Add better support for AppOptions with multiple types (PR 18465 follo…

…w-up)

For options with varying types, see `useSystemFonts`, we're not sufficiently validating the type when setting a new value. This means that for an option that uses `OptionKind.UNDEF_ALLOWED` we'd allow *any* value, which is obviously not the intention.

Hence we instead introduce a new and *optional* `type`-field that allows specifying exactly which types are valid when multiple ones are supported.

*Note:* This obviously didn't occur to me until after PR 18465 landed, sorry about that!

web/app_options.js

@@ -55,10 +55,18 @@ const OptionKind = {
   API: 0x04,
   WORKER: 0x08,
   EVENT_DISPATCH: 0x10,
-  UNDEF_ALLOWED: 0x20,
   PREFERENCE: 0x80,
 };
 
+// Should only be used with options that allow multiple types.
+const Type = {
+  BOOLEAN: 0x01,
+  NUMBER: 0x02,
+  OBJECT: 0x04,
+  STRING: 0x08,
+  UNDEFINED: 0x10,
+};
+
 /**
  * NOTE: These options are used to generate the `default_preferences.json` file,
  *       see `OptionKind.PREFERENCE`, hence the values below must use only
@@ -405,7 +413,8 @@ const defaultOptions = {
     )
       ? false
       : undefined,
-    kind: OptionKind.API + OptionKind.UNDEF_ALLOWED,
+    kind: OptionKind.API,
+    type: Type.BOOLEAN + Type.UNDEFINED,
   },
   verbosity: {
     /** @type {number} */
@@ -484,7 +493,7 @@ if (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) {
 if (typeof PDFJSDev === "undefined" || PDFJSDev.test("TESTING || LIB")) {
   // Ensure that the `defaultOptions` are correctly specified.
   for (const name in defaultOptions) {
-    const { value, kind } = defaultOptions[name];
+    const { value, kind, type } = defaultOptions[name];
 
     if (kind & OptionKind.PREFERENCE) {
       if (kind === OptionKind.PREFERENCE) {
@@ -493,9 +502,9 @@ if (typeof PDFJSDev === "undefined" || PDFJSDev.test("TESTING || LIB")) {
       if (kind & OptionKind.BROWSER) {
         throw new Error(`Cannot mix "PREFERENCE" and "BROWSER" kind: ${name}`);
       }
-      if (kind & OptionKind.UNDEF_ALLOWED) {
+      if (type !== undefined) {
         throw new Error(
-          `Cannot allow \`undefined\` value for "PREFERENCE" kind: ${name}`
+          `Cannot have \`type\`-field for "PREFERENCE" kind: ${name}`
         );
       }
       if (typeof compatParams === "object" && compatParams.has(name)) {
@@ -512,9 +521,9 @@ if (typeof PDFJSDev === "undefined" || PDFJSDev.test("TESTING || LIB")) {
         throw new Error(`Invalid value for "PREFERENCE" kind: ${name}`);
       }
     } else if (kind & OptionKind.BROWSER) {
-      if (kind & OptionKind.UNDEF_ALLOWED) {
+      if (type !== undefined) {
         throw new Error(
-          `Cannot allow \`undefined\` value for "BROWSER" kind: ${name}`
+          `Cannot have \`type\`-field for "BROWSER" kind: ${name}`
         );
       }
       if (typeof compatParams === "object" && compatParams.has(name)) {
@@ -565,8 +574,7 @@ class AppOptions {
       !defaultOpt ||
       !(
         typeof value === typeof defaultOpt.value ||
-        (defaultOpt.kind & OptionKind.UNDEF_ALLOWED &&
-          (value === undefined || defaultOpt.value === undefined))
+        Type[(typeof value).toUpperCase()] & defaultOpt.type
       )
     ) {
       return;
@@ -585,8 +593,7 @@ class AppOptions {
         !defaultOpt ||
         !(
           typeof userOpt === typeof defaultOpt.value ||
-          (defaultOpt.kind & OptionKind.UNDEF_ALLOWED &&
-            (userOpt === undefined || defaultOpt.value === undefined))
+          Type[(typeof userOpt).toUpperCase()] & defaultOpt.type
         )
       ) {
         continue;