unswallowable thenable

readme.md

an unswallowable thenable

i presently make no claims that this is actually a good idea

WARNING: may not work correctly with async functions

unswallowable.js

'use strict'

module.exports = function unswallowable (promise) {
  return new Unswallowable(promise)
}

class Unswallowable {
  constructor (_promise) {
    this.promise = _promise
    this.hasCatch = false

    this.promise.catch(err => {
      process.nextTick(_ => {
        if (this.hasCatch) return
        throw err
      })
    })
  }

  then (resolve, reject) {
    if (this.hasCatch === false) {
      this.hasCatch = typeof reject === 'function'
    }
    this.promise.then(resolve, reject)
  }

  catch (fn) {
    if (this.hasCatch === false) {
      this.hasCatch = typeof fn === 'function'
    }
    this.promise.catch(fn)
  }

  finally (fn) {
    this.promise.finally(fn)
  }
}