Function _addHook

packages/jest-circus/src/index.ts:93–109

(
  fn: Circus.HookFn,
  hookType: Circus.HookType,
  hookFn: THook,
  timeout?: number,
)

};

const _addHook = (
  fn: Circus.HookFn,
  hookType: Circus.HookType,
  hookFn: THook,
  timeout?: number,
) => {
  const asyncError = new ErrorWithStack(undefined, hookFn);

  if (typeof fn !== 'function') {
    asyncError.message =
      'Invalid first argument. It must be a callback function.';

    throw asyncError;
  }

  dispatchSync({asyncError, fn, hookType, name: 'add_hook', timeout});
};

// Hooks have to pass themselves to the HOF in order for us to trim stack traces.
const beforeEach: THook = (fn, timeout) =>