Overriding `/__open-in-editor` route in Vite + SvelteKit

There is a special route in Vite (+ SvelteKit) /__open-in-editor?file=SOURCE-FILE-PATH that opens the source file in an editor (like VS Code.)

Is it possible to override this route? I would like to wrap this route with some extra logic like automatically closing the browser tab that was opened.

I believe this middleware is what handles the route in question.

I tried making an /__open_in_editor route in SvelteKit, but it is never called because Vite's launchEditorMiddleware is run first.

My current work-around is to just make another Kit route /__open. However I would prefer using the same route so that if the /__open_in_editor route is not implemented in SvelteKit, the default Vite middleware is used instead.

A custom vite plugin that handles the __open-in-editor route is processed before the internal middleware:

The configureServer hook is called before internal middlewares are installed, so the custom middlewares will run before internal middlewares by default.

source: vite docs

Commit that added my vite plugin.

Relevant source:

// open-in-editor.ts

    return {
        name: 'open-in-editor',
        configureServer(server) {
            server.middlewares.use('/__open-in-editor', (req, res) => {
                const { file } = url.parse(req.url || '', true).query || {}
                if (!file) {
                    res.statusCode = 500
                    res.end(`launch-editor-middleware: required query param "file" is missing.`)
                } else {
                    res.statusCode = 222
                    launch(path.resolve(srcRoot, file as string), specifiedEditor, onErrorCallback)
                    res.end('<p>You may safely close this window.</p><script>window.close()</script>')
                }
            })
        },
    }

// vite.config.ts
export default defineConfig({
    plugins: [sveltekit(), openInEditorPlugin()],
})