Test coverage in Flutter - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the Flutter test package needed for writing tests.

Flutter

import '[1]';

void main() {
  test('Simple test', () {
    expect(1 + 1, 2);
  });
}

Drag options to blanks, or click blank then click option'

Apackage:flutter/widgets.dart

Bpackage:flutter/material.dart

Cpackage:flutter_test/flutter_test.dart

Dpackage:flutter/src/widgets/framework.dart

Attempts:

3 left

💡 Hint

Common Mistakes

Importing material.dart instead of flutter_test.dart

Forgetting to import any test package

The correct import for Flutter testing utilities is 'package:flutter_test/flutter_test.dart'.

2fill in blank

medium

Complete the code to define a widget test that checks if a Text widget displays the correct string.

Flutter

testWidgets('Check Text widget', (WidgetTester [1]) async {
  await tester.pumpWidget(const Text('Hello'));
  expect(find.text('Hello'), findsOneWidget);
});

Drag options to blanks, or click blank then click option'

Atester

Bwidget

Ccontext

DtesterWidget

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect parameter names like 'widget' or 'context'

Not using the WidgetTester parameter at all

The testWidgets function provides a WidgetTester object usually named 'tester' to interact with widgets.

3fill in blank

hard

Fix the error in the test code by completing the missing method to rebuild the widget tree after state changes.

Flutter

testWidgets('Tap button increments counter', (WidgetTester tester) async {
  await tester.pumpWidget(const MyCounterApp());
  await tester.tap(find.byIcon(Icons.add));
  await tester.[1]();
  expect(find.text('1'), findsOneWidget);
});

Drag options to blanks, or click blank then click option'

Apump

Btap

Cbuild

Drebuild

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'tap()' again instead of 'pump()'

Using non-existent methods like 'rebuild()'

After simulating a tap, calling 'pump()' rebuilds the widget tree to reflect changes.

4fill in blank

hard

Fill both blanks to create a test that verifies a widget is not found after an action.

Flutter

testWidgets('Verify widget disappears', (WidgetTester tester) async {
  await tester.pumpWidget(const MyWidget());
  await tester.tap(find.byKey(Key('removeButton')));
  await tester.[1]();
  expect(find.byType(Text), [2]);
});

Drag options to blanks, or click blank then click option'

Apump

BfindsNothing

CfindsOneWidget

Dtap

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'tap()' instead of 'pump()' after interaction

Using 'findsOneWidget' when expecting no widget

After tapping, 'pump()' rebuilds the UI, and 'findsNothing' checks that the widget is gone.

5fill in blank

hard

Fill all three blanks to write a test that pumps a widget, taps a button, and verifies the counter text updates.

Flutter

testWidgets('Counter increments test', (WidgetTester [1]) async {
  await [1].pumpWidget(const CounterApp());
  await [1].tap(find.byIcon(Icons.add));
  await [1].[2]();
  expect(find.text('[3]'), findsOneWidget);
});

Drag options to blanks, or click blank then click option'

Atester

Bpump

C1

Dtap

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong variable names instead of 'tester'

Forgetting to call 'pump()' after tap

Checking wrong text value

The WidgetTester is named 'tester'. After tapping, call 'pump()' to rebuild. The counter text should show '1'.