pipeline

my-commands.js

const pipeline = {
  mapping: {},
  respond: (regex, func) => {
    this.mapping = this.mapping || {}
    this.mapping[regex.source] = func
  },
  hear: (regex, func) => {
    this.mapping = this.mapping || {}
    this.mapping[regex.source] = func
  },
  innerRegex: /\s+/g,
  buildAnswer: (prefixes) => {
    const innerRegex = `(${Object.keys(this.mapping).join('|')})(?:[\s;]+|$)`
    const globalRegex = `(${prefixes})\\s+((?:${innerRegex})+)`

    return (robot) => robot.respond(new RegExp(globalRegex), (res) => {
      const readOneCommand = (command) => {
        for (const oneMappingEntry of Object.keys(this.mapping)) {
          if (new RegExp(oneMappingEntry).test(command[1])) {
            return this.mapping[oneMappingEntry]
          }
        }
        return () => {
        }
      }
      const instruction = res.match[3]
      const theRegex = new RegExp(innerRegex, 'g')

      let command = theRegex.exec(instruction)
      let promise = Promise.resolve(res)
      while (command) {
        const thisMatch = command
        const func = readOneCommand(command)
        promise = promise.then(() => new Promise((resolve) => {
          const thisRes = Object.assign(Object.create(res), res);
          thisRes.match = thisMatch
          func(robot, thisRes, resolve)
        }))
        command = theRegex.exec(instruction)
      }

      return promise
    })
  }
}

pipeline.respond(/hello(?: again)?/i, (robot, res, resolve) => {res.respond('hello'); resolve();})
pipeline.respond(/how are you/i, (robot, res, resolve) => {res.respond('fine and you'); resolve();})

module.exports = pipeline.buildAnswer('(my-commands)')

//Example : my-commands hello; how are you; hello again