`Promise` wrapper around `require('child_process').spawn` that runs a process to completion with a given `stdin` and collects `stdout`, `stderr`, and the exit code.

runExternalProcessAsync.js

const spawn = require('child_process').spawn;

async function runExternalProcessAsync({ procExecutable, procArgs, procStdinString }) {
  const proc = await new Promise((resolve) => {
    resolve(spawn(procExecutable, procArgs));
  });
  try {
    return await new Promise((resolve, reject) => {
      const procStdoutParts = [];
      const procStderrParts = [];
      proc.stdout.on('data', (data) => {
        procStdoutParts.push(String(data));
      });
      proc.stdout.on('error', (error) => {
        reject(error);
      });
      proc.stderr.on('data', (data) => {
        procStderrParts.push(String(data));
      });
      proc.stderr.on('error', (error) => {
        reject(error);
      });
      proc.on('error', (error) => {
        reject(error);
      });
      proc.on('exit', (procExitCode) => {
        const procStdout = procStdoutParts.join('');
        const procStderr = procStderrParts.join('');
        resolve({
          procStdout: procStdout,
          procStderr: procStderr,
          procExitCode: procExitCode,
        });
      });
      proc.stdin.write(procStdinString || '');
      proc.stdin.end();
    });
  } catch (procError) {
    throw procError;
  } finally {
    proc.kill();
  }
}

module.export = {
  runExternalProcessAsync,
};

runExternalProcessAsync.js_README.md

Overview

Promise wrapper around require('child_process').spawn that runs a process to completion with a given stdin and collects stdout, stderr, and the exit code.

Usage

  // Fix errors in a zip archive.
  const { procExitCode, procStdout, procStderr } = await runExternalProcessAsync({
    procExecutable: 'zip',
    procArgs: ['-FF', zipTempPath, '--out', zipFixedTempPath],
    procStdinString: 'y',
  });