Service dependency for MobX State Tree

Service.js

import axios, { get, CancelToken } from 'axios'
import faker from 'faker'

//
// Only data property will be returned from the reuquest. This will simplify
// data processing, as it won't be neccesary to call .then() each time
// to return the request.data.
// See: https://github.com/axios/axios#response-schema
//
// The status codes validation, if needed, should be done in 'validateStatus'
// method of the Request config.
// See: https://github.com/axios/axios#request-config
//
axios.interceptors.response.use(({data}) => data)

//
// Request cancellation setup.
// See: https://github.com/axios/axios#cancellation
//
const CancelSource = CancelToken.source()

//
// Axios default configuration.
// See: https://github.com/axios/axios#request-config
//
const Options = headers => ({
  mode: 'cors',
  headers,
  // withCredentials: true,
  // credentials: 'same-origin',
  timeout: 3000,
  validateStatus: function (status) {
    return status >= 200 && status < 300; // default
  },
})

// Config for endpoint that is accepting and returning only text.
const configText = Options({
  'Content-Type': 'text/plain;charset=UTF-8',
  'Accept': 'text/plain',
})

// // Config for endpoint that is accepting and returning only json.
const configJson = Options({
  'Content-Type': 'application/json;charset=UTF-8',
  'Accept': 'application/json',
})

// REST services Address book.
// const Address = {
//   TEST: 'http://api.test.org',
// }
//
// const { TEST } = Address

// Fake request delay.
const Delay = time => new Promise(resolve => setTimeout(() => resolve(), time))

const Service = {
  // Fake data generated by Faker.js.
  fake: {
    getAddress: async function () {
      try {
        return await Delay(500).then(data => {
          return Array.from({length: 10}, (v, k) => ({
            id: k,
            email: faker.internet.email(),
            image: faker.image.imageUrl(),
            descr: faker.lorem.paragraph(),
            uuid: faker.random.uuid()
          }))
        })
      } catch (error) {
        throw new Error(`Fake API getAddress: ${error.message}`)
      }
    },
  },
  // Testing different functions and custom requests.
  test: {
    test: async function (url, defaultConfig = configText || configJson) {
      // Example of a config for cancelable request.
      const config = {...defaultConfig, cancelToken: CancelSource.token}

      try {
        return await get(url, config)
      } catch (error) {
        // Custom Error handling.
        if (error.response) {
          throw new Error(`Status code out of valid range: ${error.message}`)
        } else if (error.request) {
          throw new Error(`The request was made, but no response was received.`)
        } else {
          throw new Error(`Request triggered an Error: ${error.message}`)
        }
      }
    },
  }
}

export default Service