Remove PDFWorkerUtil and move its contents into PDFWorker instead

This is possible thanks to features, i.e. private fields and in particular static initialization blocks, that didn't exist back when we started using classes in the code-base.

src/display/api.js

@@ -1998,47 +1998,6 @@ class LoopbackPort {
  *   the constants from {@link VerbosityLevel} should be used.
  */
 
-const PDFWorkerUtil = {
-  isWorkerDisabled: false,
-  fakeWorkerId: 0,
-};
-if (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) {
-  if (isNodeJS) {
-    // Workers aren't supported in Node.js, force-disabling them there.
-    PDFWorkerUtil.isWorkerDisabled = true;
-
-    GlobalWorkerOptions.workerSrc ||= PDFJSDev.test("LIB")
-      ? "../pdf.worker.js"
-      : "./pdf.worker.mjs";
-  }
-
-  // Check if URLs have the same origin. For non-HTTP based URLs, returns false.
-  PDFWorkerUtil.isSameOrigin = function (baseUrl, otherUrl) {
-    let base;
-    try {
-      base = new URL(baseUrl);
-      if (!base.origin || base.origin === "null") {
-        return false; // non-HTTP url
-      }
-    } catch {
-      return false;
-    }
-
-    const other = new URL(otherUrl, base);
-    return base.origin === other.origin;
-  };
-
-  PDFWorkerUtil.createCDNWrapper = function (url) {
-    // We will rely on blob URL's property to specify origin.
-    // We want this function to fail in case if createObjectURL or Blob do not
-    // exist or fail for some reason -- our Worker creation will fail anyway.
-    const wrapper = `await import("${url}");`;
-    return URL.createObjectURL(
-      new Blob([wrapper], { type: "text/javascript" })
-    );
-  };
-}
-
 /**
  * PDF.js web worker abstraction that controls the instantiation of PDF
  * documents. Message handlers are used to pass information from the main
@@ -2048,8 +2007,52 @@ if (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) {
  * @param {PDFWorkerParameters} params - The worker initialization parameters.
  */
 class PDFWorker {
+  static #fakeWorkerId = 0;
+
+  static #isWorkerDisabled = false;
+
   static #workerPorts;
 
+  static {
+    if (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) {
+      if (isNodeJS) {
+        // Workers aren't supported in Node.js, force-disabling them there.
+        this.#isWorkerDisabled = true;
+
+        GlobalWorkerOptions.workerSrc ||= PDFJSDev.test("LIB")
+          ? "../pdf.worker.js"
+          : "./pdf.worker.mjs";
+      }
+
+      // Check if URLs have the same origin. For non-HTTP based URLs, returns
+      // false.
+      this._isSameOrigin = (baseUrl, otherUrl) => {
+        let base;
+        try {
+          base = new URL(baseUrl);
+          if (!base.origin || base.origin === "null") {
+            return false; // non-HTTP url
+          }
+        } catch {
+          return false;
+        }
+        const other = new URL(otherUrl, base);
+        return base.origin === other.origin;
+      };
+
+      this._createCDNWrapper = url => {
+        // We will rely on blob URL's property to specify origin.
+        // We want this function to fail in case if createObjectURL or Blob do
+        // not exist or fail for some reason -- our Worker creation will fail
+        // anyway.
+        const wrapper = `await import("${url}");`;
+        return URL.createObjectURL(
+          new Blob([wrapper], { type: "text/javascript" })
+        );
+      };
+    }
+  }
+
   constructor({
     name = null,
     port = null,
@@ -2138,7 +2141,7 @@ class PDFWorker {
     // Right now, the requirement is, that an Uint8Array is still an
     // Uint8Array as it arrives on the worker.
     if (
-      PDFWorkerUtil.isWorkerDisabled ||
+      PDFWorker.#isWorkerDisabled ||
       PDFWorker.#mainThreadWorkerMessageHandler
     ) {
       this._setupFakeWorker();
@@ -2152,9 +2155,9 @@ class PDFWorker {
       if (
         typeof PDFJSDev !== "undefined" &&
         PDFJSDev.test("GENERIC") &&
-        !PDFWorkerUtil.isSameOrigin(window.location.href, workerSrc)
+        !PDFWorker._isSameOrigin(window.location.href, workerSrc)
       ) {
-        workerSrc = PDFWorkerUtil.createCDNWrapper(
+        workerSrc = PDFWorker._createCDNWrapper(
           new URL(workerSrc, window.location).href
         );
       }
@@ -2234,9 +2237,9 @@ class PDFWorker {
   }
 
