harness/process.ts

import { spawn } from 'node:child_process'

export type CommandResult = {
  code: number | null
  signal: NodeJS.Signals | null
  stdout: string
  stderr: string
  durationMs: number
  timedOut: boolean
}

export function runCommand(
  command: string,
  args: string[],
  options: {
    cwd: string
    env?: Record<string, string | undefined>
    timeoutMs: number
    stdinText?: string
  },
): Promise<CommandResult> {
  return new Promise(resolve => {
    const startedAt = performance.now()
    const child = spawn(command, args, {
      cwd: options.cwd,
      env: {
        ...process.env,
        ...options.env,
      },
      stdio: 'pipe',
      windowsHide: true,
    })
    let stdout = ''
    let stderr = ''
    let timedOut = false

    child.stdout.on('data', chunk => {
      stdout += String(chunk)
    })
    child.stderr.on('data', chunk => {
      stderr += String(chunk)
    })

    if (options.stdinText !== undefined) {
      child.stdin.write(options.stdinText)
    }
    child.stdin.end()

    const timer = setTimeout(() => {
      timedOut = true
      child.kill()
    }, options.timeoutMs)

    child.on('close', (code, signal) => {
      clearTimeout(timer)
      resolve({
        code,
        signal,
        stdout,
        stderr,
        durationMs: performance.now() - startedAt,
        timedOut,
      })
    })
  })
}