Jest

Global Hooks Not Executed or Executed in Wrong Order

If you use Jest's global hooks like before*() and after*() that do no reside inside a describe-block you may run into the following issues:

• Hooks are not executed at all
• Hooks are executed in wrong order

The solution is to stop using global hooks and do your setup inside a describe-block. Please also consult Jest's docs for a detailed explanation.

/*
 * DO NOT DO THIS!
 */
beforeAll(() => console.log('1 - beforeAll')); // won't work reliably
afterAll(() => console.log('1 - afterAll')); // won't work reliably
beforeEach(() => console.log('1 - beforeEach')); // won't work reliably
afterEach(() => console.log('1 - afterEach')); // won't work reliably

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

/*
 * DO THIS INSTEAD
 */
describe('Scoped / Nested block', () => {
  beforeAll(() => console.log('2 - beforeAll')); // works
  afterAll(() => console.log('2 - afterAll')); // works
  beforeEach(() => console.log('2 - beforeEach')); // works
  afterEach(() => console.log('2 - afterEach')); // works

  it('', () => console.log('2 - test'));
  
  describe('More deeply scoped / nested block', () => {
    beforeAll(() => console.log('3 - beforeAll')); // works
    afterAll(() => console.log('3 - afterAll')); // works
    beforeEach(() => console.log('3 - beforeEach')); // works
    afterEach(() => console.log('3 - afterEach')); // works
  
    it('', () => console.log('3 - test'));
  });
});

Termination Error

Jest sometimes has problems terminating correctly. If this happens, you can see the following error message:

Jest did not exit one second after the test run has completed.

This usually means that there are asynchronous operations 
that weren't stopped in your tests. 
Consider running Jest with `--detectOpenHandles` to troubleshoot this issue.

As described in the error message Jest has problems stopping because of some processes which are still running. This can cause problems in your CI/CD pipeline because your pipeline can't continue after getting this error.

A solution is to force Jest to stop. For this case Jest provides the --forceExit flag:

npx jest --config ./test/jest.config.ts --forceExit