refactor: deduplicate demo request check

Author: catruzh1

server/src/controllers/course.controller.ts

@@ -1,12 +1,12 @@
 import type { Request, Response, NextFunction } from 'express'
 import { query } from '../config/database.js'
 import { cache, CACHE_KEYS } from '../config/redis.js'
-import { config } from '../config/env.js'
 import { createError } from '../middleware/error.middleware.js'
 import { COURSES_DIR, loadCourseFromFilesystem, loadCourseMetadata, courseExistsInFilesystem } from '../services/filesystem-loader.js'
 import { loadAppConfig } from '../config/app-config.js'
 import { formatCurrency } from '../utils/currency.js'
 import { formatDate, formatRelativeDate } from '../utils/date.js'
+import { isDemoRequest } from '../utils/demo.js'
 import { stat } from 'fs/promises'
 import path from 'path'
 import type {
@@ -35,11 +35,6 @@ async function attachMyReactions(reviews: ReviewResponse[], userId: number): Pro
     }))
 }
 
-function isDemoRequest(req: Request): boolean {
-    const hasDemoHeader = !!req.headers['x-demo-user']
-    return config.demoMode || (config.nodeEnv !== 'production' && hasDemoHeader)
-}
-
 /**
  * GET /api/courses/featured
  * Returns list of featured/published courses

server/src/controllers/support.controller.ts

@@ -3,6 +3,7 @@ import { query, insert } from '../config/database.js'
 import { createError } from '../middleware/error.middleware.js'
 import { notifyNewSupportMessage } from '../services/support-notifications.service.js'
 import { config } from '../config/env.js'
+import { isDemoRequest } from '../utils/demo.js'
 
 type SenderType = 'user' | 'admin'
 
@@ -58,11 +59,6 @@ interface SupportUserRow {
     has_started?: number | null
 }
 
-function isDemoRequest(req: Request): boolean {
-    const hasDemoHeader = !!req.headers['x-demo-user']
-    return config.demoMode || (config.nodeEnv !== 'production' && hasDemoHeader)
-}
-
 function shouldIncludeDemo(req: Request): boolean {
     return isDemoRequest(req)
 }

server/src/utils/demo.ts

@@ -0,0 +1,7 @@
+import type { Request } from 'express'
+import { config } from '../config/env.js'
+
+export function isDemoRequest(req: Request): boolean {
+    const hasDemoHeader = !!req.headers['x-demo-user']
+    return config.demoMode || (config.nodeEnv !== 'production' && hasDemoHeader)
+}