Of Redux Thunk, Sequelize (Bluebird) - returning promise to action creator "chain"

Question

So similar to some previous posts referenced below, I'm trying to chain dispatch through Thunk, however my difficulty is on the return from Sequelize. I can see the MySQL query hit the DB and return data, however that return is not flowing through the action-creator to the subsequent .then

I presume it's the manner in which I'm trying to use Sequelize - I'm new to it.

Many thanks!

Code:

initDB.js

...
export function sequelizeQry(qryName: string) {
  let query;

  // For later query mapping
  switch (qryName) {
    case 'POSummary':
      query = qry.spPOLedgerCardSummaryALL;
      break;
    default:
      query = qry.spPOLedgerCardSummaryALL;
  }

  return new sequelize.Promise(
    () => sequelize.query(query, { type: sequelize.QueryTypes.RAW })
      .then((response) => {
        console.log('Returning promise: ', response);        //<-- This hits the console with data
        return response;
      })
  );
}

database-actions.js

// @flow
import { fetchingQuery } from '../action-creators/database-creators';

const fetchQuery = (qryName: string) =>
  (dispatch: *) => dispatch(fetchingQuery(qryName));

export default fetchQuery;

database-creators.js

// @flow
// Action Types
import { FETCH_QUERY } from '../constants/ActionTypes';
import { sequelizeQry } from '../utils/initDB';

/** Action-creators */
export function fetchingQuery(qryName: string) {
  const actionType = FETCH_QUERY;

  return (dispatch: *) => {
    dispatch({ type: `${actionType}_PENDING` });
    sequelizeQry(qryName)                          //<-- This gets called
      .then((payload) => dispatch({                //<-- Don't seem to get here
        type: `${actionType}_FULFILLED`,
        payload
      }))
      .catch(err =>
        // Dispatch the error action with error information
        dispatch({
          type: `${actionType}_REJECTED`,
          error: err
        })
      );
  };
}

Some other references I've checked:

Is `sequelize.Promise` a standard promise? If so, you need to pass `resolve` as a parameter to the promise executor/handler, and then call `resolve(response)` instead of `return response`. — adrice727, Jun 12 '17 at 19:16
It looks like that was it, thank you so much. FLOW was nagging about requiring a `return` in a `.then` and I stopped thinking ... much appreciated! — Mark, Jun 12 '17 at 19:24
Actually `return resolve(response)` makes FLOW happy ... I updated the below. Thanks again. — Mark, Jun 12 '17 at 20:36

Mark · Accepted Answer · 2017-06-12T20:35:20.710

All credit goes to adrice727.

Here's the code change for future visitors:

...
  return new sequelize.Promise(
    () => sequelize.query(query, { type: sequelize.QueryTypes.RAW })
      .then((response) => {
        console.log('Returning promise: ', response);        //<-- This hits the console with data
        return response;
      })
  );
...

// BECOMES

return new sequelize.Promise(
    (resolve) => sequelize.query(query, { type: sequelize.QueryTypes.RAW })
      .then((response) => {
        console.log('Returning promise: ', response);
        return resolve(response);
      })
  );

Of Redux Thunk, Sequelize (Bluebird) - returning promise to action creator "chain"

1 Answers1