ErEduGilMor/redux/actions/index.js

import { USER_STATE_CHANGE } from '../constants/index'
import firebase from 'firebase'

export function fetchUser(){
    return((dispatch) => {
        firebase.firestore()
        .collection("Users")
        .doc(firebase.auth().currentUser.uid)
        .get()
        .then((snapshot) => {
            if(snapshot.exists){
                dispatch({type : USER_STATE_CHANGE, currentUser : snapshot.data()})
            }
            else{
                console.log('Does not exist')
            }
        })
    })
}