Add missing getMetrics call in AxBalancer and test mock (#83)

Author: joshvfleming

src/ax/ai/balance.test.ts

@@ -5,6 +5,7 @@ import type {
   AxAIPromptConfig,
   AxAIService,
   AxAIServiceActionOptions,
+  AxAIServiceMetrics,
   AxChatRequest,
   AxChatResponse,
   AxEmbedResponse
@@ -32,6 +33,7 @@ class MockService implements AxAIService {
   getModelConfig = () => ({});
   getFeatures = () => ({ functions: false, streaming: false });
   getModelMap = () => undefined;
+  getMetrics = () => ({}) as AxAIServiceMetrics;
 
   embed = async () => ({}) as AxEmbedResponse;
   setOptions = () => {};

src/ax/ai/balance.ts

@@ -5,6 +5,7 @@ import type {
   AxAIPromptConfig,
   AxAIService,
   AxAIServiceActionOptions,
+  AxAIServiceMetrics,
   AxAIServiceOptions,
   AxChatRequest,
   AxChatResponse,
@@ -105,6 +106,10 @@ export class AxBalancer implements AxAIService {
     return this.currentService.getFeatures(model);
   }
 
+  getMetrics(): AxAIServiceMetrics {
+    return this.currentService.getMetrics();
+  }
+
   async chat(
     req: Readonly<AxChatRequest>,
     options?: Readonly<AxAIPromptConfig & AxAIServiceActionOptions> | undefined