modify promise object using reducer react

To modify a Promise object using a reducer in React, you can follow these steps:

1. Create a reducer function that takes the current state and an action as parameters and returns a new state. The reducer should handle different actions to modify the Promise object.

const reducer = (state, action) => {
  switch (action.type) {
    case 'FULFILL':
      return {
        ...state,
        fulfilled: true,
        result: action.payload,
      };
    case 'REJECT':
      return {
        ...state,
        rejected: true,
        error: action.payload,
      };
    default:
      return state;
  }
};

2. Initialize the Promise object and its state using the useReducer hook.

const initialState = {
  fulfilled: false,
  rejected: false,
  result: null,
  error: null,
};

const [promiseState, dispatch] = useReducer(reducer, initialState);

const myPromise = new Promise((resolve, reject) => {
  // Perform asynchronous operation
  // Call resolve(result) or reject(error) based on the operation's outcome
});

3. Modify the Promise object based on the desired action using the dispatch function.

const handleFulfill = (result) => {
  dispatch({ type: 'FULFILL', payload: result });
};

const handleReject = (error) => {
  dispatch({ type: 'REJECT', payload: error });
};

myPromise.then(handleFulfill).catch(handleReject);

4. Access the modified Promise object's state using promiseState in your React component.

return (
  <div>
    {promiseState.fulfilled && <p>Promise fulfilled with result: {promiseState.result}</p>}
    {promiseState.rejected && <p>Error occurred: {promiseState.error}</p>}
  </div>
);

By using a reducer, you can easily manage the state of the Promise object and update it based on different actions in a predictable manner