Jest

Naming Test

__tests__/*.js
*.spec.js
*.test.js

Example Test

Describe is the suite, it is the test

describe("The question list ", ()=> {
    it ("should display a list of items", ()=> {
        expect(2+2).toEqual(4);
    })

    it ("should display a list of items", ()=> {
        expect(2+4).toEqual(6);
    })

})

Setup and Teardown

This can be done using

BeforeEach BeforeAll

beforeAll(()=>{
   console.log("Hello");
});

and

AfterEach AfterAll

afterAll(()=>{
   console.log("Hello");
});

Note does not matter what order you write them in.

Skipping and Isolating Tests

Add keyword only to include tests

    it.only ("should display a list of items", ()=> {
        expect(2+2).toEqual(4);
    })

Add keyword skip to exlude tests

    it.skip ("should display a list of items", ()=> {
        expect(2+2).toEqual(4);
    })

Async Tests

it('async test 1', done=> {
    setTimeout(done, 100)
});

it('async test 2',()=> {
    return new Promise(
        resolve => setTimeout(resolve,100)
    );
});

it('async test 1', async ()=>
    await delay(100)
);