fix: Improve test cleanup and remove non-null assertions

- Add try-finally blocks to ensure NODE_ENV is always restored in tests
- Refactor ensureIndexSet to avoid non-null assertion operator
- Improve test robustness and code safety

All tests passing (244/244)

Co-authored-by: xuyushun441-sys <255036401+xuyushun441-sys@users.noreply.github.com>

Author: Copilot

packages/core/src/api-registry.test.ts

@@ -989,76 +989,82 @@ describe('ApiRegistry', () => {
   describe('Safety Guards', () => {
     it('should allow clear() in non-production environment', () => {
       const originalEnv = process.env.NODE_ENV;
-      process.env.NODE_ENV = 'test';
+      try {
+        process.env.NODE_ENV = 'test';
 
-      registry.registerApi({
-        id: 'test_api',
-        name: 'Test API',
-        type: 'rest',
-        version: 'v1',
-        basePath: '/test',
-        endpoints: [{ id: 'e1', path: '/test', responses: [] }],
-      });
-
-      expect(registry.getStats().totalApis).toBe(1);
-
-      // Should work without force flag in non-production
-      registry.clear();
-      expect(registry.getStats().totalApis).toBe(0);
-
-      process.env.NODE_ENV = originalEnv;
+        registry.registerApi({
+          id: 'test_api',
+          name: 'Test API',
+          type: 'rest',
+          version: 'v1',
+          basePath: '/test',
+          endpoints: [{ id: 'e1', path: '/test', responses: [] }],
+        });
+
+        expect(registry.getStats().totalApis).toBe(1);
+
+        // Should work without force flag in non-production
+        registry.clear();
+        expect(registry.getStats().totalApis).toBe(0);
+      } finally {
+        process.env.NODE_ENV = originalEnv;
+      }
     });
 
     it('should prevent clear() in production without force flag', () => {
       const originalEnv = process.env.NODE_ENV;
-      process.env.NODE_ENV = 'production';
-
-      registry.registerApi({
-        id: 'prod_api',
-        name: 'Production API',
-        type: 'rest',
-        version: 'v1',
-        basePath: '/prod',
-        endpoints: [{ id: 'e1', path: '/prod', responses: [] }],
-      });
-
-      // Should throw error in production without force flag
-      expect(() => registry.clear()).toThrow(
-        'Cannot clear registry in production environment without force flag'
-      );
-
-      // API should still exist
-      expect(registry.getStats().totalApis).toBe(1);
+      try {
+        process.env.NODE_ENV = 'production';
 
-      process.env.NODE_ENV = originalEnv;
+        registry.registerApi({
+          id: 'prod_api',
+          name: 'Production API',
+          type: 'rest',
+          version: 'v1',
+          basePath: '/prod',
+          endpoints: [{ id: 'e1', path: '/prod', responses: [] }],
+        });
+
+        // Should throw error in production without force flag
+        expect(() => registry.clear()).toThrow(
+          'Cannot clear registry in production environment without force flag'
+        );
+
+        // API should still exist
+        expect(registry.getStats().totalApis).toBe(1);
+      } finally {
+        process.env.NODE_ENV = originalEnv;
+      }
     });
 
     it('should allow clear() in production with force flag', () => {
       const originalEnv = process.env.NODE_ENV;
-      process.env.NODE_ENV = 'production';
-
-      registry.registerApi({
-        id: 'prod_api',
-        name: 'Production API',
-        type: 'rest',
-        version: 'v1',
-        basePath: '/prod',
-        endpoints: [{ id: 'e1', path: '/prod', responses: [] }],
-      });
-
-      expect(registry.getStats().totalApis).toBe(1);
-
-      // Should work with force flag
-      registry.clear({ force: true });
-      expect(registry.getStats().totalApis).toBe(0);
-
-      // Verify logger warned about forced clear
-      expect(logger.warn).toHaveBeenCalledWith(
-        'API registry forcefully cleared in production',
-        { force: true }
-      );
+      try {
+        process.env.NODE_ENV = 'production';
 
-      process.env.NODE_ENV = originalEnv;
+        registry.registerApi({
+          id: 'prod_api',
+          name: 'Production API',
+          type: 'rest',
+          version: 'v1',
+          basePath: '/prod',
+          endpoints: [{ id: 'e1', path: '/prod', responses: [] }],
+        });
+
+        expect(registry.getStats().totalApis).toBe(1);
+
+        // Should work with force flag
+        registry.clear({ force: true });
+        expect(registry.getStats().totalApis).toBe(0);
+
+        // Verify logger warned about forced clear
+        expect(logger.warn).toHaveBeenCalledWith(
+          'API registry forcefully cleared in production',
+          { force: true }
+        );
+      } finally {
+        process.env.NODE_ENV = originalEnv;
+      }
     });
 
     it('should clear all indices when clear() is called', () => {

packages/core/src/api-registry.ts

@@ -695,10 +695,12 @@ export class ApiRegistry {
    * @internal
    */
   private ensureIndexSet(map: Map<string, Set<string>>, key: string): Set<string> {
-    if (!map.has(key)) {
-      map.set(key, new Set());
+    let set = map.get(key);
+    if (!set) {
+      set = new Set();
+      map.set(key, set);
     }
-    return map.get(key)!;
+    return set;
   }
 
   /**