chore(server): forbidden vi.mock and vi.hoist

apps/server/src/routes/openai/v1/index.ts

@@ -8,6 +8,7 @@ import type { BillingService } from '../../../services/domain/billing/billing-se
 import type { FluxMeter } from '../../../services/domain/billing/flux-meter'
 import type { FluxService } from '../../../services/domain/flux'
 import type { LlmRouteContext, LlmRouterService } from '../../../services/domain/llm-router'
+import type { ChatGenerationTrace, TtsGenerationTrace } from '../../../services/domain/llm-tracing'
 import type { RequestLogService } from '../../../services/domain/request-log'
 import type { HonoEnv } from '../../../types/hono'
 
@@ -36,6 +37,11 @@ import {
 
 const tracer = trace.getTracer('v1-completions')
 
+interface LlmTracingDeps {
+  startChatGeneration: (input: Parameters<typeof startChatGeneration>[0]) => ChatGenerationTrace
+  startTtsGeneration: (input: Parameters<typeof startTtsGeneration>[0]) => TtsGenerationTrace
+}
+
 const SAFE_RESPONSE_HEADERS = new Set([
   'content-type',
   'content-length',
@@ -94,6 +100,7 @@ export function createV1Routes(
   revenue?: RevenueMetrics | null,
   rateLimitMetrics?: RateLimitMetrics | null,
   posthog?: PostHog | null,
+  llmTracing: LlmTracingDeps = { startChatGeneration, startTtsGeneration },
 ) {
   const logger = useLogger('v1-completions').useGlobalConfig()
   // TODO: Extract this compat route into smaller facades/modules.
@@ -199,7 +206,7 @@ export function createV1Routes(
     catch (err) {
       span.setStatus({ code: SpanStatusCode.ERROR, message: 'Router exhausted or unknown model' })
       span.end()
-      startChatGeneration({
+      llmTracing.startChatGeneration({
         input: body.messages,
         model: routeCtx.upstreamModel ?? requestModel,
         requestId,
@@ -220,7 +227,7 @@ export function createV1Routes(
     // session cost. Use the router-resolved upstream model, not the client
     // alias (`auto` / `chat-auto`), so Langfuse model-cost grouping matches the
     // provider model that actually generated the tokens.
-    const generationTrace = startChatGeneration({
+    const generationTrace = llmTracing.startChatGeneration({
       input: body.messages,
       model: langfuseModel,
       requestId,
@@ -598,7 +605,7 @@ export function createV1Routes(
       speed: typeof body.speed === 'number' ? body.speed : undefined,
       responseFormat: typeof body.response_format === 'string' ? body.response_format : undefined,
     }
-    const generationTrace = startTtsGeneration({
+    const generationTrace = llmTracing.startTtsGeneration({
       input: ttsInput,
       model: requestModel,
       requestId,

apps/server/src/routes/openai/v1/route.test.ts

@@ -2,6 +2,7 @@ import type { ConfigKVService } from '../../../services/adapters/config-kv'
 import type { BillingService } from '../../../services/domain/billing/billing-service'
 import type { FluxService } from '../../../services/domain/flux'
 import type { LlmRouterService } from '../../../services/domain/llm-router'
+import type { ChatGenerationTrace, TtsGenerationTrace } from '../../../services/domain/llm-tracing'
 import type { RequestLogService } from '../../../services/domain/request-log'
 import type { HonoEnv } from '../../../types/hono'
 
@@ -11,23 +12,6 @@ import { afterAll, beforeEach, describe, expect, it, vi } from 'vitest'
 import { createV1Routes } from '.'
 import { ApiError } from '../../../utils/error'
 
-const tracingSpies = vi.hoisted(() => ({
-  startChatGeneration: vi.fn(() => ({
-    appendStreamChunk: vi.fn(),
-    succeed: vi.fn(),
-    fail: vi.fn(),
-  })),
-  startTtsGeneration: vi.fn(() => ({
-    succeed: vi.fn(),
-    fail: vi.fn(),
-  })),
-}))
-
-vi.mock('../../../services/domain/llm-tracing', () => ({
-  startChatGeneration: tracingSpies.startChatGeneration,
-  startTtsGeneration: tracingSpies.startTtsGeneration,
-}))
-
 function createMockFluxService(flux = 100): FluxService {
   return {
     getFlux: vi.fn(async () => ({ userId: 'user-1', flux })),
@@ -101,6 +85,20 @@ function createMockTtsMeter(unitsPerFlux = 1000) {
   } as any
 }
 
