Reducer utility

01_createReducer.js

export (reducerMap, initialState) => (state = initialState, action) => {
  const reducer = reducerMap[action.type];
  return reducer ? reducer(state, action) : state;
}

transactions.js

import createReducer from '../utilities/createReducer';
import * as types from '../constants/TransactionTypes';

export const initialState = {
  $isLoading: false,
  $didFailFetching: false,
  $didLoad: false,
  userId: null,
  transactions: [],
  entities: {
    transactions: {}
  }
};

export default createReducer({
  [types.REQUEST_TRANSACTIONS]: (state, action) => ({
    ...state,
    $isLoading: true
  }),
  [types.FAILURE_TRANSACTIONS]: (state, action) => ({
    ...state,
    $isLoading: false,
    $didFailFetching: true
  }),
  [types.RECEIVE_TRANSACTIONS]: (state, { data: { transactions, user } }) => ({
    ...state,
    userId: (user && user.id || null),
    $isLoading: false,
    $didLoad: true,
    transactions: union(pluck(transactions, 'subid'), state.transactions),
    entities: {
      transactions: merge({}, state.entities.transactions, indexBy(transactions, 'subid'))
    }
  })
}, initialState);