Check if a string is a valid filename
When copying or moving files, it's common for operating systems to automatically add an increment or 'copy' to duplicate file names. This does that for Node.js applications, with automatic platform detection and support for Linux, MacOs, and Windows conventions.
Create and parse HTTP Content-Disposition header
Generate a unique filename for use in temporary directories or caches.
Get an unused filename by appending a number if it exists: `file.txt` → `file (1).txt`