[api-major] Replace MissingPDFException and UnexpectedResponseException with one exception

These old exceptions have a fair amount of overlap given how/where they are being used, which is likely because they were introduced at different points in time, hence we can shorten and simplify the code by replacing them with a more general `ResponseException` instead.

Besides an error message, the new `ResponseException` instances also include:
 - A numeric `status` field containing the server response status, similar to the old `UnexpectedResponseException`.

 - A boolean `missing` field, to allow easily detecting the situations where `MissingPDFException` was previously thrown.

test/unit/api_spec.js

@@ -20,12 +20,12 @@ import {
   ImageKind,
   InvalidPDFException,
   isNodeJS,
-  MissingPDFException,
   objectSize,
   OPS,
   PasswordException,
   PasswordResponses,
   PermissionFlag,
+  ResponseException,
   UnknownErrorException,
 } from "../../src/shared/util.js";
 import {
@@ -297,7 +297,9 @@ describe("api", function () {
         // Shouldn't get here.
         expect(false).toEqual(true);
       } catch (reason) {
-        expect(reason instanceof MissingPDFException).toEqual(true);
+        expect(reason instanceof ResponseException).toEqual(true);
+        expect(reason.status).toEqual(isNodeJS ? 0 : 404);
+        expect(reason.missing).toEqual(true);
       }
 
       await loadingTask.destroy();

test/unit/network_spec.js

@@ -13,10 +13,7 @@
  * limitations under the License.
  */
 
-import {
-  AbortException,
-  UnexpectedResponseException,
-} from "../../src/shared/util.js";
+import { AbortException, ResponseException } from "../../src/shared/util.js";
 import { PDFNetworkStream } from "../../src/display/network.js";
 import { testCrossOriginRedirects } from "./common_pdfstream_tests.js";
 import { TestPdfsServer } from "./test_utils.js";
@@ -155,8 +152,9 @@ describe("network", function () {
         // Shouldn't get here.
         expect(false).toEqual(true);
       } catch (ex) {
-        expect(ex instanceof UnexpectedResponseException).toEqual(true);
+        expect(ex instanceof ResponseException).toEqual(true);
         expect(ex.status).toEqual(0);
+        expect(ex.missing).toEqual(false);
       }
     }
 

test/unit/network_utils_spec.js

@@ -15,15 +15,12 @@
 
 import {
   createHeaders,
-  createResponseStatusError,
+  createResponseError,
   extractFilenameFromHeader,
   validateRangeRequestCapabilities,
   validateResponseStatus,
 } from "../../src/display/network_utils.js";
-import {
-  MissingPDFException,
-  UnexpectedResponseException,
-} from "../../src/shared/util.js";
+import { ResponseException } from "../../src/shared/util.js";
 
 describe("network_utils", function () {
   describe("createHeaders", function () {
@@ -370,31 +367,28 @@ describe("network_utils", function () {
     });
   });
 
-  describe("createResponseStatusError", function () {
-    it("handles missing PDF file responses", function () {
-      expect(createResponseStatusError(404, "https://foo.com/bar.pdf")).toEqual(
-        new MissingPDFException('Missing PDF "https://foo.com/bar.pdf".')
-      );
+  describe("createResponseError", function () {
+    function testCreateResponseError(url, status, missing) {
+      const error = createResponseError(status, url);
 
-      expect(createResponseStatusError(0, "file://foo.pdf")).toEqual(
-        new MissingPDFException('Missing PDF "file://foo.pdf".')
+      expect(error instanceof ResponseException).toEqual(true);
+      expect(error.message).toEqual(
+        `Unexpected server response (${status}) while retrieving PDF "${url}".`
       );
+      expect(error.status).toEqual(status);
+      expect(error.missing).toEqual(missing);
+    }
+
+    it("handles missing PDF file responses", function () {
+      testCreateResponseError("https://foo.com/bar.pdf", 404, true);
+
+      testCreateResponseError("file://foo.pdf", 0, true);
     });
 
     it("handles unexpected responses", function () {
-      expect(createResponseStatusError(302, "https://foo.com/bar.pdf")).toEqual(
-        new UnexpectedResponseException(
-          "Unexpected server response (302) while retrieving PDF " +
-            '"https://foo.com/bar.pdf".'
-        )
-      );
+      testCreateResponseError("https://foo.com/bar.pdf", 302, false);
 
-      expect(createResponseStatusError(0, "https://foo.com/bar.pdf")).toEqual(
-        new UnexpectedResponseException(
-          "Unexpected server response (0) while retrieving PDF " +
-            '"https://foo.com/bar.pdf".'
-        )
-      );
+      testCreateResponseError("https://foo.com/bar.pdf", 0, false);
     });
   });
 

test/unit/pdf_spec.js

@@ -23,13 +23,12 @@ import {
   ImageKind,
   InvalidPDFException,
   isNodeJS,
-  MissingPDFException,
   normalizeUnicode,
   OPS,
   PasswordResponses,
   PermissionFlag,
+  ResponseException,
   shadow,
-  UnexpectedResponseException,
   Util,
   VerbosityLevel,
 } from "../../src/shared/util.js";
@@ -90,7 +89,6 @@ const expectedAPI = Object.freeze({
   InvalidPDFException,
   isDataScheme,
   isPdfFile,
-  MissingPDFException,
   noContextMenu,
   normalizeUnicode,
   OPS,
@@ -102,12 +100,12 @@ const expectedAPI = Object.freeze({
   PermissionFlag,
   PixelsPerInch,
   RenderingCancelledException,
+  ResponseException,
   setLayerDimensions,
   shadow,
   stopEvent,
   TextLayer,
   TouchManager,
-  UnexpectedResponseException,
   Util,
   VerbosityLevel,
   version,