forkTakeEvery.js

function* before() {
  yield fork(function*() {
    yield* takeEvery('FETCH_USERS', fetchUsers)
  })
  yield fork(function*() {
    yield* takeEvery('CREATE_USER', createUser)
  })
}
function* after() {
  yield fork(takeEvery, 'FETCH_USERS', fetchUsers)
  yield fork(takeEvery, 'CREATE_USER', createUser)
}