Patrol Writing Your First Patrol Test Case Estimated reading: 3 minutes 122 views Patrol is an excellent tool for automating Flutter app tests, ensuring that essential app functionalities work as expected across various devices. In this guide, we will walk through writing your first Patrol test, specifically focusing on a common user journey: signing into an app.Setting Up Your Patrol TestBefore diving into the test, ensure that you have Patrol properly installed in your project. With everything in place, let’s begin by writing a test that checks the functionality of a basic sign-in screen. Welcome Screen Sign In ScreenThe sign-in screen typically includes email and password input fields, followed by a sign-in button. Our goal in this Patrol test is to automate the process of entering the email and password, tapping the sign-in button, and verifying the navigation to the dashboard screen.The test begins with a basic import of necessary packages, such as flutter_test for testing utilities and patrol for test automation:Dartimport 'package:flutter/material.dart'; import 'package:flutter_test/flutter_test.dart'; import 'package:patrol/patrol.dart'; import 'package:richpay_app/main.dart' as app;By importing these packages, you set up a testing environment that allows you to interact with the app’s widgets during test execution.Structuring the Patrol TestNext, we define our Patrol test. In this example, we are testing the sign-in process by creating a test that verifies the email input, password input, and sign-in button functionality:Dartvoid main() { patrolTest( 'Sign In Screen - Verifies email input, password input, and sign-in button', ($) async { // Start the app app.main(); await $.pumpAndTrySettle();The patrolTest function defines a specific test case, and inside the function, we start the app using app.main(). This ensures that your app runs in the testing environment, ready to simulate user interactions.Interacting with WidgetsAfter starting the app, we simulate a tap on the sign-in button that appears on the welcome screen. We use the find.byKey method to locate the button using its unique Key:Dartfinal welcomeSignInButton = $(find.byKey(const Key('sign_in_btn'))); await $(welcomeSignInButton).tap(); await $.pumpAndSettle();The $(find.byKey()) function finds the button, and tap() simulates the user pressing it. The pumpAndSettle() method ensures that the app has finished rendering and settles before the next step. Widget Inspector Sign In ButtonEntering Text into Input FieldsNow, let’s verify and interact with the email and password input fields. We first locate the input fields using their respective keys and then simulate entering text:Dartfinal emailTextBox = $(find.byKey(const Key('email_username'))); await $(emailTextBox).enterText('test@gmail.com'); final passwordTextBox = $(find.byKey(const Key('password'))); await $(passwordTextBox).enterText('test123');The enterText() function is essential in automating user input for testing login forms, ensuring that valid text is entered into the relevant fields during the test. Widget Inspector Email & PasswordFinalizing the Test by Tapping the Sign-In ButtonAfter entering the login credentials, we locate and tap the sign-in button to submit the form:Dartfinal signInSignInButton = $(find.byKey(const Key('sign_in_btn'))); await $(signInSignInButton).tap(); // Wait for the navigation to complete after sign-in await $.pumpAndSettle(); Just like before, we use find.byKey to locate the sign-in button and simulate the tap. The app is given time to navigate by calling pumpAndSettle() to ensure all animations and transitions are complete before continuing. Widget Inspector Sign In ButtonVerifying the DashboardFinally, after the sign-in process completes, we want to verify that the user has successfully navigated to the dashboard. We can do this by checking if a specific widget or text related to the dashboard is visible: Widget Inspector Verify Dashboard TextDartexpect(find.text('Dashboard'),findsOneWidget); In this case, we check if the text Dashboard is displayed, confirming that the sign-in was successful and the user has reached the dashboard screen.ConclusionIn the next guide, we’ll dive deeper into Organizing Test Suites in Patrol, helping you structure your tests efficiently for larger applications. Stay tuned for more best practices and techniques to optimize your mobile testing process with Patrol!Tagged:Patrol Patrol - Previous Setting Up Patrol Test Next - Patrol Organizing Test Suites in Patrol