Flutter Mobile Development · Lesson

Unit Testing & Mocking

Write fast, isolated unit tests for your Flutter business logic and use mocks to test code that depends on services and APIs.

The Testing Pyramid

You have seen widget and integration tests. At the base sits the fastest layer: unit tests that verify a single function or class in isolation.

A unit test uses test() and expect() from the test package.

import 'package:test/test.dart';

void main() {
  test('adds two numbers', () {
    expect(2 + 3, equals(5));
  });
}