Method findPackageManager

lib/tasks/npm-task.js:142–186

* This method will determine what package manager (npm or yarn) should be * used to install the npm dependencies. * * Setting `this.useYarn` to `true` or `false` will force the use of yarn * or npm respectively. * * If `this.useYarn` is not set we check if `yarn.lock` exists and if

(packageManager = null)

   * @return {Promise}
   */
  async findPackageManager(packageManager = null) {
    if (packageManager === 'yarn') {
      logger.info('yarn requested -> trying yarn');
      return this.checkYarn();
    }

    if (packageManager === 'npm') {
      logger.info('npm requested -> using npm');
      return this.checkNpmVersion();
    }

    if (packageManager === 'pnpm') {
      logger.info('pnpm requested -> using pnpm');
      return this.checkPNPM();
    }

    if (this.hasYarnLock()) {
      logger.info('yarn.lock found -> trying yarn');
      try {
        const yarnResult = await this.checkYarn();
        logger.info('yarn found -> using yarn');
        return yarnResult;
      } catch (_err) {
        logger.info('yarn not found');
      }
    } else {
      logger.info('yarn.lock not found');
    }

    if (await this.hasPNPMLock()) {
      logger.info('pnpm-lock.yaml found -> trying pnpm');
      try {
        let result = await this.checkPNPM();
        logger.info('pnpm found -> using pnpm');
        return result;
      } catch (_err) {
        logger.info('pnpm not found');
      }
    } else {
      logger.info('pnpm-lock.yaml not found');
    }

    logger.info('using npm');
    return this.checkNpmVersion();
  }

  async run(options) {
    this.packageManager = await this.findPackageManager(options.packageManager);