Jest run async function ONCE before all tests

Question

This feature was added in Jest’s 22 version, with globalSetup and globalTeardown configurations.
Look at this for examples.

_{package.json (or in jest.config.js)}

{
  ...
  "jest": {
    "globalSetup": "./scripts/jestGlobalSetup.js"
  }
}

_{/scripts/jestGlobalSetup.js}

module.exports = async () => {
  console.log('\nhello, this is just before tests start running');
};

OR

export default async () => {
  console.log('\nhello, this is just before tests start running');
};