Flutter for Beginners

Writing unit tests

Now, let's suppose that we want to create a function that sums two numbers:

class Calculator {  num sumTwoNumbers(num a, num b) {     // TODO  }}

We can write a unit test to evaluate this method implementation by using the test package:

import 'package:test/test.dart';import 'package:unit_tests/calculator.dart';void main() {  Calculator calculator;  setUp(() {    calculator = Calculator();  });  test('calculator sumTwoNumbers() sum the both numbers', () {    expect(calculator.sumTwoNumbers(1, 2), 3);  });}

In the preceding example, we started by importing the test package main library that exposes functions, for example: setUp(), test(), and expect(). Each of the functions has specific roles, as follows:

• setUp() will execute the callback ...