promdash.src.js

import _ from 'lodash'

export default class Promdash extends Promise {
  then (resolve, reject) {
    const arrayResolution = (...args) => {
      if (resolve) {
        const result = resolve(...args)
        return Array.isArray(result) ? this.constructor.all(result) : result
      }
    }
    return super.then(arrayResolution, reject)
  }
}

Promdash.from = function (promise) {
  if (!promise.then) {
    throw new Error('Promdash.from() requires a `then`able object')
  }
  const P = this || Promdash
  return new P(promise.then.bind(promise))
}

_.functions(_).forEach(f => {
  if (!Promdash.prototype[f]) {
    Promdash.prototype[f] = function (...yargs) {
      return this.then((...xargs) => _[f](...xargs, ...yargs))
    }
  }

  if (!Promdash[f]) {
    Promdash[f] = function (...args) {
      const result = _[f](...args)
      const P = this || Promdash
      return Array.isArray(result) ? P.all(result) : P.resolve(result)
    }
  }
})