Understanding mocha's nested before and after hooks

mocha.spec.ts

'use strict';

describe('mocha before and after hooks', function () {
  before(() => console.log('*** top-level before()'))
  beforeEach(() => console.log('*** top-level beforeEach()'))
  after(() => console.log('*** top-level after()'))
  afterEach(() => console.log('*** top-level afterEach()'))
  describe('nesting', function () {
    before(() => console.log('*** nested before()'))
    beforeEach(() => console.log('*** nested beforeEach()'))
    after(() => console.log('*** nested after()'))
    afterEach(() => console.log('*** nested afterEach()'))
    it('is a nested spec 1', () => console.log('nested spec 1'))
    it('is a nested spec 2', () => console.log('nested spec 2'))
  })
})

// *** top-level before()
// *** nested before()
// *** top-level beforeEach()
// *** nested beforeEach()
// nested spec 1
// *** nested afterEach()
// *** top-level afterEach()
// *** top-level beforeEach()
// *** nested beforeEach()
// nested spec 2
// *** nested afterEach()
// *** top-level afterEach()
// *** nested after()
// *** top-level after()

Inspired by https://gist.github.com/harto/c97d2fc9d0bfaf20706eb2acbf48c908 with added after and afterEach