From 0a970ee4434e62ed9ab5f134a9fc86ba8da81247 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Sat, 30 Sep 2023 13:25:47 +0200
Subject: [PATCH] [api-major] Remove the `fallbackWorkerSrc` functionality in
 browsers

The user should *always* provide a correct `GlobalWorkerOptions.workerSrc` value when using the PDF.js library in browser environments. Note that the fallback:
 - Has been deprecated ever since PR 11418, first released in version `2.4.456` over three years ago.
 - Was always a best-effort solution, with no guarantees that it'd actually work correctly.
 - With upcoming changes, w.r.t. outputting JavaScript modules, it'd now be more diffiult to determine the correct value.
---
 src/display/api.js | 27 ++++-----------------------
 1 file changed, 4 insertions(+), 23 deletions(-)

diff --git a/src/display/api.js b/src/display/api.js
index 43300b052..14382074f 100644
--- a/src/display/api.js
+++ b/src/display/api.js
@@ -45,7 +45,6 @@ import {
   SerializableEmpty,
 } from "./annotation_storage.js";
 import {
-  deprecated,
   DOMCanvasFactory,
   DOMCMapReaderFactory,
   DOMFilterFactory,
@@ -1984,7 +1983,6 @@ class LoopbackPort {
 
 const PDFWorkerUtil = {
   isWorkerDisabled: false,
-  fallbackWorkerSrc: null,
   fakeWorkerId: 0,
 };
 if (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) {
@@ -1993,17 +1991,9 @@ if (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) {
     // Workers aren't supported in Node.js, force-disabling them there.
     PDFWorkerUtil.isWorkerDisabled = true;
 
-    PDFWorkerUtil.fallbackWorkerSrc = PDFJSDev.test("LIB")
+    GlobalWorkerOptions.workerSrc ||= PDFJSDev.test("LIB")
       ? "../pdf.worker.js"
       : "./pdf.worker.js";
-  } else if (typeof document === "object") {
-    const pdfjsFilePath = document?.currentScript?.src;
-    if (pdfjsFilePath) {
-      PDFWorkerUtil.fallbackWorkerSrc = pdfjsFilePath.replace(
-        /(\.(?:min\.)?js)(\?.*)?$/i,
-        ".worker$1$2"
-      );
-    }
   }
 
   // Check if URLs have the same origin. For non-HTTP based URLs, returns false.
@@ -2119,7 +2109,7 @@ class PDFWorker {
     // Uint8Array as it arrives on the worker. (Chrome added this with v.15.)
     if (
       !PDFWorkerUtil.isWorkerDisabled &&
-      !PDFWorker._mainThreadWorkerMessageHandler
+      !PDFWorker.#mainThreadWorkerMessageHandler
     ) {
       let { workerSrc } = PDFWorker;
 
@@ -2308,19 +2298,10 @@ class PDFWorker {
     if (GlobalWorkerOptions.workerSrc) {
       return GlobalWorkerOptions.workerSrc;
     }
-    if (
-      (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) &&
-      PDFWorkerUtil.fallbackWorkerSrc !== null
-    ) {
-      if (!isNodeJS) {
-        deprecated('No "GlobalWorkerOptions.workerSrc" specified.');
-      }
-      return PDFWorkerUtil.fallbackWorkerSrc;
-    }
     throw new Error('No "GlobalWorkerOptions.workerSrc" specified.');
   }
 
-  static get _mainThreadWorkerMessageHandler() {
+  static get #mainThreadWorkerMessageHandler() {
     try {
       return globalThis.pdfjsWorker?.WorkerMessageHandler || null;
     } catch {
@@ -2331,7 +2312,7 @@ class PDFWorker {
   // Loads worker code into the main-thread.
   static get _setupFakeWorkerGlobal() {
     const loader = async () => {
-      const mainWorkerMessageHandler = this._mainThreadWorkerMessageHandler;
+      const mainWorkerMessageHandler = this.#mainThreadWorkerMessageHandler;
 
       if (mainWorkerMessageHandler) {
         // The worker was already loaded using e.g. a `<script>` tag.