spawn-please

Easy and small child_process.spawn.

• Promise-based
• Cross-platform
• Pass stdin as an argument
• Rejects on a non-zero exit code by default

Install

npm install spawn-please

Usage

(
  command: string,
  args?: string[],
  options?: Options,
  spawnOptions?: any,
): Promise<{
  stdout: string
  stderr: string
  code: number | null
}>

import spawn from 'spawn-please'

const { stdout, stderr } = await spawn('printf', ['please?'])

assert.equal(stdout, 'please?')
assert.equal(stderr, '')

Options

• rejectOnError: boolean - Rejects with a SpawnError if the process exits with a non-zero exit code. Default: true.
• stdin: string - Send stdin to the spawned child process.
• stdout: (data: string) => void - Stream stdout by chunk.
• stderr: (data: string) => void - Stream stderr by chunk.

Errors

A process that exits with a non-zero exit code rejects with a SpawnError, which keeps the output that was collected before it failed:

import spawn, { SpawnError } from 'spawn-please'

try {
  await spawn('npm', ['ls', '--json'])
} catch (err) {
  if (err instanceof SpawnError) {
    console.log(err.code) // 1
    console.log(err.stdout) // still usable, even though npm exited non-zero
  }
}

A process that cannot be spawned at all, e.g. the command is not installed, rejects with the underlying ENOENT error. rejectOnError: false does not apply to it, since nothing ran.

License

ISC © Raine Revere