Node.js script to run multiple commands in parallel. Terminates all of them if any of the commands fails. Blog post - https://muffinman.io/blog/node-script-to-run-multiple-commands-in-parallel/

runner.js

import { spawn } from 'child_process';

export class Runner {
  tasks = [];
  exiting = false;
  colors = [
    '\x1b[33m', // yellow
    '\x1b[34m', // blue
    '\x1b[35m', // magenta
    '\x1b[36m', // cyan
  ];

  /**
   * Create a new runner.
   * @param {Object[]} tasks - The x value.
   * @param {string} tasks[].name - The name of the task.
   * @param {string} tasks[].command - The command to run including arguments.
   */
  constructor(tasks) {
    tasks.forEach((task, index) => {
      // Split the command into command and arguments
      const args = task.command.split(' ');
      const command = args.shift();

      // Color the process prefix for output
      const color = this.colors[index % this.colors.length];
      const reset = '\x1b[0m';
      const name = `${color}${task.name}:${reset}`;

      // Spawn the child process
      const childProcess = spawn(command, args);

      // Prefix the output and write to stdout
      childProcess.stdout.on('data', (data) => {
        process.stdout.write(this.addPrefix(data.toString(), name));
      });

      // Prefix the error output and write to stderr
      childProcess.stderr.on('data', (data) => {
        process.stderr.write(this.addPrefix(data.toString(), name));
      });

      // When any process closes, start termination of all processes
      childProcess.on('close', (code, signal) => {
        if (code !== null) {
          console.log(`${name} exited with code ${code}`);
        } else if (signal) {
          console.log(`${name} was killed with signal ${signal}`);
        }

        this.exit();
      });

      // If any process fails to start, terminate all processes
      childProcess.on('error', (error) => {
        console.error(`${name} failed to start: ${error.message}`);

        this.exit();
      });

      // Add task to the list
      this.tasks.push({
        name,
        childProcess,
      });
    });
  }

  // Terminates all processes
  exit() {
    if (!this.exiting) {
      this.exiting = true;

      this.tasks.forEach((task) => {
        if (!task.childProcess.killed) {
          task.childProcess.kill();
        }
      });
    }
  }

  // Add prefix to each line of the text
  // Skips empty lines
  addPrefix(text, prefix) {
    return text
      .split('\n')
      .map((line) => (line ? `${prefix} ${line}` : ''))
      .join('\n');
  }
}

usage.js

import { Runner } from './runner.js';

const tasks = [
  { name: 'sass', command: 'npm run sass' },
  { name: 'build', command: 'npm run build' },
];

new Runner(tasks);