[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.

src/display/fetch_stream.js

@@ -16,7 +16,7 @@
 import { AbortException, assert, warn } from "../shared/util.js";
 import {
   createHeaders,
-  createResponseStatusError,
+  createResponseError,
   extractFilenameFromHeader,
   getResponseOrigin,
   validateRangeRequestCapabilities,
@@ -127,7 +127,7 @@ class PDFFetchStreamReader {
         stream._responseOrigin = getResponseOrigin(response.url);
 
         if (!validateResponseStatus(response.status)) {
-          throw createResponseStatusError(response.status, url);
+          throw createResponseError(response.status, url);
         }
         this._reader = response.body.getReader();
         this._headersCapability.resolve();
@@ -230,7 +230,7 @@ class PDFFetchStreamRangeReader {
           );
         }
         if (!validateResponseStatus(response.status)) {
-          throw createResponseStatusError(response.status, url);
+          throw createResponseError(response.status, url);
         }
         this._readCapability.resolve();
         this._reader = response.body.getReader();

src/display/network.js

@@ -16,7 +16,7 @@
 import { assert, stringToBytes, warn } from "../shared/util.js";
 import {
   createHeaders,
-  createResponseStatusError,
+  createResponseError,
   extractFilenameFromHeader,
   getResponseOrigin,
   validateRangeRequestCapabilities,
@@ -329,7 +329,7 @@ class PDFNetworkStreamFullRequestReader {
   }
 
   _onError(status) {
-    this._storedError = createResponseStatusError(status, this._url);
+    this._storedError = createResponseError(status, this._url);
     this._headersCapability.reject(this._storedError);
     for (const requestCapability of this._requests) {
       requestCapability.reject(this._storedError);
@@ -454,7 +454,7 @@ class PDFNetworkStreamRangeRequestReader {
   }
 
   _onError(status) {
-    this._storedError ??= createResponseStatusError(status, this._url);
+    this._storedError ??= createResponseError(status, this._url);
     for (const requestCapability of this._requests) {
       requestCapability.reject(this._storedError);
     }

src/display/network_utils.js

@@ -13,11 +13,7 @@
  * limitations under the License.
  */
 
-import {
-  assert,
-  MissingPDFException,
-  UnexpectedResponseException,
-} from "../shared/util.js";
+import { assert, ResponseException } from "../shared/util.js";
 import { getFilenameFromContentDispositionHeader } from "./content_disposition.js";
 import { isPdfFile } from "./display_utils.js";
 
@@ -108,13 +104,11 @@ function extractFilenameFromHeader(responseHeaders) {
   return null;
 }
 
-function createResponseStatusError(status, url) {
-  if (status === 404 || (status === 0 && url.startsWith("file:"))) {
-    return new MissingPDFException('Missing PDF "' + url + '".');
-  }
-  return new UnexpectedResponseException(
+function createResponseError(status, url) {
+  return new ResponseException(
     `Unexpected server response (${status}) while retrieving PDF "${url}".`,
-    status
+    status,
+    /* missing = */ status === 404 || (status === 0 && url.startsWith("file:"))
   );
 }
 
@@ -124,7 +118,7 @@ function validateResponseStatus(status) {
 
 export {
   createHeaders,
-  createResponseStatusError,
+  createResponseError,
   extractFilenameFromHeader,
   getResponseOrigin,
   validateRangeRequestCapabilities,

src/display/node_stream.js

@@ -14,7 +14,8 @@
  */
 /* globals process */
 
-import { AbortException, assert, MissingPDFException } from "../shared/util.js";
+import { AbortException, assert } from "../shared/util.js";
+import { createResponseError } from "./network_utils.js";
 
 if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) {
   throw new Error(
@@ -111,7 +112,7 @@ class PDFNodeStreamFsFullReader {
       },
       error => {
         if (error.code === "ENOENT") {
-          error = new MissingPDFException(`Missing PDF "${this._url}".`);
+          error = createResponseError(/* status = */ 0, this._url.href);
         }
         this._storedError = error;
         this._headersCapability.reject(error);

src/pdf.js

@@ -31,13 +31,12 @@ import {
   FeatureTest,
   ImageKind,
   InvalidPDFException,
-  MissingPDFException,
   normalizeUnicode,
   OPS,
   PasswordResponses,
   PermissionFlag,
+  ResponseException,
   shadow,
-  UnexpectedResponseException,
   Util,
   VerbosityLevel,
 } from "./shared/util.js";
@@ -112,7 +111,6 @@ export {
   InvalidPDFException,
   isDataScheme,
   isPdfFile,
-  MissingPDFException,
   noContextMenu,
   normalizeUnicode,
   OPS,
@@ -124,12 +122,12 @@ export {
   PermissionFlag,
   PixelsPerInch,
   RenderingCancelledException,
+  ResponseException,
   setLayerDimensions,
   shadow,
   stopEvent,
   TextLayer,
   TouchManager,
-  UnexpectedResponseException,
   Util,
   VerbosityLevel,
   version,

src/shared/message_handler.js

@@ -17,9 +17,8 @@ import {
   AbortException,
   assert,
   InvalidPDFException,
-  MissingPDFException,
   PasswordException,
-  UnexpectedResponseException,
+  ResponseException,
   UnknownErrorException,
   unreachable,
 } from "./util.js";
@@ -46,9 +45,8 @@ function wrapReason(ex) {
   if (
     ex instanceof AbortException ||
     ex instanceof InvalidPDFException ||
-    ex instanceof MissingPDFException ||
     ex instanceof PasswordException ||
-    ex instanceof UnexpectedResponseException ||
+    ex instanceof ResponseException ||
     ex instanceof UnknownErrorException
   ) {
     // Avoid re-creating the exception when its type is already correct.
@@ -65,12 +63,10 @@ function wrapReason(ex) {
       return new AbortException(ex.message);
     case "InvalidPDFException":
       return new InvalidPDFException(ex.message);
-    case "MissingPDFException":
-      return new MissingPDFException(ex.message);
     case "PasswordException":
       return new PasswordException(ex.message, ex.code);
-    case "UnexpectedResponseException":
-      return new UnexpectedResponseException(ex.message, ex.status);
+    case "ResponseException":
+      return new ResponseException(ex.message, ex.status, ex.missing);
     case "UnknownErrorException":
       return new UnknownErrorException(ex.message, ex.details);
   }

src/shared/util.js

@@ -501,16 +501,11 @@ class InvalidPDFException extends BaseException {
   }
 }
 
-class MissingPDFException extends BaseException {
-  constructor(msg) {
-    super(msg, "MissingPDFException");
-  }
-}
-
-class UnexpectedResponseException extends BaseException {
-  constructor(msg, status) {
-    super(msg, "UnexpectedResponseException");
+class ResponseException extends BaseException {
+  constructor(msg, status, missing) {
+    super(msg, "ResponseException");
     this.status = status;
+    this.missing = missing;
   }
 }
 
@@ -1161,7 +1156,6 @@ export {
   LINE_DESCENT_FACTOR,
   LINE_FACTOR,
   MAX_IMAGE_SIZE_TO_CACHE,
-  MissingPDFException,
   normalizeUnicode,
   objectFromMap,
   objectSize,
@@ -1171,6 +1165,7 @@ export {
   PasswordResponses,
   PermissionFlag,
   RenderingIntentFlag,
+  ResponseException,
   setVerbosityLevel,
   shadow,
   string32,
@@ -1180,7 +1175,6 @@ export {
   TextRenderingMode,
   toBase64Util,
   toHexUtil,
-  UnexpectedResponseException,
   UnknownErrorException,
   unreachable,
   utf8StringToString,