Use a standard export statement in the web/pdfjs.js file

This removes the only remaining old and non-standard handling of exports in the `web/`-folder, since some initial attempts at outputting JavaScript modules in the builds have identified this file as a potential problem.
While this uses a hard-coded list, for overall simplicity, I don't believe that that's a big problem since:
 - Generating this file automatically would require a bunch more parsing *every single time* that the library is built.
 - The official API-surface doesn't change often enough for this to really impede development in any significant way.
 - The added unit-test helps ensure that this list cannot accidentally become outdated.

test/unit/pdf_spec.js

@@ -23,6 +23,7 @@ import {
   FeatureTest,
   ImageKind,
   InvalidPDFException,
+  isNodeJS,
   MissingPDFException,
   normalizeUnicode,
   OPS,
@@ -66,18 +67,7 @@ import { AnnotationLayer } from "../../src/display/annotation_layer.js";
 import { GlobalWorkerOptions } from "../../src/display/worker_options.js";
 import { XfaLayer } from "../../src/display/xfa_layer.js";
 
-describe("pdfjs_api", function () {
+const expectedAPI = Object.freeze({
-  it("checks that the *official* PDF.js API exposes the expected functionality", async function () {
-    // eslint-disable-next-line no-unsanitized/method
-    const pdfjsAPI = await import(
-      typeof PDFJSDev !== "undefined" && PDFJSDev.test("LIB")
-        ? "../../pdf.js"
-        : "../../src/pdf.js"
-    );
-
-    // The imported Object contains an (automatically) inserted Symbol,
-    // hence we copy the data to allow using a simple comparison below.
-    expect({ ...pdfjsAPI }).toEqual({
   AbortException,
   AnnotationEditorLayer,
   AnnotationEditorParamsType,
@@ -123,5 +113,35 @@ describe("pdfjs_api", function () {
   version,
   XfaLayer,
 });
+
+describe("pdfjs_api", function () {
+  it("checks that the *official* PDF.js API exposes the expected functionality", async function () {
+    // eslint-disable-next-line no-unsanitized/method
+    const pdfjsAPI = await import(
+      typeof PDFJSDev !== "undefined" && PDFJSDev.test("LIB")
+        ? "../../pdf.js"
+        : "../../src/pdf.js"
+    );
+
+    // The imported Object contains an (automatically) inserted Symbol,
+    // hence we copy the data to allow using a simple comparison below.
+    expect({ ...pdfjsAPI }).toEqual(expectedAPI);
+  });
+});
+
+describe("web_pdfjsLib", function () {
+  it("checks that the viewer re-exports the expected API functionality", async function () {
+    if (isNodeJS) {
+      pending("loadScript is not supported in Node.js.");
+    }
+    await loadScript(
+      "../../build/generic/build/pdf.js",
+      /* removeScriptElement = */ true
+    );
+    const webPdfjsLib = await import("../../web/pdfjs.js");
+
+    expect(Object.keys(webPdfjsLib).sort()).toEqual(
+      Object.keys(expectedAPI).sort()
+    );
   });
 });

web/pdfjs.js

@@ -12,8 +12,97 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/* globals module */
 
-"use strict";
+const {
+  AbortException,
+  AnnotationEditorLayer,
+  AnnotationEditorParamsType,
+  AnnotationEditorType,
+  AnnotationEditorUIManager,
+  AnnotationLayer,
+  AnnotationMode,
+  build,
+  CMapCompressionType,
+  createValidAbsoluteUrl,
+  DOMSVGFactory,
+  FeatureTest,
+  getDocument,
+  getFilenameFromUrl,
+  getPdfFilenameFromUrl,
+  getXfaPageViewport,
+  GlobalWorkerOptions,
+  ImageKind,
+  InvalidPDFException,
+  isDataScheme,
+  isPdfFile,
+  loadScript,
+  MissingPDFException,
+  noContextMenu,
+  normalizeUnicode,
+  OPS,
+  PasswordResponses,
+  PDFDataRangeTransport,
+  PDFDateString,
+  PDFWorker,
+  PermissionFlag,
+  PixelsPerInch,
+  PromiseCapability,
+  RenderingCancelledException,
+  renderTextLayer,
+  setLayerDimensions,
+  shadow,
+  SVGGraphics,
+  UnexpectedResponseException,
+  updateTextLayer,
+  Util,
+  VerbosityLevel,
+  version,
+  XfaLayer,
+} = globalThis.pdfjsLib;
 
-module.exports = globalThis.pdfjsLib;
+export {
+  AbortException,
+  AnnotationEditorLayer,
+  AnnotationEditorParamsType,
+  AnnotationEditorType,
+  AnnotationEditorUIManager,
+  AnnotationLayer,
+  AnnotationMode,
+  build,
+  CMapCompressionType,
+  createValidAbsoluteUrl,
+  DOMSVGFactory,
+  FeatureTest,
+  getDocument,
+  getFilenameFromUrl,
+  getPdfFilenameFromUrl,
+  getXfaPageViewport,
+  GlobalWorkerOptions,
+  ImageKind,
+  InvalidPDFException,
+  isDataScheme,
+  isPdfFile,
+  loadScript,
+  MissingPDFException,
+  noContextMenu,
+  normalizeUnicode,
+  OPS,
+  PasswordResponses,
+  PDFDataRangeTransport,
+  PDFDateString,
+  PDFWorker,
+  PermissionFlag,
+  PixelsPerInch,
+  PromiseCapability,
+  RenderingCancelledException,
+  renderTextLayer,
+  setLayerDimensions,
+  shadow,
+  SVGGraphics,
+  UnexpectedResponseException,
+  updateTextLayer,
+  Util,
+  VerbosityLevel,
+  version,
+  XfaLayer,
+};