fix: keep tenant thumbnail paths in production manuals render

app/manuals/page.tsx

@@ -1,8 +1,7 @@
 export const dynamic = "force-dynamic"
 
 import { createHash } from "node:crypto"
-import { existsSync } from "fs"
-import { join } from "path"
+import { existsSync } from "node:fs"
 import { Metadata } from "next"
 import { headers } from "next/headers"
 import { businessConfig } from "@/lib/seo-config"
@@ -13,6 +12,7 @@ import { selectManualsForSite } from "@/lib/manuals-site-selection"
 import { generateSEOMetadata, generateStructuredData } from "@/lib/seo"
 import { getManualsThumbnailsRoot } from "@/lib/manuals-paths"
 import { resolveManualsTenantDomain } from "@/lib/manuals-tenant"
+import { sanitizeManualThumbnailsForRuntime } from "@/lib/manuals-render-safety"
 
 export const metadata: Metadata = generateSEOMetadata({
   title: "Vending Machine Manuals | Rocky Mountain Vending",
@@ -83,20 +83,10 @@ export default async function ManualsPage() {
     )
   }
 
-  // Hide broken local thumbnails so the public manuals page doesn't spam 404s.
-  const thumbnailsRoot = getManualsThumbnailsRoot()
-  manuals = manuals.map((manual) => {
-    if (!manual.thumbnailUrl || /^https?:\/\//i.test(manual.thumbnailUrl)) {
-      return manual
-    }
-
-    const relativeThumbnailPath = manual.thumbnailUrl.includes("/thumbnails/")
-      ? manual.thumbnailUrl.replace(/^.*\/thumbnails\//, "")
-      : manual.thumbnailUrl
-
-    return existsSync(join(thumbnailsRoot, relativeThumbnailPath))
-      ? manual
-      : { ...manual, thumbnailUrl: undefined }
+  manuals = sanitizeManualThumbnailsForRuntime(manuals, {
+    isLocalDevelopment,
+    thumbnailsRoot: getManualsThumbnailsRoot(),
+    fileExists: existsSync,
   })
 
   // Generate structured data for SEO

lib/manuals-render-safety.ts

@@ -0,0 +1,33 @@
+import { join } from "node:path"
+import type { Manual } from "@/lib/manuals-types"
+
+type ThumbnailSanitizeOptions = {
+  isLocalDevelopment: boolean
+  thumbnailsRoot: string
+  fileExists?: (path: string) => boolean
+}
+
+export function sanitizeManualThumbnailsForRuntime(
+  manuals: Manual[],
+  options: ThumbnailSanitizeOptions
+): Manual[] {
+  if (!options.isLocalDevelopment) {
+    return manuals
+  }
+
+  const fileExists = options.fileExists ?? (() => false)
+
+  return manuals.map((manual) => {
+    if (!manual.thumbnailUrl || /^https?:\/\//i.test(manual.thumbnailUrl)) {
+      return manual
+    }
+
+    const relativeThumbnailPath = manual.thumbnailUrl.includes("/thumbnails/")
+      ? manual.thumbnailUrl.replace(/^.*\/thumbnails\//, "")
+      : manual.thumbnailUrl
+
+    return fileExists(join(options.thumbnailsRoot, relativeThumbnailPath))
+      ? manual
+      : { ...manual, thumbnailUrl: undefined }
+  })
+}