fix: clear nodeRuntimeImportCache between tests to prevent interference

Export the cache and clear it in beforeEach to ensure test isolation.
The caching mechanism was causing tests to reuse cached promises from
previous tests instead of running the intended mocked behavior.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: ScriptedAlchemy

packages/node/src/__tests__/runtimePlugin.test.ts

@@ -11,6 +11,7 @@ import runtimePlugin, {
   setupScriptLoader,
   setupChunkHandler,
   setupWebpackRequirePatching,
+  nodeRuntimeImportCache,
 } from '../runtimePlugin';
 import type {
   ModuleFederationRuntimePlugin,
@@ -139,6 +140,8 @@ describe('runtimePlugin', () => {
     beforeEach(() => {
       originalFunction = global.Function;
       console.error = jest.fn();
+      // Clear the import cache to ensure fresh tests
+      nodeRuntimeImportCache.clear();
     });
 
     afterEach(() => {

packages/node/src/runtimePlugin.ts

@@ -41,6 +41,9 @@ declare const __non_webpack_require__: (id: string) => any;
 
 const nodeRuntimeImportCache = new Map<string, Promise<any>>();
 
+// Export cache for testing
+export { nodeRuntimeImportCache };
+
 export function importNodeModule<T>(name: string): Promise<T> {
   if (!name) {
     throw new Error('import specifier is required');