+function createMockLlmTracing() {
+  return {
+    startChatGeneration: vi.fn((): ChatGenerationTrace => ({
+      appendStreamChunk: vi.fn(),
+      succeed: vi.fn(),
+      fail: vi.fn(),
+    })),
+    startTtsGeneration: vi.fn((): TtsGenerationTrace => ({
+      succeed: vi.fn(),
+      fail: vi.fn(),
+    })),
+  }
+}
+
 function createMockLlmRouter(impl?: Partial<LlmRouterService>): LlmRouterService {
   return {
     // Default: forward to globalThis.fetch so existing chat tests that mock
@@ -137,6 +135,7 @@ function createTestApp(
   requestLogService?: RequestLogService,
   ttsMeter?: ReturnType<typeof createMockTtsMeter>,
   llmRouter?: LlmRouterService,
+  llmTracing = createMockLlmTracing(),
 ) {
   const { openaiRoutes, audioRoutes } = createV1Routes(
     fluxService,
@@ -146,6 +145,10 @@ function createTestApp(
     ttsMeter ?? createMockTtsMeter(),
     llmRouter ?? createMockLlmRouter(),
     null,
+    null,
+    null,
+    null,
+    llmTracing,
   )
   const app = new Hono<HonoEnv>()
 
@@ -184,8 +187,7 @@ describe('v1CompletionsRoutes', () => {
   const originalFetch = globalThis.fetch
 
   beforeEach(() => {
-    tracingSpies.startChatGeneration.mockClear()
-    tracingSpies.startTtsGeneration.mockClear()
+    globalThis.fetch = originalFetch
   })
 
   afterAll(() => {
@@ -419,7 +421,8 @@ describe('v1CompletionsRoutes', () => {
           })
         }) as any,
       })
-      const app = createTestApp(createMockFluxService(), createMockConfigKV(), undefined, undefined, undefined, llmRouter)
+      const llmTracing = createMockLlmTracing()
+      const app = createTestApp(createMockFluxService(), createMockConfigKV(), undefined, undefined, undefined, llmRouter, llmTracing)
 
       await app.fetch(
         new Request('http://localhost/api/v1/openai/chat/completions', {
@@ -430,7 +433,7 @@ describe('v1CompletionsRoutes', () => {
         { user: testUser } as any,
       )
 
-      expect(tracingSpies.startChatGeneration).toHaveBeenCalledWith(
+      expect(llmTracing.startChatGeneration).toHaveBeenCalledWith(
         expect.objectContaining({
           model: 'openai/gpt-4o-mini',
           requestId: expect.any(String),
@@ -742,6 +745,11 @@ describe('v1CompletionsRoutes', () => {
     // billing-failed request without a fluxConsumed value), but the
     // failure is now observable instead of hidden by a leaked span.
     it('tTS billing failure closes the span and surfaces error to onError (regression)', async () => {
+      globalThis.fetch = vi.fn(async () => new Response(new Uint8Array([1]), {
+        status: 200,
+        headers: { 'Content-Type': 'audio/mpeg' },
+      }))
+
       const requestLogService = createMockRequestLogService()
       const ttsMeter = createMockTtsMeter()
       // Override accumulate to simulate a Redis INCRBY failure mid-billing.

eslint.config.js

@@ -64,6 +64,21 @@ export default defineConfig({
     'yaml/plain-scalar': 'off',
     'markdown/require-alt-text': 'off',
   },
+}, {
+  files: ['apps/server/**/*.ts'],
+  rules: {
+    'no-restricted-syntax': [
+      'error',
+      {
+        selector: 'CallExpression[callee.type=\'MemberExpression\'][callee.object.name=\'vi\'][callee.property.name=/^(mock|doMock)$/][arguments.0.type=\'Literal\'][arguments.0.value=/^(\\.|@proj-airi\\/|~)/]',
+        message: 'Do not mock internal project modules with vi.mock or vi.doMock. Inject the collaborator through the route, service, or factory boundary and pass a fake or spy in tests.',
+      },
+      {
+        selector: 'CallExpression[callee.type=\'MemberExpression\'][callee.object.name=\'vi\'][callee.property.name=\'hoisted\']',
+        message: 'Do not use vi.hoisted. If a test needs a collaborator spy, expose an explicit dependency injection point instead of hoisting module mocks.',
+      },
+    ],
+  },
 }, {
   ignores: [
     '**/*.md',