refactor(api): allow router handler injection in tests

ts/api/router.ts

@@ -22,6 +22,14 @@ interface IParsedRequestBody {
   body?: unknown;
 }
 
+interface IApiRouterOptions {
+  chatHandler?: ChatHandler;
+  modelsHandler?: ModelsHandler;
+  embeddingsHandler?: EmbeddingsHandler;
+  authMiddleware?: AuthMiddleware;
+  sanityMiddleware?: SanityMiddleware;
+}
+
 /**
  * API Router - routes requests to handlers
  */
@@ -42,6 +50,7 @@ export class ApiRouter {
     modelLoader: ModelLoader,
     clusterCoordinator: ClusterCoordinator,
     apiKeys: string[],
+    options: IApiRouterOptions = {},
   ) {
     this.containerManager = containerManager;
     this.modelRegistry = modelRegistry;
@@ -49,22 +58,23 @@ export class ApiRouter {
     this.clusterCoordinator = clusterCoordinator;
 
     // Initialize handlers
-    this.chatHandler = new ChatHandler(
+    this.chatHandler = options.chatHandler || new ChatHandler(
       containerManager,
       modelRegistry,
       modelLoader,
       clusterCoordinator,
     );
-    this.modelsHandler = new ModelsHandler(containerManager, modelRegistry, clusterCoordinator);
-    this.embeddingsHandler = new EmbeddingsHandler(
+    this.modelsHandler =
+      options.modelsHandler || new ModelsHandler(containerManager, modelRegistry, clusterCoordinator);
+    this.embeddingsHandler = options.embeddingsHandler || new EmbeddingsHandler(
       containerManager,
       modelRegistry,
       clusterCoordinator,
     );
 
     // Initialize middleware
-    this.authMiddleware = new AuthMiddleware(apiKeys);
-    this.sanityMiddleware = new SanityMiddleware(modelRegistry);
+    this.authMiddleware = options.authMiddleware || new AuthMiddleware(apiKeys);
+    this.sanityMiddleware = options.sanityMiddleware || new SanityMiddleware(modelRegistry);
   }
 
   /**