assert-err
assertion library that throws user-specified error types (accepts error class and message)
@simbo/user-facing-error
A custom Error class for creating user-facing error messages with an optional hint to guide users toward resolving issues.
env-paths
Get paths for storing things like data, config, cache, etc
external-editor
Edit a string with the users preferred text editor using $VISUAL or $ENVIRONMENT
untildify
Convert a tilde path to an absolute path: `~/dev` → `/Users/sindresorhus/dev`