Jest のDescribe, Before, Afterの実行順序

jestのdescribe, it, beforeEachの実行順序がよく分からなかったので確認した

version

jest: 23.1.0

まとめ

describeに書かれたコードが最初に実行される。
before, afterはitの実行前後に呼ばれるみたい。

確認

beforeAll(() => {
  console.log('outer before all')
})

beforeEach(() => {
  console.log('outer before each')
})

afterEach(() => {
  console.log('outer after each')
})

afterAll(() => {
  console.log('outer after all')
})

describe('some class', () => {
  console.log('describe some class')
  beforeAll(() => {
    console.log('inner before all')
  })

  beforeEach(() => {
    console.log('inner before each')
  })

  afterEach(() => {
    console.log('inner after each')
  })

  afterAll(() => {
    console.log('inner after all')
  })

  describe('some function', () => {
    console.log('describe some function')
    it('some expectation', () => {
      console.log('execute')
    })
  })
})

コンソール

 PASS  ./index.test.js
  some class
    some function
      √ some expectation (8ms)

  console.log index.test.js:18
    describe some class

  console.log index.test.js:36
    describe some function

  console.log index.test.js:2
    outer before all

  console.log index.test.js:20
    inner before all

  console.log index.test.js:6
    outer before each

  console.log index.test.js:24
    inner before each

  console.log index.test.js:38
    execute

  console.log index.test.js:28
    inner after each

  console.log index.test.js:10
    outer after each

  console.log index.test.js:32
    inner after all

  console.log index.test.js:14
    outer after all

Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   0 total
Time:        3.106s