Testing and Debugging

As a senior engineer with a background in Java backend development, you're already familiar with the importance of testing and debugging. In frontend development, testing and debugging are equally crucial for building production-ready apps.

When it comes to testing frontend code, one common approach is using the Jest testing framework. Jest provides a simple and intuitive API for writing tests, making it popular among frontend developers.

Here's an example of a unit test using Jest to validate addition:

1// Testing with Jest
2
3test('Adding two numbers', () => {
4  expect(2 + 2).toBe(4);
5});

In addition to testing, debugging frontend code is vital for identifying and fixing issues. A common technique for debugging is using the console.log() function.

Here's an example of using console.log() to output a greeting:

1// Debugging with console.log()
2
3const greeting = 'Hello, World!';
4console.log(greeting);

xxxxxxxxxx

// Debugging with console.log()

​

const greeting = 'Hello, World!';

console.log(greeting);

​

// Testing with Jest

​

test('Adding two numbers', () => {

  expect(2 + 2).toBe(4);

});