refactor(pdf): centralize pdf.js runtime configuration and asset resolution

Move pdf.js worker and standard font resolution logic into dedicated
utility functions for improved maintainability and clarity. Replace
inline workerSrc setup with a reusable configurePdfjsNodeRuntime helper.
Update Next.js config to use a shared asset trace list for pdf.js runtime
files, reducing duplication and simplifying future updates.

compute/core/src/pdf/parse.ts

@@ -3,7 +3,7 @@ import type { ParsedPdfDocument, ParsedPdfPage } from '../types/parsed-pdf';
 import { ensureModel } from './model';
 import { runLayoutModel } from './runLayoutModel';
 import { mergeTextWithRegions } from './merge';
-import { resolvePdfjsStandardFontDataUrl } from './pdfjs-runtime';
+import { configurePdfjsNodeRuntime, resolvePdfjsStandardFontDataUrl } from './pdfjs-runtime';
 import { PDF_PARSER_VERSION } from './parser-version';
 import { stitchCrossPageBlocks } from './stitch';
 import { renderPage } from './render';
@@ -36,10 +36,7 @@ export async function parsePdf(input: ParsePdfInput): Promise<ParsedPdfDocument>
   // eslint-disable-next-line @typescript-eslint/ban-ts-comment
   // @ts-ignore
   const pdfjs = await import('pdfjs-dist/legacy/build/pdf.mjs');
-  if (pdfjs.GlobalWorkerOptions) {
-    pdfjs.GlobalWorkerOptions.workerSrc = 'pdfjs-dist/legacy/build/pdf.worker.mjs';
-    pdfjs.GlobalWorkerOptions.workerPort = null;
-  }
+  configurePdfjsNodeRuntime(pdfjs);
   const standardFontDataUrl = resolvePdfjsStandardFontDataUrl();
 
   const loadingTask = pdfjs.getDocument({

compute/core/src/pdf/pdfjs-runtime.ts

@@ -1,14 +1,39 @@
 import fs from 'node:fs';
-import { createRequire } from 'node:module';
 import path from 'node:path';
+import { pathToFileURL } from 'node:url';
 
 let cachedStandardFontDataUrl: string | null = null;
-const require = createRequire(import.meta.url);
+const pdfjsPackageName = 'pdfjs-dist';
+
+function candidatePackageRoots(): string[] {
+  const roots = new Set<string>();
+  let dir = process.cwd();
+
+  for (let i = 0; i < 8; i += 1) {
+    roots.add(path.join(dir, 'node_modules', pdfjsPackageName));
+    const next = path.dirname(dir);
+    if (next === dir) break;
+    dir = next;
+  }
+
+  return [...roots];
+}
+
+function resolvePdfjsPackageFile(relativePath: string): string {
+  const normalizedRelativePath = relativePath.replace(/^\/+/, '');
+  const candidates = candidatePackageRoots().map((root) => path.join(root, normalizedRelativePath));
+  const found = candidates.find((candidate) => fs.existsSync(candidate));
+  if (found) return found;
+
+  throw new Error(
+    `pdfjs-dist file not found: ${normalizedRelativePath}; checked ${candidates.join(', ')}`,
+  );
+}
 
 export function resolvePdfjsStandardFontDataUrl(): string {
   if (cachedStandardFontDataUrl) return cachedStandardFontDataUrl;
 
-  const pdfjsPackageDir = path.dirname(require.resolve('pdfjs-dist/package.json'));
+  const pdfjsPackageDir = path.dirname(resolvePdfjsPackageFile('package.json'));
   const standardFontDir = path.join(pdfjsPackageDir, 'standard_fonts');
 
