Why do plain JavaScript templates have @types/ packages?

[codayon]

Why does Vite's react and react-compiler templates include @types/react and @types/react-dom even in the plain JS (non-TypeScript) variant? If someone wanted type support, aren't they supposed to use TypeScript?

[sueun-dev]

@types/react and @types/react-dom are what give you React autocomplete and hover docs inside the plain .jsx files. VS Code (and anything using tsserver) runs the TS language service on JS by default and reads @types straight from node_modules for autocomplete, hover, and JSX attribute completion, no tsconfig or checkJs required.

The template itself shows it's editor-only: template-react ships them as devDeps but no tsconfig/jsconfig, so nothing type-checks your build (template-react-ts is the variant that carries tsconfig). I ran the TS 5.9 language service on the template's App.jsx both ways. With the types, hovering useState gives the full useState(...) signature and a offers the real typed attribute set (className, type, onChange, and so on). Pull @types out and the same query yields a bare import symbol plus a few in-scope identifiers, no real attribute suggestions.

They're type-only devDeps, erased at build time, so safe to remove if you don't want the editor help.

[latent-9]

The @types/react and @types/react-dom packages are there for editor tooling, not for a TypeScript build step. Even in a plain JavaScript project, the TypeScript language server that powers VS Code (and most editors) reads those type definitions to give you IntelliSense, autocomplete, hover info, and inline error checking on React APIs inside your .jsx and .js files. They also let you annotate with JSDoc if you ever want types without switching to TS, and they feed tooling like the ESLint React plugins and the React Compiler, which resolve React's types.

So it is a deliberate editor-DX default, not a mistake. If you genuinely want zero type packages, you can delete both from devDependencies and the app will still build and run fine. You just lose the React autocomplete and type hints in your editor.