takeScreenshot();
      }
      else
      {
         // only in-app view-elements are visible.
         bitmap = Screenshot.capture(getCurrentActivity()).getBitmap();
      }

      // Save to external storage '/storage/emulated/0/Android/data/[package name app]/cache/screenshots/'.
      File folder = new File(getTargetContext().getExternalCacheDir().getAbsolutePath() + "/screenshots/");
      if (!folder.exists())
      {
         folder.mkdirs();
      }

      storeBitmap(bitmap, folder.getPath() + "/" + getFileName(description));
   }

   private String getFileName(Description description)
   {
      String className = description.getClassName();
      String methodName = description.getMethodName();
      String dateTime = Calendar.getInstance().getTime().toString();

      return className + "-" + methodName + "-" + dateTime + ".png";
   }

   private void storeBitmap(Bitmap bitmap, String path)
   {
      BufferedOutputStream out = null;
      try
      {
         out = new BufferedOutputStream(new FileOutputStream(path));
         bitmap.compress(Bitmap.CompressFormat.PNG, 100, out);
      }
      catch (IOException e)
      {
         e.printStackTrace();
      }
      finally
      {
         if (out != null)
         {
            try
            {
               out.close();
            }
            catch (IOException e)
            {
               e.printStackTrace();
            }
         }
      }
   }

   private static Activity getCurrentActivity()
   {
      getInstrumentation().runOnMainSync(new Runnable()
         {
            public void run()
            {
               Collection resumedActivities = ActivityLifecycleMonitorRegistry.getInstance().getActivitiesInStage(
                     RESUMED);
               if (resumedActivities.iterator().hasNext())
               {
                  currentActivity = (Activity) resumedActivities.iterator().next();
               }
            }
         });

      return currentActivity;
   }
}

Then include the following line in your test class:

@Rule
public TestRule watcher = new ScreenshotTestWatcher();

回答6:

@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