How to run jest unit tests with ES6 modules in Node.js

Recently one of my VueJS side projects, I have used jest to do unit testing and I must say I really like the simplicity of it.

More over, it is blazing fast with parrell execution and runs only the changed specs on watch mode.

Jest in NodeJS#

In order to start with jest, let's first install it by the following:

$ npm i jest

After the successful installation, configure your package.json as below to run unit specs:

"scripts": {
  "test": "jest"
}

Yes, its that simple! \O/

Jest magic#

When we run jest script, it just starts to look for files ending with spec.js from the running directory and starts executing them.

A sample of the unit is below:

describe('App.vue', () => {
	it('should render with app banner', () => {
		const wrapper = shallowMount(App)
		const banner = wrapper.find('.banner')

		expect(banner.isVisible()).toBeTruthy()
		expect(banner.find('.display-3').text())
				.toMatch(/iTunes Album Finder/)
		expect(banner.find('.lead').text()).toMatch(
				/One stop for all your favourite artist's albums/
		)
	})
})

If you are familiar with jasmine, then this should not be a surprise to you. ^_^