Introduction to Android Espresso Testing and Spoon

Espresso UI test automation framework is Google’s de-facto testing platform for Android app developers.

The way it is easily used from within Android Studio and IntelliJ IDEA IDE’s makes it a powerful tool that differentiates it from other open-source cross-platform solutions such as Appium and other commercial tools.

Before drilling into basic setup and execution of an Espresso simple test, let’s first understand some of the basics:

  • Espresso is an Android only test automation framework (not cross platform like Appium/Selenium)
  • Espresso requires a separate APK package running in parallel with the application under test
  • Espresso is not Dev-Language Free framework like Appium (that supports Java, JS, Python, C#, Perl)

Positive Motivations to Use Espresso

  • The Espresso framework is embedded into the entire dev workflow and IDE, and that makes the adoption and leverage higher
  • Espresso can be used to do a quick post-commit validation of a fix or new code implementation, and also as part of a larger test scale within the CI workflow.
  • Espresso provides fast feedback to its users which is a big advantage since it is running on the device/emulator side-by-side with the app
  • Espresso supports annotations to determine the test execution scope (small/medium/large) which organizes the overall testing cycle for both dev and test
  • Espresso has unique synchronization method in its core making the tests less flaky and more robust. It will pass to the next test step in the code only once the view is available on the device screen in opposed to other tools that can easily fail without having timers, validation points and more.

Basic Espresso Framework Methods:

Espresso framework allows the automation developer to manipulate the test using 3 concepts:

  1. View Matchers
  2. View Actions
  3. View Assertions

basicses

As seen in the above definition, onView(xxx) of a specific object on the app screen, an Action will be performed and an Assertion will be made to validate the end result.

Espresso Setup

The setup within Android studio is quite simple, and there is plenty of documentation in the google community around it.

The developer will edit his build.Gradle file for the application under test to include the Espresso framework dependency, the JUnit version, and the InstrumentationRunner (see below example)

gradlesample

Once the above is done, it is time to create for the corresponding app the test class.

This class will need to include through Import, few libraries that are required by the Espresso test (below example)

import

Test Code Implementation

In order to develop an Espresso UI automation, the developer must have the unique object identifiers for the application under test.

To study the app objects (Hamcrest Matchers) the developer can use various methods:

  1. UIAutomation.bat tool that is built into the Android Studio SDK
  2. All resource ID’s should be automatically be stored in a dynamically generated R.java file
  3. Object spy within tools that supports Espresso (Perfecto and others).

Looking at a simple TipCalculator application, you can see through the UIAutomator spy, that the text box object ID is named bill_value

uiautomator

In the R.java file, it will look like this (choose the best method you find comfortable)

rjava

When implementing the Espresso test code, we will leverage the ObjectID as part of the onView method to perform a Click prior to entering an input value to that text box.

code1

In order to perform a type of value into the above Total Bill text box, we will use the 2nd method provided by Espresso, that is. Perform:

code2

Once we are done with the action, we would like to assure that the result of that action is as expected, and this is when the developer will use the assertion method .Check

code3

Finally, once the entire test suite is implemented and ready – running the test from Android Studio is very simple.

Select the Test class from the Edit Configurations menu in Android studio and chose run. Select your target (ADB connected device, cloud devices, emulators).

code4

At the end of a test, a basic test report will be provided to the user.

Running Espresso Tests in Parallel – Using Spoon

No test engineer or developer will be quite unless it validates the functionality of his app on multiple devices and emulators. For that, there is another widely used tool called Spoon (there are also cloud-based solutions as mentioned above that support parallel execution on real devices). This tool, will collect all the target devices (that are visible via adb devices) test results and aggregate them into one HTML view that can be easily investigated.

example_main

In order to leverage Spoon, please download the Gradle for spoon plugin and install it. Post installation, configure as follows

gradlespoon

By default, Spoon will run your tests on all ADB connected devices, however, if you want to run concrete devices and skip others in order to reproduce a specific defect on 1 device, you can configure spoon accordingly

spoon2

Good Luck!

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4 Benefits of Using the Espresso Test Automation Tool

If you’re an Android developer, you’re probably familiar with Google’s Espresso test automation framework. As an open-source tool, it’s very easy for developers to use and extend within their working environment (Android Studio IDE).

But before discussing the benefits of Espresso, let’s understand the motivations and pains developers and test automation engineers face today while trying to validate their Android application (APK) throughout the build/dev/test workflow.

  • Each build needs to be validated after code changes are made.
  • Dependencies on remote servers and other workstations for testing slow down the process.
  • Unit and functional tests need to be easy to execute from both an IDE and continuous integration perspective.
  • Apps need to be tested using the latest Android OS APIs that support new platform features and OS versions.
  • Testing needs to occur on both emulators and real devices.

In light of these challenges, it’s clear why the adoption of the Espresso automation framework is high. Even though Espresso is an instrumentation-based test framework, it has many benefits to both developers and test automation engineers. It uses Junit underneath the hood, so Espresso is easy to use within leading IDEs and provides useful testing annotations and assertions. It’s also fully integrated within the leading Google Android IDE – Android Studio.

Here are four main benefits of using Espresso:

1. Espresso workflow is simple to use

The way Espresso works is by allowing developers to build a test suite as a stand-alone APK that can be installed on the target devices alongside the application under test and be executed very quickly.

2. Fast and reliable feedback to developers

As developers are trying to accelerate deployment, Espresso gives them fast feedback on their code changes so they can move on to the next feature or defect fix; having a robust and fast test framework plays a key role.

Espresso does not require any server (like Selenium Remote WebDriver) to communicate with; instead it runs side-by-side with the app and delivers very fast (minutes) test results to the developer.

3. Less mobile testing flakiness

Because Espresso offers a synchronized method of execution, the stability of the test cycle is very high. There’s a built-in mechanism in Espresso that, prior to moving to the next steps in the test, validates that the Element or Object is actually displayed on the screen. This eliminates test execution from breaking when confronted with “objects not detected” and other errors.

4. Developing Espresso test automation isn’t hard

Developing Espresso test automation is quite easy. It is based on Java and Junit, which is a core skillset for any Android app developer. Because Espresso works seamlessly within the Android Studio IDE, there’s no setup or ramping up and no “excuses” – to actually shift quality in the in-cycle stage of the app SDLC.

In addition to the above, there is of course the large community powered by Google that pushes the Espresso test automation framework and allow easy and fast ramp up for newcomers.

Learn more using the Espresso Cheat sheet below:

Espresso Test Automation Framework

Perfecto is offering support for both Android Studio IDE as well as the ability to install and launch an Espresso test suite (APK) on real devices in the cloud across various locations and user conditions. For more information, please refer to the Perfecto Community and search for “Android Studio” or “Espresso.”