cli-helpers

cli-helpers

Helper library for building cli applications

Features

• Multi-Line I/O interface
  • async io.question(text) for ease of use
  • buffered input prevents data lost when pasting multi-line input
  • customizable I/O stream using process.stdin and process.stdout as default
  • flushable buffer to get pending input lines
• Typescript support

Installation

npm install cli-helpers

You can also install cli-helpers with pnpm, yarn, or slnpm

Usage Example

import { createIO } from 'cli-helpers'

async function main() {
  let io = createIO()
  for (;;) {
    let line = await io.question('> ')
    console.log('line:', line)
    if (line == 'exit') {
      break
    }
  }
  io.close()
}

main().catch(e => console.error(e))

Typescript Signature

io helper functions:

import { ReadLineOptions } from 'readline'

/**
 * @description async io interface based on `readline.createInterface()`.
 * With internal buffer to avoid data lose when pasting multi-lines input.
 */
export function createIO(options?: {
  input?: ReadLineOptions['input']
  output?: ReadLineOptions['output']
}): {
  question: (question: string) => Promise<string>
  close: () => void
  flush: () => string[]
}

file helper functions:

/**
 * @description look for the file from the current or parent directory recursively
 * @example
 * ```
 * let file = resolveFile('package.json')
 * let pkg = readJSONFile(file)
 * ```
 */
export function resolveFile(filename: string): string

/**
 * @description read file as json data
 * @throws JSONFileError
 */
export function readJSONFile(file: string): any

/**
 * @description write json data to file
 * @throws JSONFileError
 */
export function writeJSONFile(file: string, data: any): void

export class JSONFileError extends Error {
  file: string
}

License

This project is licensed with BSD-2-Clause

This is free, libre, and open-source software. It comes down to four essential freedoms [ref]:

• The freedom to run the program as you wish, for any purpose
• The freedom to study how the program works, and change it so it does your computing as you wish
• The freedom to redistribute copies so you can help others
• The freedom to distribute copies of your modified versions to others