POC: Avoid bundling middleware using react-server export conditions and vite plugin

packages/ogimage-gen/empty.js

@@ -0,0 +1,9 @@
+// This file is intentionally left empty, because we do not want to bundle middleware
+
+export default function empty() {
+  console.log(`
+  _______ _     _ _______ _______ _______ _______ _______ _______
+ |______ |_____| |______ |______ |______ |______ |______ |______
+ ______| |     | |______ ______| ______| ______| ______| ______|
+`)
+}

packages/ogimage-gen/package.json

@@ -14,6 +14,7 @@
       "types": "./dist/vite-plugin-ogimage-gen.d.ts"
     },
     "./middleware": {
+      "react-server": "./empty.js",
       "import": "./dist/OgImageMiddleware.js",
       "default": "./cjsWrappers/middleware.js",
       "types": "./dist/OgImageMiddleware.d.ts"
@@ -26,6 +27,7 @@
   },
   "files": [
     "dist",
+    "empty.js",
     "cjsWrappers"
   ],
   "scripts": {

packages/vite/src/lib/getMergedConfig.ts

@@ -172,20 +172,13 @@ function getRollupInput(ssr: boolean): InputOption | undefined {
   }
 
   const ssrEnabled = rwConfig.experimental?.streamingSsr?.enabled
-  const rscEnabled = rwConfig.experimental?.rsc?.enabled
 
   // @NOTE once streaming ssr is out of experimental, this will become the
   // default
   if (ssrEnabled) {
     if (ssr) {
-      if (rscEnabled) {
-        return {
-          Document: rwPaths.web.document,
-        }
-      }
-
       if (!rwPaths.web.entryServer) {
-        throw new Error('entryServer not defined')
+        throw new Error('entryServer not found')
       }
 
       return {

packages/vite/src/middleware/register.ts

@@ -1,8 +1,8 @@
-import fmw from 'find-my-way'
 import type Router from 'find-my-way'
+import fmw from 'find-my-way'
 import type { ViteDevServer } from 'vite'
 
-import { getConfig, getPaths } from '@redwoodjs/project-config'
+import { getPaths } from '@redwoodjs/project-config'
 
 import type { EntryServer } from '../types'
 import { makeFilePath, ssrLoadEntryServer } from '../utils'
@@ -104,25 +104,15 @@ export const createMiddlewareRouter = async (
   vite?: ViteDevServer,
 ): Promise<Router.Instance<any>> => {
   const rwPaths = getPaths()
-  const rwConfig = getConfig()
-  const rscEnabled = rwConfig.experimental?.rsc?.enabled
 
   let entryServerImport: EntryServer
 
   if (vite) {
+    // For Dev Server
     entryServerImport = await ssrLoadEntryServer(vite)
   } else {
     // This imports from dist!
-
-    if (rscEnabled) {
-      entryServerImport = await import(
-        makeFilePath(rwPaths.web.distRscEntryServer)
-      )
-    } else {
-      entryServerImport = await import(
-        makeFilePath(rwPaths.web.distEntryServer)
-      )
-    }
+    entryServerImport = await import(makeFilePath(rwPaths.web.distEntryServer))
   }
 
   const { registerMiddleware } = entryServerImport

packages/vite/src/plugins/vite-plugin-remove-registerMiddlware.ts

@@ -0,0 +1,35 @@
+import * as babel from '@babel/core'
+import type { NodePath } from '@babel/traverse'
+import type * as t from '@babel/types'
+import { createFilter } from 'vite'
+
+import { getPaths } from '@redwoodjs/project-config'
+
+const plugin = () => ({
+  visitor: {
+    VariableDeclarator(path: NodePath<t.VariableDeclarator>) {
+      // @ts-expect-error fggg
+      if (path.node.id.name === 'registerMiddleware') {
+        path.remove()
+      }
+    },
+  },
+})
+
+export default function removeRegisterMiddleware() {
+  const filter = createFilter(getPaths().web.entryServer, 'node_modules/**')
+
+  return {
+    name: 'remove-register-middleware',
+    transform: async (code: string, id: string) => {
+      if (filter(id)) {
+        const result = await babel.transformAsync(code, {
+          plugins: [plugin],
+        })
+        return result?.code
+      }
+
+      return null
+    },
+  }
+}

packages/vite/src/rsc/rscBuildForServer.ts

@@ -4,6 +4,7 @@ import { getPaths } from '@redwoodjs/project-config'
 
 import { getEntries } from '../lib/entries.js'
 import { onWarn } from '../lib/onWarn.js'
+import removeRegisterMiddleware from '../plugins/vite-plugin-remove-registerMiddlware.js'
 import { rscRoutesImports } from '../plugins/vite-plugin-rsc-routes-imports.js'
 import { rscTransformUseClientPlugin } from '../plugins/vite-plugin-rsc-transform-client.js'
 import { rscTransformUseServerPlugin } from '../plugins/vite-plugin-rsc-transform-server.js'
@@ -68,6 +69,7 @@ export async function rscBuildForServer(
       rscTransformUseClientPlugin(clientEntryFiles),
       rscTransformUseServerPlugin(),
       rscRoutesImports(),
+      removeRegisterMiddleware(),
     ],
     build: {
       // TODO (RSC): Remove `minify: false` when we don't need to debug as often