user-conf/index.js

Manage configs in the user home dir

import path from 'path'
import pify from 'pify'
import merge from 'lodash.merge'
import get from 'lodash.get'
import set from 'lodash.set'
import isPlainObject from 'lodash.isplainobject'

// to be promisified
import _fs from 'fs'
import _rimraf from 'rimraf'

const USER_CONF = '__user-conf__'

const fs = pify(_fs)
const rimraf = pify(_rimraf)

class UserConfig {
  constructor (name, base = {}) {
    if (!name || typeof name !== 'string') {
      throw new Error('Expecting name to be non-empty string')
    } else if (!isPlainObject(base)) {
      throw new Error('Expecting base to be plain object')
    }

    this._confFile = path.resolve(
      require('os').homedir(),
      name + '.json'
    )

    if (fs.existsSync(this._confFile)) {
      let conf
      try {
        conf = require(this._confFile)
      } catch (err) {
        throw new Error('Could not load existing config at ' + this._confFile)
      }
      if (!conf[USER_CONF]) {
        throw new Error('File at ' + this._confFile + ' is not user-conf file')
      }
    } else {
      base[USER_CONF] = true
      fs.closeSync(fs.openSync(this._confFile, 'w'))
      const stringy = JSON.stringify(base, null, '\t')
      fs.writeFileSync(this._confFile, stringy)
    }
  }

  /// Private

  _writeJSON (obj) {
    if (!isPlainObject(obj)) {
      throw new Error('Expecting obj to be object')
    }
    obj[USER_CONF] = true
    const stringy = JSON.stringify(obj, null, '\t')
    return fs.writeFile(this._confFile, stringy)
  }

  _writeJSONSync (obj) {
    if (!isPlainObject(obj)) {
      throw new Error('Expecting obj to be object')
    }
    obj[USER_CONF] = true
    const stringy = JSON.stringify(obj, null, '\t')
    fs.writeFileSync(this._confFile, stringy)
  }

  _getJSON () {
    return fs.readFile(this._confFile).then((result) => {
      const json = JSON.parse(String(result))
      delete json[USER_CONF]
      return json
    })
  }

  _getJSONSync () {
    const stringy = String(fs.readFileSync(this._confFile))
    const json = JSON.parse(stringy)
    delete json[USER_CONF]
    return json
  }

  /// Public

  clear () {
    return this._writeJSON({})
  }

  clearSync () {
    this._writeJSONSync({})
  }

  get (key) {
    if (key && typeof key !== 'string') {
      throw new Error('Expecting key to be string')
    }
    return this._getJSON()
      .then((json) => key ? get(json, key) : json)
  }

  getSync (key) {
    if (key && typeof key !== 'string') {
      throw new Error('Expecting key to be string')
    }
    const json = this._getJSONSync()
    return key ? get(json, key) : json
  }

  set (key, val) {
    let json
    if (typeof val === 'undefined') {
      if (!isPlainObject(key)) {
        throw new Error('set expects object if no key given')
      }
      json = key
    } else if (typeof key !== 'string') {
      throw new Error('Expecting key to be string')
    } else {
      json = this._getJSONSync()
      set(json, key, val)
    }
    return this._writeJSON(json)
  }

  setSync (key, val) {
    let json
    if (typeof val === 'undefined') {
      if (!isPlainObject(key)) {
        throw new Error('setSync expects object if no key given')
      }
      json = key
    } else if (typeof key !== 'string') {
      throw new Error('Expecting key to be string')
    } else {
      json = this._getJSONSync()
      set(json, key, val)
    }
    this._writeJSONSync(json)
  }

  update (diff) {
    if (!isPlainObject(diff)) {
      throw new Error('Expecting diff to be object')
    }
    return this.get()
      .then((options) => this.set(merge({}, options, diff)))
      .then(() => this.get())
  }

  updateSync (diff) {
    if (!isPlainObject(diff)) {
      throw new Error('Expecting diff to be object')
    }
    const options = this.getSync()
    const updatedOptions = merge({}, options, diff)
    this.setSync(updatedOptions)
    return this.getSync()
  }

  destroy () {
    return rimraf(this._confFile)
  }
}

module.exports = {
  UserConfig,
  init (...args) {
    return new UserConfig(...args)
  }
}