refactor(backend-dynamic-feature-service): allow passing an async module loader in the DynamicPluginsFeatureLoaderOptions.

Signed-off-by: David Festal <dfestal@redhat.com>

.changeset/lemon-badgers-share.md

@@ -0,0 +1,5 @@
+---
+'@backstage/backend-dynamic-feature-service': patch
+---
+
+Allow passing an async module loader in the `DynamicPluginsFeatureLoaderOptions`.

packages/backend-dynamic-feature-service/src/loader/CommonJSModuleLoader.ts

@@ -18,7 +18,11 @@ import { LoggerService } from '@backstage/backend-plugin-api';
 import path from 'path';
 
 export class CommonJSModuleLoader implements ModuleLoader {
-  constructor(public readonly logger: LoggerService) {}
+  private module: any;
+
+  constructor(public readonly logger: LoggerService) {
+    this.module = require('node:module');
+  }
 
   async bootstrap(
     backstageRoot: string,
@@ -28,9 +32,8 @@ export class CommonJSModuleLoader implements ModuleLoader {
     const dynamicNodeModulesPaths = [
       ...dynamicPluginsPaths.map(p => path.resolve(p, 'node_modules')),
     ];
-    const Module = require('module');
-    const oldNodeModulePaths = Module._nodeModulePaths;
-    Module._nodeModulePaths = (from: string): string[] => {
+    const oldNodeModulePaths = this.module._nodeModulePaths;
+    this.module._nodeModulePaths = (from: string): string[] => {
       const result: string[] = oldNodeModulePaths(from);
       if (!dynamicPluginsPaths.some(p => from.startsWith(p))) {
         return result;
@@ -49,6 +52,6 @@ export class CommonJSModuleLoader implements ModuleLoader {
   }
 
   async load(packagePath: string): Promise<any> {
-    return await require(/* webpackIgnore: true */ packagePath);
+    return await this.module.prototype.require(packagePath);
   }
 }

packages/backend-dynamic-feature-service/src/manager/plugin-manager.ts

@@ -88,7 +88,7 @@ export class DynamicPluginManager implements DynamicPluginProvider {
       ),
     );
 
-    moduleLoader.bootstrap(backstageRoot, dynamicPluginsPaths);
+    await moduleLoader.bootstrap(backstageRoot, dynamicPluginsPaths);
 
     scanner.subscribeToRootDirectoryChange(async () => {
       manager._availablePackages = (await scanner.scanRoot()).packages;
@@ -262,7 +262,7 @@ export const dynamicPluginsServiceRef = createServiceRef<DynamicPluginProvider>(
  * @public
  */
 export interface DynamicPluginsFactoryOptions {
-  moduleLoader?(logger: LoggerService): ModuleLoader;
+  moduleLoader?(logger: LoggerService): ModuleLoader | Promise<ModuleLoader>;
 }
 
 /**
@@ -283,7 +283,7 @@ export const dynamicPluginsServiceFactoryWithOptions = (
         config,
         logger,
         preferAlpha: true,
-        moduleLoader: options?.moduleLoader?.(logger),
+        moduleLoader: await options?.moduleLoader?.(logger),
       });
     },
   });