Consider running `beforeEach` before nested `beforeAll`.

Feature Proposal

Change how beforeEach/beforeAll are ordered to respect nesting.

Motivation

Let’s say I have a test file like this

describe('example', () => {
  let someObject;

  beforeEach(() => {
    someObject = {someProperty: 'This is needed for a test or something.'}
  });

  it('test one', () => {})

  describe('nested', () => {
    let someOtherObject;

    beforeAll(() => {
      someOtherObject = doSomethingWith(someObject.someProperty);
    });

    it('test two', () => {
      expect(someOtherObject).toBeDefined();
    });
  });
});

I run it and everything passes. But, then I move/xit/comment out “test one”, and “test two” breaks, and it’s not immediately apparent why.

Example

// This should print "example.beforeEach" before "nested.beforeAll" instead of the other way around.
describe('example', () => {
  beforeEach(() => console.log('example.beforeEach'));

  describe('nested', () => {
    beforeAll(() => console.log('nested.beforeAll'));

    it('does something.', () => {});
  });
});

Pitch

It makes editing test suites more predictable.

[lackovic]

Should also make beforeEach execute only once before each block in its root scope - not before each test function contained in every sub-block. e.g.:

describe('root', () => {
  beforeAll(() => console.log('beforeAll root'));
  beforeEach(() => console.log('beforeEach root'));

  test('1', () => console.log('1'));

  describe('nested', () => {
    beforeAll(() => console.log('beforeAll nested'));
    beforeEach(() => console.log('beforeEach nested'));

    test('2', () => console.log('2'));
    test('3', () => console.log('3'));
  });
});

will print:

beforeAll root
beforeEach root
1
beforeEach root
beforeAll nested
beforeEach nested
2
beforeEach nested
3

which makes perfect sense to me.

[sgronblo]

Just wanted to say that I agree with most other commenters that the ordering should be based on the nesting. Inner before outer. Not that beforeAll’s must come before beforeEach. At least it’s shown in the documentation: https://jestjs.io/docs/en/setup-teardown, although it could be made more explicit.