Learning Redux

Scoping

By default, the before and after functions apply to every test in a file. However, Jest also provides a way to group tests, via describe:

let posts = []beforeAll(() => {  posts.push({ title: 'test', user: 'dan' })  posts.push({ title: 'hello world', user: 'dan' })})test('test post exists', () =>  expect(posts).toContain({ title: 'test' }))describe('resolving users for posts', () => {  let users = []  beforeAll(() => {    users.push({ username: 'dan', realname: 'Daniel Bugl' })  })  test('getting realname of author', () =>    expect(getAuthorRealname(posts[0])).toMatch('Daniel Bugl')  )})

In the preceding example, the second beforeAll function only gets called for the tests in the describe block.