mutation types with prefix

mutation-types-generator.js

const createMutationTypes = (opts) => {
    opts = opts || {};
    let separator = opts.separator || '_'

    if (typeof opts === 'string') {
        opts = {prefix: opts}
    }

    const defineType = (obj, prefix, n, v) => {
        v = v || [].concat.apply([], [prefix, n])
        .join(separator)
        .toUpperCase()
        Object.defineProperty(obj, n, {
            value: v,
            enumerable: true,
            writable: false,
            configurable: false
        })
        return obj
    }

    const definer = (obj, prefix) => {

        return (...definitions) => {
            definitions.forEach((def) => {
                defineType(obj, prefix, def);
            })

            return obj
        }
    }

    let prefix = opts.prefix || '';
    return definer({}, prefix);
}

export default createMutationTypes

mutation-types.js

import createMutationTypes from './mutation-types-generator'

export default createMutationTypes('auth')(
    'LOGGED_IN',
    'ERRORS',
    'PENDING'
)

/*
  * expected output
  * { LOGGED_IN: 'AUTH_LOGGED_IN', ERRORS: 'AUTH_ERRORS', PENDING: 'AUTH_PENDING' }
  *
*/

mutation.js

import types from './mutation-types.js'


const mutation = {
    [types.LOGGED_IN](state, { credentials }) {
        state.credentials = credentials
    },
    [types.ERRORS](state, { errors}) {
        state.errors = errors
    },
    [types.PENGING](state, { message }) {
        state.message = message 
    }
    
}

export default mutation