@feflow/cli/src/shared/npm.ts

import spawn from 'cross-spawn';

export function getRegistryUrl(packageManager: string) {
  return new Promise<any>((resolve, reject) => {
    const command = packageManager;
    const args = ['config', 'get', 'registry'];

    const child = spawn(command, args, { windowsHide: true });

    let output = '';

    child.stdout!.on('data', (data) => {
      output += data;
    });

    child.on('close', (code) => {
      if (code !== 0) {
        reject({
          command: `${command} ${args.join(' ')}`
        });
        return;
      }
      output = output.replace(/\n/, '').replace(/\/$/, '');
      resolve(output);
    });
  });
}

export function install(
  packageManager: string,
  root: any,
  cmd: any,
  dependencies: any,
  verbose: boolean,
  isOnline: boolean
) {
  return new Promise((resolve, reject) => {
    const command = packageManager;
    const args = [cmd, '--save', '--save-exact', '--loglevel', 'error'].concat(
      dependencies
    );

    if (verbose) {
      args.push('--verbose');
    }

    const child = spawn(command, args, { stdio: 'inherit', cwd: root, windowsHide: true });
    child.on('close', (code) => {
      if (code !== 0) {
        reject({
          command: `${command} ${args.join(' ')}`
        });
        return;
      }
      resolve();
    });
  });
}