fix: add react and react-dom to resolve.dedupe at config

[lazarv]

Adds "react" and "react-dom" to resolve.dedupe in the config hook. @vitejs/plugin-react does the same at https://github.com/vitejs/vite-plugin-react/blob/main/packages/plugin-react/src/index.ts#L289-L291.

For some context, the missing dedupe of these React packages caused issues in my own React meta-framework (@lazarv/react-server) when adding support for @vitejs/plugin-react-swc. Using Vite Environment API it was not able to resolve "react/jsx-dev-runtime". I usually work on the framework in a pnpm workspace and the framework also provides it's own strict experimental React version.

[ArnaudBarre]

My plan is to do the opposite and remove the dedupe option from the Babel plugin: vitejs/vite-plugin-react#280 (comment)

For me users should always have exactly one version of React installed. Why is this not the case for you?
How can you be sure that the dedupe option will keep the one you want?

[lazarv]

My issue is that Vite uses dedupe to select the root at https://github.com/vitejs/vite/blob/14e14726d11ac55c37cc2d15aaf935be18ef925b/packages/vite/src/node/plugins/resolve.ts#L726-L737

if (dedupe?.includes(pkgId)) {
  basedir = root
} else if (
  importer &&
  path.isAbsolute(importer) &&
  // css processing appends `*` for importer
  (importer[importer.length - 1] === '*' || fs.existsSync(cleanUrl(importer)))
) {
  basedir = path.dirname(importer)
} else {
  basedir = root
}

With a root at /Users/lazarv/Projects/react-server/packages/react-server and having an importer at /Users/lazarv/Projects/react-server/examples/todo/src/index.tsx, when it's trying to resolve react/jsx-dev-runtime and if I don't have react in dedupe then the basedir will be incorrect as it's using the importer's directory, while I only have a resolvable React in the root.

I had a lot of resolution issues because React is not installed in the consumer project, so I do a lot of resolution workarounds to achieve what's necessary for the framework to work like a CLI tool too on any given React component file.

Sorry @ArnaudBarre I missed the existing PR at @vitejs/plugin-react removing resolve.dedupe. My current workaround is to add both react and react-dom to the Vite config in my framework. As everything worked as expected with the Babel version of the plugin, I suspected that resolve.dedupe is just missing here.