cli: revert rspack additions to backend bundling

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

packages/cli/src/lib/bundler/backend.ts

@@ -20,24 +20,17 @@ import { resolveBundlingPaths } from './paths';
 import { BackendServeOptions } from './types';
 
 export async function serveBackend(options: BackendServeOptions) {
-  const useRspack = !!process.env.EXPERIMENTAL_RSPACK;
-
   const paths = resolveBundlingPaths(options);
   const config = await createBackendConfig(paths, {
     ...options,
     isDev: true,
-    useRspack,
   });
 
   // Webpack only replaces occurrences of this in code it touches, which does
   // not include dependencies in node_modules. So we set it here at runtime as well.
   (process.env as { NODE_ENV: string }).NODE_ENV = 'development';
 
-  const bundler: typeof webpack = useRspack
-    ? require('@rspack/core').rspack
-    : webpack;
-
-  const compiler = bundler(config, (err: Error | null) => {
+  const compiler = webpack(config, (err: Error | null) => {
     if (err) {
       console.error(err);
     } else console.log('Build succeeded');

packages/cli/src/lib/bundler/config.ts

@@ -447,7 +447,7 @@ export async function createBackendConfig(
   paths: BundlingPaths,
   options: BackendBundlingOptions,
 ): Promise<webpack.Configuration> {
-  const { checksEnabled, isDev, useRspack } = options;
+  const { checksEnabled, isDev } = options;
 
   // Find all local monorepo packages and their node_modules, and mark them as external.
   const { packages } = await getPackages(cliPaths.targetDir);
@@ -518,16 +518,13 @@ export async function createBackendConfig(
       extensions: ['.ts', '.mjs', '.js', '.json'],
       mainFields: ['main'],
       modules: [paths.rootNodeModules, ...moduleDirs],
-      // FIXME: see also https://github.com/web-infra-dev/rspack/issues/3408
-      ...(!useRspack && {
-        plugins: [
-          new LinkedPackageResolvePlugin(paths.rootNodeModules, externalPkgs),
-          new ModuleScopePlugin(
-            [paths.targetSrc, paths.targetDev],
-            [paths.targetPackageJson],
-          ),
-        ],
-      }),
+      plugins: [
+        new LinkedPackageResolvePlugin(paths.rootNodeModules, externalPkgs),
+        new ModuleScopePlugin(
+          [paths.targetSrc, paths.targetDev],
+          [paths.targetPackageJson],
+        ),
+      ],
     },
     module: {
       rules: loaders,
@@ -554,9 +551,7 @@ export async function createBackendConfig(
         nodeArgs: runScriptNodeArgs.length > 0 ? runScriptNodeArgs : undefined,
         args: process.argv.slice(3), // drop `node backstage-cli backend:dev`
       }),
-      new (useRspack
-        ? require('@rspack/core').rspack.HotModuleReplacementPlugin
-        : webpack.HotModuleReplacementPlugin)(),
+      new webpack.HotModuleReplacementPlugin(),
       ...(checksEnabled
         ? [
             new ForkTsCheckerWebpackPlugin({