Basic Generator Function for Asynchronous Flows

Demonstrate the creation of a simple generator function to manage asynchronous flows, yielding promises and managing their resolution within a Redux-Saga context.

function* fetchUserData() {
  // Using yield to wait for the promise to resolve
  const user = yield fetch('https://api.example.com/user').then(res => res.json());
  return user;
}

This generator function fetchUserData uses yield to pause execution until the fetch promise resolves, effectively managing an asynchronous flow.

function* mainSaga() {
  // Wait for a specific action to dispatch
  yield take('FETCH_USER_REQUEST');
  // Call fetchUserData and wait for it to finish
  const userData = yield call(fetchUserData);
  // Dispatch an action with the result of the fetch
  yield put({ type: 'FETCH_USER_SUCCESS', payload: userData });
}

mainSaga waits for a 'FETCH_USER_REQUEST' action, then processes the asynchronous fetchUserData generator function, and finally dispatches the success action with the fetched data.