Before you start implementing new features, please create an issue about it first and discuss your intent.
It might be something that someone else is already implementing or that goes against the concepts of Dropzone, and I really hate rejecting pull requests others spent hours writing on.
The first thing you need to do, is to install the developer dependencies:
$ pnpm installThis will install all the tools you need to compile the source files and to test the library.
Unit tests run against src/ in a real browser with Vitest:
$ pnpm testThe end-to-end tests drive the built files through a real browser, so build first. Playwright starts and stops the test server itself.
$ pnpm build
$ pnpm test:e2e