   if (!fs.existsSync(standardFontDir)) {
@@ -18,3 +43,18 @@ export function resolvePdfjsStandardFontDataUrl(): string {
   cachedStandardFontDataUrl = `${standardFontDir.replace(/\/?$/, '/')}`;
   return cachedStandardFontDataUrl;
 }
+
+export function resolvePdfjsWorkerSrc(): string {
+  return pathToFileURL(resolvePdfjsPackageFile('legacy/build/pdf.worker.mjs')).href;
+}
+
+export function configurePdfjsNodeRuntime(pdfjs: {
+  GlobalWorkerOptions?: {
+    workerSrc?: string;
+    workerPort?: unknown;
+  };
+}): void {
+  if (!pdfjs.GlobalWorkerOptions) return;
+  pdfjs.GlobalWorkerOptions.workerSrc = resolvePdfjsWorkerSrc();
+  pdfjs.GlobalWorkerOptions.workerPort = null;
+}

compute/core/src/pdf/render.ts

@@ -1,5 +1,5 @@
 import type { Canvas } from '@napi-rs/canvas';
-import { resolvePdfjsStandardFontDataUrl } from './pdfjs-runtime';
+import { configurePdfjsNodeRuntime, resolvePdfjsStandardFontDataUrl } from './pdfjs-runtime';
 
 type CanvasRuntime = {
   DOMMatrixCtor: unknown;
@@ -106,11 +106,7 @@ export async function renderPage({
   // eslint-disable-next-line @typescript-eslint/ban-ts-comment
   // @ts-ignore
   const pdfjs = await import('pdfjs-dist/legacy/build/pdf.mjs');
-
-  if (pdfjs.GlobalWorkerOptions) {
-    pdfjs.GlobalWorkerOptions.workerSrc = 'pdfjs-dist/legacy/build/pdf.worker.mjs';
-    pdfjs.GlobalWorkerOptions.workerPort = null;
-  }
+  configurePdfjsNodeRuntime(pdfjs);
 
   const standardFontDataUrl = resolvePdfjsStandardFontDataUrl();
 

next.config.ts

@@ -16,13 +16,18 @@ const securityHeaders = [
 ];
 
 const bundleWorkerCompute = true;
+const pdfjsTraceFiles = [
+  './node_modules/pdfjs-dist/package.json',
+  './node_modules/pdfjs-dist/legacy/build/pdf.mjs',
+  './node_modules/pdfjs-dist/legacy/build/pdf.worker.mjs',
+  './node_modules/pdfjs-dist/standard_fonts/**/*',
+];
 const serverExternalPackages = [
   '@napi-rs/canvas',
   'better-sqlite3',
   'ffmpeg-static',
-  // Keep pdfjs-dist out of the bundle: it resolves its own on-disk assets
-  // (standard_fonts) at runtime via require.resolve, which only works if it
-  // stays a real package in node_modules rather than being inlined.
+  // Keep pdfjs-dist as a real package in node_modules. Server-side preview
+  // rendering resolves pdf.js runtime assets from the filesystem at runtime.
   'pdfjs-dist',
   ...(!bundleWorkerCompute ? ['onnxruntime-node', '@huggingface/tokenizers'] : []),
 ];
@@ -56,19 +61,15 @@ const nextConfig: NextConfig = {
       './node_modules/ffmpeg-static/ffmpeg',
     ],
     '/api/documents/blob/preview/ensure': [
-      // standard_fonts + the worker are loaded by path/specifier, not a static
-      // import, so trace them explicitly. The rest of pdfjs-dist is pulled in
-      // automatically now that it is a server-external package.
-      './node_modules/pdfjs-dist/legacy/build/pdf.worker.mjs',
-      './node_modules/pdfjs-dist/standard_fonts/**/*',
+      // pdf.js runtime assets are resolved through filesystem paths at runtime,
+      // so trace them explicitly for Vercel/standalone serverless bundles.
+      ...pdfjsTraceFiles,
     ],
     '/api/documents/blob/preview/presign': [
-      './node_modules/pdfjs-dist/legacy/build/pdf.worker.mjs',
-      './node_modules/pdfjs-dist/standard_fonts/**/*',
+      ...pdfjsTraceFiles,
     ],
     '/api/documents/blob/preview/fallback': [
-      './node_modules/pdfjs-dist/legacy/build/pdf.worker.mjs',
-      './node_modules/pdfjs-dist/standard_fonts/**/*',
+      ...pdfjsTraceFiles,
     ],
   },
   outputFileTracingExcludes: {