[React] Axios Instance Example

instance.js

import { Alert } from 'react-native'

import axios from 'axios'

import SocketService from './socket'

import store, { actions } from '../store'

import config from '../config'

const instance = axios.create({ baseURL: `${config.API_URL}/api` })

instance.interceptors.request.use(handleSuccess, null)
instance.interceptors.response.use(null, handleError)

function handleSuccess (res) {
    if (res.url.includes('login') || res.url.includes('register')) return res

    const currentToken = store.getState().authentication.currentToken

    if (currentToken !== null) res.headers['Authorization'] = `Bearer ${currentToken.access_token}`

    const socket = SocketService.getSocket()

    if (socket !== null) res.headers['X-Socket-Id'] = socket.socketId()

    return res
}

function handleError (err) {
    let text = 'Ooops! \n Something went wrong.'

    const { response } = err

    if (response) {
        const { data, statusText } = response
        const { message, errors } = data

        if (errors && Object.entries(errors).length !== 0 && errors.constructor === Object) {
            const messages = []

            Object.keys(errors).forEach((key) => {
                errors[key].forEach((error) => {
                    messages.push(error)
                })
            })

            if (messages.length) {
                text = messages.join('\n\n')
            }
        } else {
            text = message ? message : statusText
        }
    }

    Alert.alert(null, text)

    if (err.response.status === 401) {
        store.dispatch(actions.authenticationActions.logout())
    }

    return Promise.reject(err)
}

export default axiosInstance