gensync

Allows users to use generators in order to write common functions that can be both sync or async.

synckit

Perform async work synchronously in Node.js using `worker_threads` with first-class TypeScript support.

workbox-background-sync

Queues failed requests and uses the Background Sync API to replay them when the network is available

find-pkg

Find the first directory with a package.json, recursing up, starting with the given directory. Similar to look-up but does not support globs and only searches for package.json. Async and sync.