React Native Redux : "Undefined is not an object (evaluating 'action.type')"

Question

I'm use Redux with ReactNative,I'd like to create a store with reducer

And,I got error below, point to line 'switch (action.type)' in function toggleFavorite() in favoriteReducer.js. I found a similar topic but it didn't fix it...

undefined is not an object(evaluating 'action.type')

favoriteReducer.js :

const initialState = { favoriteQuotes: [] }

function toggleFavorite(state = initialState, action) {
  let nextState
  switch (action.type) {
    case 'TOGGLE_FAVORITE':
      const favoriteQuoteIndex = state.favoriteQuotes.findIndex(item => item.id === action.value.id)
      if (favoriteQuoteIndex !== -1) {
        // La citation est déjà dans les favoris, on la supprime de la liste
        nextState = {
          ...state,
          favoriteQuotes: state.favoriteQuotes.filter( (item, index) => index !== favoriteQuoteIndex)
        }
      }
      else {
        // La citation n'est pas dans les favoris, on l'ajoute à la liste
        nextState = {
          ...state,
          favoriteQuotes: [...state.favoriteQuotes, action.value]
        }
      }
      return nextState || state
  default:
    return state
  }
}

export default toggleFavorite()

configureStore.js :

import { createStore } from 'redux';
import toggleFavorite from './Reducers/favoriteReducer'

export default createStore(toggleFavorite)

Here is where I use "dispatch":

import React from 'react'
...
import { connect } from 'react-redux'

class QuoteDetail extends React.Component {

...

  _toggleFavorite() {
    const action = { type: "TOGGLE_FAVORITE", value: this.state.quote }
    this.props.dispatch(action)
  }

...

<Button title="Favoris" onPress={() => this._toggleFavorite()}/>

...

const mapStateToProps = (state) => {
  return {
    favoriteQuotes: state.favoriteQuotes
  }
}
export default connect(mapStateToProps)(QuoteDetail)

Anyone have an idea ??

Shubham Khatri Shubham Khatri · Accepted Answer · 2019-02-09T14:35:02

You don't need to call the function while exporting, which is causing the error in your case, change it to

export default toggleFavorite;

and it will work

React Native Redux : "Undefined is not an object (evaluating 'action.type')"

1 Answers