Web Dev//HMR

Hot Module Replacement -- when you change a source file, the browser updates only the affected module without a full page reload. App state (forms, scroll position, data) is preserved.

Hot Module Replacement -- when you change a source file, the browser updates only the affected module without a full page reload. App state (forms, scroll position, data) is preserved.

Vite provides HMR for frontend: change a .tsx file, the component updates in the browser instantly

Wrangler has HMR for functions (API/backend): change a handler, Wrangler reloads it. But it does NOT have HMR for frontend -- it serves pre-compiled files from dist/

That's why development uses two terminals: Vite for frontend HMR, Wrangler for the API

Without HMR, every change requires: save > rebuild > manually reload page. With HMR: save --> change appears in the browser