The best way to run npm install for nested folders?

Question

What is the most correct way to install npm packages in nested sub folders?

my-app
  /my-sub-module
  package.json
package.json

<

Answer 1

Inspired by the scripts provided here, I built a configurable example which:

• can be setup to use yarn or npm
• can be setup to determine the command to use based on lock files so that if you set it to use yarn but a directory only has a package-lock.json it will use npm for that directory (defaults to true).
• configure logging
• runs installations in parallel using cp.spawn
• can do dry runs to let you see what it would do first
• can be run as a function or auto run using env vars
  • when run as a function, optionally provide array of directories to check
• returns a promise that resolves when completed
• allows setting max depth to look if needed
• knows to stop recursing if it finds a folder with yarn workspaces (configurable)
• allows skipping directories using a comma separated env var or by passing the config an array of strings to match against or a function which receives the file name, file path, and the fs.Dirent obj and expects a boolean result.

const path = require('path');
const { promises: fs } = require('fs');
const cp = require('child_process');

// if you want to have it automatically run based upon
// process.cwd()
const AUTO_RUN = Boolean(process.env.RI_AUTO_RUN);

/**
 * Creates a config object from environment variables which can then be
 * overriden if executing via its exported function (config as second arg)
 */
const getConfig = (config = {}) => ({
  // we want to use yarn by default but RI_USE_YARN=false will
  // use npm instead
  useYarn: process.env.RI_USE_YARN !== 'false',
  // should we handle yarn workspaces?  if this is true (default)
  // then we will stop recursing if a package.json has the "workspaces"
  // property and we will allow `yarn` to do its thing.
  yarnWorkspaces: process.env.RI_YARN_WORKSPACES !== 'false',
  // if truthy, will run extra checks to see if there is a package-lock.json
  // or yarn.lock file in a given directory and use that installer if so.
  detectLockFiles: process.env.RI_DETECT_LOCK_FILES !== 'false',
  // what kind of logging should be done on the spawned processes?
  // if this exists and it is not errors it will log everything
  // otherwise it will only log stderr and spawn errors
  log: process.env.RI_LOG || 'errors',
  // max depth to recurse?
  maxDepth: process.env.RI_MAX_DEPTH || Infinity,
  // do not install at the root directory?
  ignoreRoot: Boolean(process.env.RI_IGNORE_ROOT),
  // an array (or comma separated string for env var) of directories
  // to skip while recursing. if array, can pass functions which
  // return a boolean after receiving the dir path and fs.Dirent args
  // @see https://nodejs.org/api/fs.html#fs_class_fs_dirent
  skipDirectories: process.env.RI_SKIP_DIRS
    ? process.env.RI_SKIP_DIRS.split(',').map(str => str.trim())
    : undefined,
  // just run through and log the actions that would be taken?
  dry: Boolean(process.env.RI_DRY_RUN),
  ...config
});

function handleSpawnedProcess(dir, log, proc) {
  return new Promise((resolve, reject) => {
    proc.on('error', error => {
      console.log(`
----------------
  [RI] | [ERROR] | Failed to Spawn Process
  - Path:   ${dir}
  - Reason: ${error.message}
----------------
  `);
      reject(error);
    });

    if (log) {
      proc.stderr.on('data', data => {
        console.error(`[RI] | [${dir}] | ${data}`);
      });
    }

    if (log && log !== 'errors') {
      proc.stdout.on('data', data => {
        console.log(`[RI] | [${dir}] | ${data}`);
      });
    }

    proc.on('close', code => {
      if (log && log !== 'errors') {
        console.log(`
----------------
  [RI] | [COMPLETE] | Spawned Process Closed
  - Path: ${dir}
  - Code: ${code}
----------------
        `);
      }
      if (code === 0) {
        resolve();
      } else {
        reject(
          new Error(
            `[RI] | [ERROR] | [${dir}] | failed to install with exit code ${code}`
          )
        );
      }
    });
  });
}

async function recurseDirectory(rootDir, config) {
  const {
    useYarn,
    yarnWorkspaces,
    detectLockFiles,
    log,
    maxDepth,
    ignoreRoot,
    skipDirectories,
    dry
  } = config;

  const installPromises = [];

  function install(cmd, folder, relativeDir) {
    const proc = cp.spawn(cmd, ['install'], {
      cwd: folder,
      env: process.env
    });
    installPromises.push(handleSpawnedProcess(relativeDir, log, proc));
  }

  function shouldSkipFile(filePath, file) {
    if (!file.isDirectory() || file.name === 'node_modules') {
      return true;
    }
    if (!skipDirectories) {
      return false;
    }
    return skipDirectories.some(check =>
      typeof check === 'function' ? check(filePath, file) : check === file.name
    );
  }

  async function getInstallCommand(folder) {
    let cmd = useYarn ? 'yarn' : 'npm';
    if (detectLockFiles) {
      const [hasYarnLock, hasPackageLock] = await Promise.all([
        fs
          .readFile(path.join(folder, 'yarn.lock'))
          .then(() => true)
          .catch(() => false),
        fs
          .readFile(path.join(folder, 'package-lock.json'))
          .then(() => true)
          .catch(() => false)
      ]);
      if (cmd === 'yarn' && !hasYarnLock && hasPackageLock) {
        cmd = 'npm';
      } else if (cmd === 'npm' && !hasPackageLock && hasYarnLock) {
        cmd = 'yarn';
      }
    }
    return cmd;
  }

  async function installRecursively(folder, depth = 0) {
    if (dry || (log && log !== 'errors')) {
      console.log('[RI] | Check Directory --> ', folder);
    }

    let pkg;

    if (folder !== rootDir || !ignoreRoot) {
      try {
        // Check if package.json exists, if it doesnt this will error and move on
        pkg = JSON.parse(await fs.readFile(path.join(folder, 'package.json')));
        // get the command that we should use.  if lock checking is enabled it will
        // also determine what installer to use based on the available lock files
        const cmd = await getInstallCommand(folder);
        const relativeDir = `${path.basename(rootDir)} -> ./${path.relative(
          rootDir,
          folder
        )}`;
        if (dry || (log && log !== 'errors')) {
          console.log(
            `[RI] | Performing (${cmd} install) at path "${relativeDir}"`
          );
        }
        if (!dry) {
          install(cmd, folder, relativeDir);
        }
      } catch {
        // do nothing when error caught as it simply indicates package.json likely doesnt
        // exist.
      }
    }

    if (
      depth >= maxDepth ||
      (pkg && useYarn && yarnWorkspaces && pkg.workspaces)
    ) {
      // if we have reached maxDepth or if our package.json in the current directory
      // contains yarn workspaces then we use yarn for installing then this is the last
      // directory we will attempt to install.
      return;
    }

    const files = await fs.readdir(folder, { withFileTypes: true });

    return Promise.all(
      files.map(file => {
        const filePath = path.join(folder, file.name);
        return shouldSkipFile(filePath, file)
          ? undefined
          : installRecursively(filePath, depth + 1);
      })
    );
  }

  await installRecursively(rootDir);
  await Promise.all(installPromises);
}

async function startRecursiveInstall(directories, _config) {
  const config = getConfig(_config);
  const promise = Array.isArray(directories)
    ? Promise.all(directories.map(rootDir => recurseDirectory(rootDir, config)))
    : recurseDirectory(directories, config);
  await promise;
}

if (AUTO_RUN) {
  startRecursiveInstall(process.cwd());
}

module.exports = startRecursiveInstall;

---

And with it being used:

const installRecursively = require('./recursive-install');

installRecursively(process.cwd(), { dry: true })