Hey there!
As a veteran test automation specialist with over a decade‘s experience of running automated UI tests on thousands of real mobile devices, I‘m super excited to walk you through a complete guide on leveraging Appium to automate your Flutter app testing.
I‘ve helped numerous startups successfully shift-left and achieve faster release cycles by setting up smart test automation for their mobile apps. So let‘s get you started on the journey as well!
Why Appium for Testing Flutter Apps
As Flutter grows popular for building high-quality iOS and Android apps with faster development cycles, having an automation-first testing strategy right from the initial phases becomes critical.
And that‘s where Appium comes in.
Appium is an open-source test framework specialized for automation across native, hybrid and mobile web apps. Some awesome capabilities:
- Supports iOS, Android and Windows platforms
- Single API to write test scripts across platforms
- Automate testing of native, hybrid and web app views
- Easy integration with CI/CD pipelines
- Thriving ecosystem with rich documentation and extensions
The recently launched purpose-built Flutter Driver takes Appium‘s capabilities to the next level for testing Flutter apps. Itprovides exclusive automation support for Flutter framework elements like widgets, gestures, animations etc.
This gives your team a future-proof and full-stack automation solution to test Flutter apps with speed and confidence even as complexity increases over time.
Excited to get started? Let me walk you through the step-by-step journey…
Understanding Flutter App Architecture
Flutter apps are built using Google‘s Dart language and shipped with the Flutter runtime to execute on both Android and iOS platforms.
Here are some key aspects of Flutter application architecture:
- Flutter Engine – Rendering engine that draws the app UI and elements using Skia graphics library and Dart runtime.
- Foundation Library – Contains core framework packages like animation, widgets, etc.
- Widgets – Immutable declaration of UI elements. Apps are essentially widget trees.
- Material/Cupertino – Widget sets for Android and iOS design languages.
This architecture optimized for faster rendering and expressions allows building visual rich cross-platform apps with fluid performance.
Now let me show you how to build your first Flutter app…
Creating Your First Flutter App
We‘ll use Visual Studio Code as the IDE for this demo. Make sure to install the Flutter and Dart plugins for a smooth experience.
Fire up the terminal and enter:
flutter create my_app
cd my_app
flutter runThis swiftly sets up a simple webapp with some elemental widget scaffolding. Leave it running for now. We‘ll extend this into a modular demo app soon for automation testing!
Understanding Appium
Let‘s briefly contextualize key capabilities that make Appium such a versatile test automation framework.
The magic happens via the WebDriver protocol. Appium implements the protocol to communicate with platforms‘ native automation frameworks like XCUITest (iOS), UIAutomator2 (Android) etc.
As a test automation engineer, you simply use the Appium API in your scripts to replicate user actions via:
- Finding element locators
- Tapping buttons
- Sending text
- Swiping
- Validating screen states
Appium seamlessly translates these into platform-specific automation commands – allowing you to focus on writing tests without worrying about the underlying complexity!
Plus you get this "write once, run anywhere" ability out of the box!
Now let‘s shift gears and see the Appium Flutter Driver designed specifically for Flutter in action…
Setting up Appium Flutter Driver
The Appium Flutter Driver is an optional package that needs explicit installation:
npm install appium-flutter-driver This brings in the Flutter automation extension along with a finder library to efficiently locate widgets.
While starting the Appium server, we need to specify automationName capability:
// Config for Android
caps.platformName = ‘Android‘;
caps.automationName = ‘Flutter‘;This activates the Flutter Driver. We also get built-in utilities like:
driver.execute(‘flutter:checkHealth‘); To check connectivity status and debug issues.
Okay, we are all set to begin automation for Flutter!
Inspecting Flutter App Elements
The Flutter Driver finder module contains semantic locator builders to detect widgets efficiently without brittle selectors:
// Find by text
find.text(‘Login‘)
// Find by value key attribute
find.byValueKey(‘submit_btn‘)
// Find by runtimeType
find.byType(‘ElevatedButton‘)Using properties like valueKey helps create reliable selectors impervious to text changes.
