feat: add role-specific statistics to telemetry and UI (cont. #15234) (#18824)

Co-authored-by: Yuna Seol <yunaseol@google.com>

packages/core/src/code_assist/server.test.ts

@@ -9,6 +9,7 @@ import { CodeAssistServer } from './server.js';
 import { OAuth2Client } from 'google-auth-library';
 import { UserTierId, ActionStatus } from './types.js';
 import { FinishReason } from '@google/genai';
+import { LlmRole } from '../telemetry/types.js';
 
 vi.mock('google-auth-library');
 
@@ -69,6 +70,7 @@ describe('CodeAssistServer', () => {
         contents: [{ role: 'user', parts: [{ text: 'request' }] }],
       },
       'user-prompt-id',
+      LlmRole.MAIN,
     );
 
     expect(mockRequest).toHaveBeenCalledWith({
@@ -126,6 +128,7 @@ describe('CodeAssistServer', () => {
         contents: [{ role: 'user', parts: [{ text: 'request' }] }],
       },
       'user-prompt-id',
+      LlmRole.MAIN,
     );
 
     expect(recordConversationOfferedSpy).toHaveBeenCalledWith(
@@ -170,6 +173,7 @@ describe('CodeAssistServer', () => {
         contents: [{ role: 'user', parts: [{ text: 'request' }] }],
       },
       'user-prompt-id',
+      LlmRole.MAIN,
     );
 
     expect(server.recordCodeAssistMetrics).toHaveBeenCalledWith(
@@ -208,6 +212,7 @@ describe('CodeAssistServer', () => {
         contents: [{ role: 'user', parts: [{ text: 'request' }] }],
       },
       'user-prompt-id',
+      LlmRole.MAIN,
     );
 
     const mockResponseData = {
@@ -369,6 +374,7 @@ describe('CodeAssistServer', () => {
         contents: [{ role: 'user', parts: [{ text: 'request' }] }],
       },
       'user-prompt-id',
+      LlmRole.MAIN,
     );
 
     // Push SSE data to the stream

packages/core/src/code_assist/server.ts

@@ -53,6 +53,7 @@ import {
   recordConversationOffered,
 } from './telemetry.js';
 import { getClientMetadata } from './experiments/client_metadata.js';
+import type { LlmRole } from '../telemetry/types.js';
 /** HTTP options to be used in each of the requests. */
 export interface HttpOptions {
   /** Additional HTTP headers to be sent with the request. */
@@ -75,6 +76,8 @@ export class CodeAssistServer implements ContentGenerator {
   async generateContentStream(
     req: GenerateContentParameters,
     userPromptId: string,
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
+    role: LlmRole,
   ): Promise<AsyncGenerator<GenerateContentResponse>> {
     const responses =
       await this.requestStreamingPost<CaGenerateContentResponse>(
@@ -125,6 +128,8 @@ export class CodeAssistServer implements ContentGenerator {
   async generateContent(
     req: GenerateContentParameters,
     userPromptId: string,
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
+    role: LlmRole,
   ): Promise<GenerateContentResponse> {
     const start = Date.now();
     const response = await this.requestPost<CaGenerateContentResponse>(