fix(backend): server standalone backend plugins

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

@@ -182,7 +182,11 @@ export function createBackendConfig(
     },
     devtool: isDev ? 'cheap-module-eval-source-map' : 'source-map',
     context: paths.targetPath,
-    entry: ['webpack/hot/poll?100', paths.targetEntry],
+    entry: [
+      'webpack/hot/poll?100',
+      paths.targetEntry,
+      ...(paths.targetRunFile ? [paths.targetRunFile] : []),
+    ],
     resolve: {
       extensions: ['.ts', '.tsx', '.mjs', '.js', '.jsx'],
       mainFields: ['main:src', 'browser', 'module', 'main'],

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

@@ -48,10 +48,15 @@ export function resolveBundlingPaths(options: BundlingPathsOptions) {
     }
   }
 
+  // Backend plugin dev run file
+  const targetRunFile = paths.resolveTarget('src/run.ts');
+  const runFileExists = fs.pathExistsSync(targetRunFile);
+
   return {
     targetHtml,
     targetPublic,
     targetPath: paths.resolveTarget('.'),
+    targetRunFile: runFileExists ? targetRunFile : undefined,
     targetDist: paths.resolveTarget('dist'),
     targetAssets: paths.resolveTarget('assets'),
     targetSrc: paths.resolveTarget('src'),