Migrating from flutter_driver
This page describes how to migrate an existing project using flutter_driver
to the integration_test
package, in order to run integration tests.
Tests with integration_test
use the same methods that are used in widget testing.
For an introduction to the integration_test
package, check out the Integration testing guide.
Starter example project
#The project in this guide is a small example desktop application with this functionality:
- On the left, there's a list of plants that the user can scroll, tap and select.
- On the right, there's a details screen that displays the plant name and species.
- On app start, when no plant is selected, a text asking the user to select a plant is displayed
- The list of plants is loaded from a local JSON file located in the
/assets
folder.
You can find the full code example in the Example Project folder.
Existing tests
#The project contains the three flutter_driver
tests performing the following checks:
- Verifying the initial status of the app.
- Selecting the first item on the list of plants.
- Scrolling and selecting the last item on the list of plants.
The tests are contained in the test_driver
folder, inside the main_test.dart
file.
In this folder there's also a file named main.dart
, which contains a call to the method enableFlutterDriverExtension()
. This file won't be necessary anymore when using integration_test
.
Setup
#To start using the integration_test
package, add the integration_test
to your pubspec.yaml
file if you haven't yet:
dev_dependencies:
integration_test:
sdk: flutter
Next, in your project, create a new directory integration_test/
, create your tests files there with the format: <name>_test.dart
.
Test migration
#This section contains different examples on how to migrate existing flutter_driver
tests to integration_test
tests.
Example: Verifying a widget is displayed
#When the app starts the screen on the right displays a text asking the user to select one of the plants on the list.
This test verifies that the text is displayed.
flutter_driver
In flutter_driver
, the test uses waitFor
, which waits until the finder
can locate the widget. The test fail if the widget can't be found.
test('do not select any item, verify please select text is displayed',
() async {
// Wait for 'please select' text is displayed
await driver.waitFor(find.text('Please select a plant from the list.'));
});
integration_test
In integration_test
you have to perform two steps:
First load the main app widget using the
tester.pumpWidget
method.Then, use
expect
with the matcherfindsOneWidget
to verify that the widget is displayed.
testWidgets('do not select any item, verify please select text is displayed',
(tester) async {
// load the PlantsApp widget
await tester.pumpWidget(const PlantsApp());
// wait for data to load
await tester.pumpAndSettle();
// Find widget with 'please select'
final finder = find.text('Please select a plant from the list.');
// Check if widget is displayed
expect(finder, findsOneWidget);
});
Example: Tap actions
#This test performs a tap action on the first item on the list, which is a ListTile
with the text "Alder".
After the tap, the test waits for the details to appear. In this case, it waits for the widget with the text "Alnus" to be displayed.
Also , the test verifies that the text "Please select a plant from the list." is no longer displayed.
flutter_driver
In flutter_driver
, use the driver.tap
method to perform a tap over a widget using a finder.
To verify that a widget is not displayed, use the waitForAbsent
method.
test('tap on the first item (Alder), verify selected', () async {
// find the item by text
final item = find.text('Alder');
// Wait for the list item to appear.
await driver.waitFor(item);
// Emulate a tap on the tile item.
await driver.tap(item);
// Wait for species name to be displayed
await driver.waitFor(find.text('Alnus'));
// 'please select' text should not be displayed
await driver
.waitForAbsent(find.text('Please select a plant from the list.'));
});
integration_test
In integration_test
, use tester.tap
to perform the tap actions.
After the tap action, you must call to tester.pumpAndSettle
to wait until the action has finished, and all the UI changes have happened.
To verify that a widget is not displayed, use the same expect
function with the findsNothing
matcher.
testWidgets('tap on the first item (Alder), verify selected', (tester) async {
await tester.pumpWidget(const PlantsApp());
// wait for data to load
await tester.pumpAndSettle();
// find the item by text
final item = find.text('Alder');
// assert item is found
expect(item, findsOneWidget);
// Emulate a tap on the tile item.
await tester.tap(item);
await tester.pumpAndSettle();
// Species name should be displayed
expect(find.text('Alnus'), findsOneWidget);
// 'please select' text should not be displayed
expect(find.text('Please select a plant from the list.'), findsNothing);
});
Example: Scrolling
#This test is similar to the previous test, but it scrolls down and taps the last item instead.
flutter_driver
To scroll down with flutter_driver
, use the driver.scroll
method.
You must provide the widget to perform the scrolling action, as well as a duration for the scroll.
You also have to provide the total offset for the scrolling action.
test('scroll, tap on the last item (Zedoary), verify selected', () async {
// find the list of plants, by Key
final listFinder = find.byValueKey('listOfPlants');
// Scroll to the last position of the list
// a -100,000 pixels is enough to reach the bottom of the list
await driver.scroll(
listFinder,
0,
-100000,
const Duration(milliseconds: 500),
);
// find the item by text
final item = find.text('Zedoary');
// Wait for the list item to appear.
await driver.waitFor(item);
// Emulate a tap on the tile item.
await driver.tap(item);
// Wait for species name to be displayed
await driver.waitFor(find.text('Curcuma zedoaria'));
// 'please select' text should not be displayed
await driver
.waitForAbsent(find.text('Please select a plant from the list.'));
});
integration_test
With integration_test
, can use the method tester.scrollUntilVisible
.
Instead of providing the widget to scroll, provide the item that you're searching for. In this case, you're searching for the item with the text "Zedoary", which is the last item on the list.
The method searches for any Scrollable
widget and performs the scrolling action using the given offset. The action repeats until the item is visible.
testWidgets('scroll, tap on the last item (Zedoary), verify selected',
(tester) async {
await tester.pumpWidget(const PlantsApp());
// wait for data to load
await tester.pumpAndSettle();
// find the item by text
final item = find.text('Zedoary');
// finds Scrollable widget and scrolls until item is visible
// a 100,000 pixels is enough to reach the bottom of the list
await tester.scrollUntilVisible(
item,
100000,
);
// assert item is found
expect(item, findsOneWidget);
// Emulate a tap on the tile item.
await tester.tap(item);
await tester.pumpAndSettle();
// Wait for species name to be displayed
expect(find.text('Curcuma zedoaria'), findsOneWidget);
// 'please select' text should not be displayed
expect(find.text('Please select a plant from the list.'), findsNothing);
});
Unless stated otherwise, the documentation on this site reflects the latest stable version of Flutter. Page last updated on 2024-05-03. View source or report an issue.