   _setupFakeWorker() {
-    if (!PDFWorkerUtil.isWorkerDisabled) {
+    if (!PDFWorker.#isWorkerDisabled) {
       warn("Setting up fake worker.");
-      PDFWorkerUtil.isWorkerDisabled = true;
+      PDFWorker.#isWorkerDisabled = true;
     }
 
     PDFWorker._setupFakeWorkerGlobal
@@ -2249,7 +2252,7 @@ class PDFWorker {
         this._port = port;
 
         // All fake workers use the same port, making id unique.
-        const id = `fake${PDFWorkerUtil.fakeWorkerId++}`;
+        const id = `fake${PDFWorker.#fakeWorkerId++}`;
 
         // If the main thread is our worker, setup the handling for the
         // messages -- the main thread sends to it self.
@@ -3470,7 +3473,6 @@ export {
   PDFDocumentProxy,
   PDFPageProxy,
   PDFWorker,
-  PDFWorkerUtil,
   RenderTask,
   version,
 };

test/unit/api_spec.js

@@ -43,7 +43,6 @@ import {
   PDFDocumentProxy,
   PDFPageProxy,
   PDFWorker,
-  PDFWorkerUtil,
   RenderTask,
 } from "../../src/display/api.js";
 import {
@@ -929,6 +928,31 @@ describe("api", function () {
       expect(typeof workerSrc).toEqual("string");
       expect(workerSrc).toEqual(GlobalWorkerOptions.workerSrc);
     });
+
+    describe("isSameOrigin", function () {
+      it("handles invalid base URLs", function () {
+        // The base URL is not valid.
+        expect(PDFWorker._isSameOrigin("/foo", "/bar")).toEqual(false);
+
+        // The base URL has no origin.
+        expect(PDFWorker._isSameOrigin("blob:foo", "/bar")).toEqual(false);
+      });
+
+      it("correctly checks if the origin of both URLs matches", function () {
+        expect(
+          PDFWorker._isSameOrigin(
+            "https://www.mozilla.org/foo",
+            "https://www.mozilla.org/bar"
+          )
+        ).toEqual(true);
+        expect(
+          PDFWorker._isSameOrigin(
+            "https://www.mozilla.org/foo",
+            "https://www.example.com/bar"
+          )
+        ).toEqual(false);
+      });
+    });
   });
 
   describe("GlobalWorkerOptions", function () {
@@ -4885,33 +4909,4 @@ Caron Broadcasting, Inc., an Ohio corporation (“Lessee”).`)
       }
     );
   });
-
-  describe("PDFWorkerUtil", function () {
-    describe("isSameOrigin", function () {
-      const { isSameOrigin } = PDFWorkerUtil;
-
-      it("handles invalid base URLs", function () {
-        // The base URL is not valid.
-        expect(isSameOrigin("/foo", "/bar")).toEqual(false);
-
-        // The base URL has no origin.
-        expect(isSameOrigin("blob:foo", "/bar")).toEqual(false);
-      });
-
-      it("correctly checks if the origin of both URLs matches", function () {
-        expect(
-          isSameOrigin(
-            "https://www.mozilla.org/foo",
-            "https://www.mozilla.org/bar"
-          )
-        ).toEqual(true);
-        expect(
-          isSameOrigin(
-            "https://www.mozilla.org/foo",
-            "https://www.example.com/bar"
-          )
-        ).toEqual(false);
-      });
-    });
-  });
 });