vite.config.ts

import { defineConfig } from 'vite';

export default defineConfig({
  plugins: [

    {
        name: 'vite-plugin-index-html',

        // A custom middleware to intercept the request to the /home route
        configureServer(server) {
            server.middlewares.use(async (req, res, next) => {
                if (req.url === '/home') {
                    res.statusCode = 200;
                    res.setHeader('Content-Type', 'text/html');

                    const shouldResolveToId = 'home.html'

                    await server.moduleGraph.ensureEntryFromUrl(shouldResolveToId, false, true)

                    const resource = await server.pluginContainer.load(shouldResolveToId)
                    if (!resource) {
                        server.config.logger.error(`Failed to load resource ${shouldResolveToId}`)
                        res.statusCode = 500
                        res.write('Failed to load resource')
                        return res.end()
                    }

                    res.write(resource.code)
                    return res.end()
                }

                next();
            });
        },

        configResolved(config) {
            config.build.rollupOptions.input = {
                home: 'home.html'
            }
        },

        resolveId(id) {
            if (id === 'home.html') {
                return id
            }

            if (id.endsWith('?proxy')) {
                return id
            }

            return null
        },


        async load(id) {
            if (id === 'home.html') {
                const proxyCode = await this.load({
                    id: 'some-code?proxy'
                })

                // BUG: Right here, the proxy code is not loaded in the dev mode.
                // The `code` property is missing.
           
                return {
                    code: `<div>Hello World</div><pre>${proxyCode.code}</pre>`,
                }
            }

            if (id.endsWith('?proxy')) {
                const code = `
                    const result = "Hello world"
                    export default result
                `

                return {
                    code: code
                }
            }

            return null
        }
    }
  ],
});