Redux Promise Middleware - Auto suffix the actions with: `_PENDING`, `_FULFILLED` and `_REJECTED`

actionTypes.js

/**
 * This method auto add to a list of actions the suffixes
 * provided by `redux-promise-middleware`.
 *
 * Example:
 *
 * export default createActionTypes(['GET_USER', 'CREATE_USER'])
 *
 * [object Object] {
 *   CREATE_USER: "CREATE_USER",
 *   CREATE_USER_FULFILLED: "CREATE_USER_FULFILLED",
 *   CREATE_USER_PENDING: "CREATE_USER_PENDING",
 *   CREATE_USER_REJECTED: "CREATE_USER_REJECTED",
 *
 *   GET_USER: "GET_USER",
 *   GET_USER_FULFILLED: "GET_USER_FULFILLED",
 *   GET_USER_PENDING: "GET_USER_PENDING",
 *   GET_USER_REJECTED: "GET_USER_REJECTED"
 * }
 */

const defaultSuffixes = ['', '_PENDING', '_FULFILLED', '_REJECTED']

const createActionTypes = (actions, suffixes = defaultSuffixes) => {
  const addSuffixes = action => (
    suffixes.reduce((acc, suffix) => {
      const name = `${action}${suffix}`
      acc[name] = name
      return acc
    }, {})
  )
  
  const actionTypes = actions.reduce((acc, item) => ({
    ...acc,
    ...addSuffixes(item)
  }), {})

  return Object.freeze(actionTypes)
}