next.js/packages/create-next-app/helpers/install.ts

/* eslint-disable import/no-extraneous-dependencies */
import { yellow } from 'picocolors'
import spawn from 'cross-spawn'
import type { PackageManager } from './get-pkg-manager'

/**
 * Spawn a package manager installation based on user preference.
 *
 * @returns A Promise that resolves once the installation is finished.
 */
export async function install(
  /** Indicate which package manager to use. */
  packageManager: PackageManager,
  /** Indicate whether there is an active Internet connection.*/
  isOnline: boolean
): Promise<void> {
  const args: string[] = ['install']
  if (!isOnline) {
    console.log(
      yellow('You appear to be offline.\nFalling back to the local cache.')
    )
    args.push('--offline')
  }
  /**
   * Return a Promise that resolves once the installation is finished.
   */
  return new Promise((resolve, reject) => {
    /**
     * Spawn the installation process.
     */
    const child = spawn(packageManager, args, {
      stdio: 'inherit',
      env: {
        ...process.env,
        ADBLOCK: '1',
        // we set NODE_ENV to development as pnpm skips dev
        // dependencies when production
        NODE_ENV: 'development',
        DISABLE_OPENCOLLECTIVE: '1',
      },
    })
    child.on('close', (code) => {
      if (code !== 0) {
        reject({ command: `${packageManager} ${args.join(' ')}` })
        return
      }
      resolve()
    })
  })
}