UI testing examines the visual elements of an application that users interact with. In Android ecosystem, automated UI testing is facilitated through testing libraries and tools, allowing developers to write UI or instrumentation tests in the app project directory.
What is Espresso?
Espresso is a robust UI testing framework for Android that offers API methods to write UI tests with human-readable syntax. It provides methods to select a UI element (view), perform actions like clicking or scrolling, and verify the state and content of views.
Setting Up Espresso
Establishing the Espresso framework is a straightforward process. In your app-level build.gradle file, you add the required Espresso dependencies and click on ‘Sync now’. You are then ready to begin writing your tests in the androidTest directory.
Creating Your First Espresso Test
The process of creating your first Espresso Test involves designing the app layout, coding the app logic, adding Espresso dependencies to your project, generating a test class for the Main Activity, and writing the first Espresso test.
Record an Espresso Test
The Espresso Test Recorder tool allows you to create UI tests without writing any test code. By recording a test scenario, you can log your interactions with a device and add assertions to verify UI elements in specific snapshots of your app.
Adding Assertions to Verify UI Elements
Assertions ensure the existence or contents of a View element through three main types: “text is”, “exists”, and “does not exist”. You can add an assertion to your test by clicking on “Add Assertion” and selecting the View element and assertion type in the Edit assertion box.
Saving a Recording
After you’ve interacted with your app and added assertions, you can save your recording and generate the Espresso test. Click “Complete Recording”, enter the test class name, and click “Save”.
Running an Espresso Test Locally
Espresso tests can be run locally using the Project window in Android Studio. Open the desired app module folder and navigate to the test you want to run. Right-click on the test and click “Run ‘testName’”.
Running an Espresso Test with Firebase Test Lab for Android
Firebase Test Lab allows you to test your app in the cloud on various device configurations. To run Espresso tests with Firebase Test Lab, create a Firebase project for your app and follow the instructions to run your tests from Android Studio.
Espresso Test Android Cheat Sheet
Google provides a clear cheat sheet that testers can refer to while developing test cases with Espresso. The cheat sheet provides references to most of the instances that come with the Espresso Components.
Why Use Espresso Instead of Appium?
Both Espresso and Appium are test frameworks used for automation, but they differ in their applicability. While Appium assists with testing how well an app responds to various scenarios and manages different user flows, Espresso helps you test an Android app’s UI and UI component behaviour.
Running Espresso Tests on Real Devices
While testing, it is recommended for the SDETs and QA teams to run Espresso Tests on real devices and take real user conditions into account. A cloud-based real device tool like BrowserStack Automate provides access to all the latest and legacy real Android Devices to run your Automation tests and achieve accurate test results.
In summary, Android UI Tests with Espresso are an essential part of successful Android application development. The Espresso framework simplifies the process of UI testing, ensuring that your app delivers a top-notch user experience. So, leverage the power of Espresso and make your Android app testing more efficient and effective!