Untry

Better error handling in JavaScript

This library provides a simple way to handle errors in JavaScript, inspired by the error handling philosophy in Go.

Installation

npm

npm install untry

yarn

yarn add untry

Usage

untry executes a function and return an array with the resulting value in the first place, and the thrown error in the second one.

import untry from 'untry'

let [value, error] = untry(() => someFunc())

// async
let [value, error] = await untry(() => someFunc())

Defer

Defer executes the passed functions if any error is thrown inside the untry execution.

let [value, error] = untry((defer) => {
  defer(error => {
    // execute if any error
  })

  // function code
  return someFunc()
})

Example:

import fs from 'node:fs/promises'

let [value, error] = untry((defer) => {
  let filehandle

  // close file handler if something unexpected happens
  defer(error => {
    console.log(error)
    if (filehandle) filehandle.close()
  })

  filehandle = await fs.open('/Users/joe/test.txt', 'r')
  return filehandle.readFile({ encoding: 'utf8' })
})

Utilities

error(err: Error, name: string): CustomError

Returns a serializable custom Error

const err = untry.error(new Error('Bad token!'), 'TOKEN_ERROR')

console.log(JSON.stringify(err))

/*
Console output

{
  '@untry/error': true,
  'name': 'TOKEN_ERROR',
  'message': 'Bad token!'
}
*/

Contributing

Contributions are welcome! Please submit a pull request or issue on GitHub.

License

MIT (c) 2019-present Yosbel Marin