NodeJS pipelining module

chain.js

class Chain {

  constructor() {
    this.chain = []
  }

  use(handler) {
    this.chain.push(handler)
    return this
  }

  handle(context) {

    return new Promise((resolve, reject) => {
      const handlers = this.getChain()[Symbol.iterator]()

      function getHandler(item) {
        return err => {
          if (err)
            return reject(err)
          else if (item.done)
            return resolve(context)
          else
            item.value(context, getHandler(handlers.next()))
        }
      }

      const next = getHandler(handlers.next())
      next()
    })
  }

  getChain() {
    return this.chain.slice()
  }
}

Chain.Chain = Chain
exports = module.exports = Chain