Re-factor the BaseException.name handling, and clean-up some code

Once we're finally able to get rid of SystemJS, which is unfortunately still blocked on [bug 1247687](https://bugzilla.mozilla.org/show_bug.cgi?id=1247687), we might also want to clean-up (or even completely remove) the `BaseException` abstraction and simply extend `Error` directly instead.

At that point we'd need to (explicitly) set the `name` on each class anyway, so this patch is essentially preparing for future clean-up. Furthermore, after the `BaseException` abstraction was added there's been *multiple* issues filed about third-party minification breaking our code since `this.constructor.name` is not guaranteed to always do what you intended.

While hard-coding the strings indeed feels quite unfortunate, it's likely the "best" solution to avoid the problem described above.

src/core/core_utils.js

@@ -52,17 +52,29 @@ function getArrayLookupTableFactory(initializer) {
 
 class MissingDataException extends BaseException {
   constructor(begin, end) {
-    super(`Missing data [${begin}, ${end})`);
+    super(`Missing data [${begin}, ${end})`, "MissingDataException");
     this.begin = begin;
     this.end = end;
   }
 }
 
-class ParserEOFException extends BaseException {}
+class ParserEOFException extends BaseException {
+  constructor(msg) {
+    super(msg, "ParserEOFException");
+  }
+}
 
-class XRefEntryException extends BaseException {}
+class XRefEntryException extends BaseException {
+  constructor(msg) {
+    super(msg, "XRefEntryException");
+  }
+}
 
-class XRefParseException extends BaseException {}
+class XRefParseException extends BaseException {
+  constructor(msg) {
+    super(msg, "XRefParseException");
+  }
+}
 
 /**
  * Get the value of an inheritable property.

src/core/jbig2.js

@@ -20,7 +20,7 @@ import { CCITTFaxDecoder } from "./ccitt.js";
 
 class Jbig2Error extends BaseException {
   constructor(msg) {
-    super(`JBIG2 error: ${msg}`);
+    super(`JBIG2 error: ${msg}`, "Jbig2Error");
   }
 }
 

src/core/jpg.js

@@ -18,18 +18,22 @@ import { readUint16 } from "./core_utils.js";
 
 class JpegError extends BaseException {
   constructor(msg) {
-    super(`JPEG error: ${msg}`);
+    super(`JPEG error: ${msg}`, "JpegError");
   }
 }
 
 class DNLMarkerError extends BaseException {
   constructor(message, scanLines) {
-    super(message);
+    super(message, "DNLMarkerError");
     this.scanLines = scanLines;
   }
 }
 
-class EOIMarkerError extends BaseException {}
+class EOIMarkerError extends BaseException {
+  constructor(msg) {
+    super(msg, "EOIMarkerError");
+  }
+}
 
 /**
  * This code was forked from https://github.com/notmasteryet/jpgjs.

src/core/jpx.js

@@ -19,7 +19,7 @@ import { ArithmeticDecoder } from "./arithmetic_decoder.js";
 
 class JpxError extends BaseException {
   constructor(msg) {
-    super(`JPX error: ${msg}`);
+    super(`JPX error: ${msg}`, "JpxError");
   }
 }
 

src/display/api.js

@@ -2565,17 +2565,8 @@ class WorkerTransport {
         case "UnknownErrorException":
           reason = new UnknownErrorException(ex.message, ex.details);
           break;
-      }
+        default:
-      if (!(reason instanceof Error)) {
+          unreachable("DocException - expected a valid Error.");
-        const msg = "DocException - expected a valid Error.";
-        if (
-          typeof PDFJSDev === "undefined" ||
-          PDFJSDev.test("!PRODUCTION || TESTING")
-        ) {
-          unreachable(msg);
-        } else {
-          warn(msg);
-        }
       }
       loadingTask._capability.reject(reason);
     });

src/display/display_utils.js

@@ -300,7 +300,7 @@ class PageViewport {
 
 class RenderingCancelledException extends BaseException {
   constructor(msg, type) {
-    super(msg);
+    super(msg, "RenderingCancelledException");
     this.type = type;
   }
 }

src/shared/message_handler.js

@@ -20,6 +20,7 @@ import {
   MissingPDFException,
   UnexpectedResponseException,
   UnknownErrorException,
+  warn,
 } from "./util.js";
 
 const CallbackKind = {
@@ -41,19 +42,22 @@ const StreamKind = {
 };
 
 function wrapReason(reason) {
+  if (
+    !(
+      reason instanceof Error ||
+      (typeof reason === "object" && reason !== null)
+    )
+  ) {
     if (
       typeof PDFJSDev === "undefined" ||
       PDFJSDev.test("!PRODUCTION || TESTING")
     ) {
-    assert(
+      throw new Error(
-      reason instanceof Error ||
-        (typeof reason === "object" && reason !== null),
         'wrapReason: Expected "reason" to be a (possibly cloned) Error.'
       );
-  } else {
-    if (typeof reason !== "object" || reason === null) {
-      return reason;
     }
+    warn('wrapReason: Expected "reason" to be a (possibly cloned) Error.');
+    return reason;
   }
   switch (reason.name) {
     case "AbortException":

src/shared/util.js

@@ -459,12 +459,12 @@ function shadow(obj, prop, value) {
  */
 const BaseException = (function BaseExceptionClosure() {
   // eslint-disable-next-line no-shadow
-  function BaseException(message) {
+  function BaseException(message, name) {
     if (this.constructor === BaseException) {
       unreachable("Cannot initialize BaseException.");
     }
     this.message = message;
-    this.name = this.constructor.name;
+    this.name = name;
   }
   BaseException.prototype = new Error();
   BaseException.constructor = BaseException;
@@ -474,25 +474,33 @@ const BaseException = (function BaseExceptionClosure() {
 
 class PasswordException extends BaseException {
   constructor(msg, code) {
-    super(msg);
+    super(msg, "PasswordException");
     this.code = code;
   }
 }
 
 class UnknownErrorException extends BaseException {
   constructor(msg, details) {
-    super(msg);
+    super(msg, "UnknownErrorException");
     this.details = details;
   }
 }
 
-class InvalidPDFException extends BaseException {}
+class InvalidPDFException extends BaseException {
+  constructor(msg) {
+    super(msg, "InvalidPDFException");
+  }
+}
 
-class MissingPDFException extends BaseException {}
+class MissingPDFException extends BaseException {
+  constructor(msg) {
+    super(msg, "MissingPDFException");
+  }
+}
 
 class UnexpectedResponseException extends BaseException {
   constructor(msg, status) {
-    super(msg);
+    super(msg, "UnexpectedResponseException");
     this.status = status;
   }
 }
@@ -500,12 +508,20 @@ class UnexpectedResponseException extends BaseException {
 /**
  * Error caused during parsing PDF data.
  */
-class FormatError extends BaseException {}
+class FormatError extends BaseException {
+  constructor(msg) {
+    super(msg, "FormatError");
+  }
+}
 
 /**
  * Error used to indicate task cancellation.
  */
-class AbortException extends BaseException {}
+class AbortException extends BaseException {
+  constructor(msg) {
+    super(msg, "AbortException");
+  }
+}
 
 const NullCharactersRegExp = /\x00/g;