flutter test example

widget_test.dart

// This is a basic Flutter widget test.
//
// To perform an interaction with a widget in your test, use the WidgetTester
// utility that Flutter provides. For example, you can send tap and scroll
// gestures. You can also use WidgetTester to find child widgets in the widget
// tree, read text, and verify that the values of widget properties are correct.

import 'package:ahille/calculator_test.dart';
import 'package:ahille/home_page.dart';
import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';

import 'package:ahille/main.dart';

void main() {
  testWidgets('home page contains hello world text', (WidgetTester tester) async {
    final testWidget = MaterialApp(
      home: HomePage(),
    );

    await tester.pumpWidget(testWidget);
    await tester.pumpAndSettle();

    final buttonMaterial = find.descendant(
      of: find.byType(ElevatedButton),
      matching: find.byType(Material),
    );

    final materialButton = tester.widget<Material>(buttonMaterial);

    expect(materialButton.color, Colors.blue);
    expect(find.text('Weather today'), findsOneWidget);
    expect(find.byKey(const Key('icon_weather')), findsOneWidget);
  });

  testWidgets('Counter increments smoke test', (WidgetTester tester) async {
    // Build our app and trigger a frame.
    await tester.pumpWidget(const MyApp());

    // Verify that our counter starts at 0.
    expect(find.text('0'), findsOneWidget);
    expect(find.text('1'), findsNothing);

    // Tap the '+' icon and trigger a frame.
    await tester.tap(find.byIcon(Icons.add));
    await tester.pump();

    // Verify that our counter has incremented.
    expect(find.text('0'), findsNothing);
    expect(find.text('1'), findsOneWidget);
  });

  group('tests for add component', () {
    late Calculator calculator;

    setUp(() {
      calculator = Calculator();
    });

    test('should return a + b when a and b are two positives.', () {
      // arrange
      int a = 10;
      int b = 20;
      int expectedResult = a + b;

      // act
      int actualResult = calculator.add(a, b);

      // assert
      expect(actualResult, expectedResult);
    });

    test('should return a + b when a and b are two negatives.', () {
      // arrange
      int a = -10;
      int b = -20;
      int expectedResult = a + b;

      // act
      int actualResult = calculator.add(a, b);

      //assert
      expect(actualResult, expectedResult);
    });

    test('should return a + b when a is negative and b is positive', () {
      // arrange
      int a = -10;
      int b = 20;
      int expectedResult = a + b;

      // act
      int actualResult = calculator.add(a, b);

      //assert
      expect(actualResult, expectedResult);
    });

    test('should return a + b when a is positive and b is negative.', () {
      // arrange
      int a = -10;
      int b = -20;
      int expectedResult = a + b;

      // act
      int actualResult = calculator.add(a, b);

      //assert
      expect(actualResult, expectedResult);
    });    tearDown(() {
      // Nothing to do here.
    });
  });
}