es-node-runner/lib/runner.js

Node runner that transpiles typescript or es modules using blazing fast ⚡ esbuild and restarts the process automatically on change. Suitable for node development server.

import {exec, execSync} from 'child_process';
import {spawn} from 'cross-spawn';
import DEBUG from 'debug';
import {logger} from './utils/index.js';
const debug = DEBUG('es-node-runner:runner');
let child, reRun;
const isWin = process.platform === 'win32';
function run(spawnArgs) {
  debug('spawning new sub process');
  const subProcess = spawn('node', spawnArgs, {
    stdio: [process.stdin, process.stdout, process.stderr],
    env: {
      ...process.env,
    },
  });
  reRun = run.bind(this, spawnArgs);
  if (subProcess.signalCode) {
    debug(`received '${subProcess.signalCode}' signal in sub process`);
    logger.error(
      'The command execution failed because the process exited too early.'
    );
    if (subProcess.signalCode === 'SIGKILL') {
      logger.error(
        'This probably means the system ran out of memory or someone called "kill -9" on the process.\n'
      );
    } else if (subProcess.signalCode === 'SIGTERM') {
      logger.error(
        'Someone might have called `kill` or `killall`, or the system could be shutting down.\n'
      );
    }
    debug('exiting sub process with code 1');
    process.exit(1);
  }
  subProcess.on('spawn', () => {
    debug(
      child?.pid !== subProcess.pid
        ? 'sub process spawned'
        : 'sub process respawned'
    );
    child = subProcess;
  });
  subProcess.on('error', (error) => {
    debug(`error occurred in sub process ${subProcess.pid}`);
    logger.error(`[Error]: ${error.code} - ${error.message}\n`);
    if (error.code === 'ENOENT') {
      debug('exiting sub process with code 1');
      process.exit(1);
    } else {
      throw error;
    }
  });
  subProcess.once('exit', (code) => {
    debug(`sub process ${subProcess.pid} exited with code ${code}`);
    child = null;
    if (code > 0) {
      logger.error(`Sub process exited with code ${code}\n`);
      process.exit(0);
    }
  });
}
function stop() {
  let status = -1;
  if (child && child.pid) {
    debug('terminating child processes');
    if (isWin) {
      debug('executing windows kill cmd');
      try {
        const terminationStatus = execSync(
          `powershell "(Invoke-CimMethod -InputObject (Get-CimInstance Win32_Process | ` +
            `Where-Object { $_.ParentProcessId -eq ${child.pid} }) -MethodName Terminate).ReturnValue"`
        );
        status = terminationStatus.readUInt8(0);
        debug('child processes killed gracefully');
      } catch (error) {
        debug('terminating child processes forcefully');
        try {
          exec(`TASKKILL /PID ${child.pid} /F /T`);
          status = 48;
        } catch (error) {
          logger.error(
            'Could not terminate cleanly. One or more child processes were still running. ' +
              `More info : ${error}\n`
          );
          process.exit(1);
        }
      }
    } else {
      debug('executing non-windows kill cmd');
      try {
        const buffer = execSync(
          `ps --ppid ${child.pid} -o pid | grep -oP '[0-9]+' | xargs -r`
        );
        const pids = buffer.toString().match(/[0-9]+/g);
        if (Array.isArray(pids)) {
          pids.forEach((pid) => exec(`kill -TERM ${pid}`));
        }
        child.kill();
        status = 48;
        debug('child processes killed gracefully');
      } catch (error) {
        logger.error(
          'Could not terminate cleanly. One or more child processes were still running. ' +
            `More info : ${error}\n`
        );
        process.exit(1);
      }
    }
  } else {
    status = 48;
  }
  return status;
}
function restart() {
  debug('restarting process after rebuild');
  if (stop() === 48) {
    reRun();
  } else {
    debug('could not restart process');
    logger.error('Could not restart process\n');
  }
}
export {run, restart};