Now let‘s augment our demo app specifically for test automation convenience…
Preparing Flutter App for Automation
Let‘s build out the demo app into a modular structure with login functionality having valueKey identifiers:
main.dart
|- login_page.dart
|- login_form.dart
|- home_page.dartHere is how the login form looks with valueKey attributes:
TextFormField(
key: ValueKey(‘email_input‘),
decoration: InputDecoration(labelText: ‘Email‘),
);
TextFormField(
key: ValueKey(‘password_input‘),
obscureText: true,
decoration: InputDecoration(labelText: ‘Password‘),
);
ElevatedButton(
key: ValueKey(‘login_button‘),
onPressed: _loginUser,
child: Text(‘Login‘),
);This gives us semantic locators to uniquely identify UI elements for writing automation scripts.
Writing Flutter Appium Test Automation Script
Let‘s design some test automation flows through the app:
Happy Path:
- Valid credentials provided
- Verify home page displayed
Negative Scenario:
- Invalid credentials provided
- Verify error message displayed
Edge Case:
- Keep fields empty
- Verify error messaging
Here is how the test automation script outlines:
// Launch Flutter driver
driver = initialiseDriver();
// Test 1: Valid credentials
enterText(find.byValueKey(‘email_input‘), ‘[email protected]‘);
enterText(find.byValueKey(‘password_input‘), ‘p@ssw0rd‘);
tap(find.byValueKey(‘login_button‘));
assertPageLoaded(‘HomeScreen‘);
// Test 2: Invalid credentials
enterText(find.byValueKey(‘email_input‘), ‘[email protected]‘);
enterText(find.byValueKey(‘password_input‘), ‘wrongPassword‘);
tap(find.byValueKey(‘login_button‘));
assertVisible(find.text(‘Invalid credentials‘));
// Test 3: Empty credentials
tap(find.byValueKey(‘login_button‘));
assertVisible(find.text(‘Please enter email and password‘));
The reusable test building blocks can be organized into:
- Methods to perform actions like enterText(), tap()
- Utility assertions like assertPageLoaded(), assertVisible()
- Easy parametrization for test data
As you enhance the app with more features, composing new test flows using these building blocks becomes super productive!
This structure forms the basis of scalable test automation.
But for confidence in real world behavior – we need to execute on real devices…
Executing Tests on Real Mobile Devices
While emulators allow quick validation, testing apps on real devices across various OS versions is vital for success, especially for platforms like Flutter that compile into native code.
Manually acquiring and maintaining a large inventory of devices is extremely challenging and expensive.
This is where cloud testing platforms like BrowserStack come into the picture. BrowserStack provides instant access to thousands of popular real Android and iOS devices hosted on their secure cloud infrastructure.
We simply upload the Flutter app and test scripts to trigger automated Appium based test executions. The platform takes care of parallelizing tests across different mobile brands, OS versions and screen sizes.
Advanced debugging allows interacting with the app during test run to investigate issues. Detailed reports provide insights into failures and performance.
BrowserStack seamlessly integrates with CI/CD pipelines as well – helping shift app testing left and prevent regressions from escaping to users.
Key Takeaways
Let me summarize the key pointers from this guide to help you in your test automation journey with Appium:
- Appium provides a versatile way to automate UX testing for native, hybrid and mobile web apps with a single framework
- The Flutter Driver extension brings native support for automating Flutter app testing
- Follow Appium best practices like using semantic locators for reliable element detection
- Structure your test suite using reusable actions and assertions
- Cloud testing platforms help run automation suites across an extensive matrix of real devices
Automated testing is key to accelerate Flutter app delivery along with confidence of quality. I hope you found this detailed hands-on guide useful. Share your feedback or any questions you may have!
Happy testing!
