CODEWITHSUNDEEP
node.jsmocha.js
TheLukeMcCarthy
TheLukeMcCarthy

Reputation: 2283

Mocha runs nested beforeEach in unexpect order

I have a test suite using Mocha with nested describe and beforeEach blocks. When I run the tests I expect the outer beforeEach to run before the inner beforeEach

Here is some sample code

const expect = require('chai').expect

describe('Outer describe', async () => {
  beforeEach(() => {
    console.log('Outer beforeEach is running!!!!');
  });

  afterEach(() => {
    console.log('Outer afterEach is running!!!!');
  });

  it('Outter test', async () => {
    expect(true).to.be.true;
  });

  describe('Inner describe', () => {
    before(() => {
      console.log('Inner beforeEach is running!!!!');
    });

    after(() => {
      console.log('Inner afterEach is running!!!!');
    });

    // only used to simplify the output
    it.only('Inner test', async () => {
      expect(true).to.be.true;
    });
  })
});

He is the output from running the above tests

  Outer describe
    Inner describe
Inner beforeEach is running!!!!
Outer beforeEach is running!!!!
      ✓ Inner test
Outer afterEach is running!!!!
Inner afterEach is running!!!!

What I was expecting was

  Outer describe
    Inner describe
Outer beforeEach is running!!!!
Inner beforeEach is running!!!!
      ✓ Inner test
Inner afterEach is running!!!!
Outer afterEach is running!!!!

Is this expected behaviour? My inner beforeEach depends on my outer beforeEach running before it, is this considered bad practice?

I'm using
Node 14.11.0
Mocha 8.1.3

Upvotes: 1

Views: 1317

Answers (1)

TheLukeMcCarthy
TheLukeMcCarthy

Reputation: 2283

The reason the output is not as expected is the inner describe is using a before instead of beforeEach

before only runs once before all tests in the describe block and beforeEach runs before every test in the describe block. This means the outer describe's beforeEach needs to run after the inner before

Upvotes: 1

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