Bug 1745030 - Improve structure and documentation around globals defi…

…ned in eslint-plugin-mozilla and add structuredClone. r=Gijs

Differential Revision: https://phabricator.services.mozilla.com/D133357

tools/lint/eslint/eslint-plugin-mozilla/lib/configs/recommended.js

@@ -21,31 +21,31 @@ module.exports = {
   extends: ["eslint:recommended", "plugin:prettier/recommended"],
 
   globals: {
+    // These are all specific to Firefox unless otherwise stated.
     Cc: false,
-    // Specific to Firefox (Chrome code only).
     ChromeUtils: false,
     Ci: false,
     Components: false,
     Cr: false,
     Cu: false,
     Debugger: false,
     InstallTrigger: false,
-    // Specific to Firefox
     // https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/InternalError
     InternalError: true,
-    Intl: false,
-    SharedArrayBuffer: false,
-    StopIteration: false,
+    // https://developer.mozilla.org/docs/Web/API/Window/dump
     dump: true,
     // Override the "browser" env definition of "location" to allow writing as it
     // is a writeable property.
     // See https://bugzilla.mozilla.org/show_bug.cgi?id=1509270#c1 for more information.
     location: true,
     openDialog: false,
-    saveStack: false,
+    // https://developer.mozilla.org/docs/Web/API/Window/sizeToContent
     sizeToContent: false,
-    // Specific to Firefox
-    // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/uneval
+    // structuredClone is a new global that only Firefox has currently and so isn't
+    // in ESLint's globals yet.
+    // https://developer.mozilla.org/docs/Web/API/structuredClone
+    structuredClone: false,
+    // https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/uneval
     uneval: false,
   },
 
@@ -58,6 +58,11 @@ module.exports = {
         "mozilla/jsm": true,
       },
       files: ["**/*.jsm", "**/*.jsm.js"],
+      globals: {
+        // Intl is defined in the browser environment, but that's disabled
+        // for jsms, add it here manually.
+        Intl: false,
+      },
       rules: {
         "mozilla/mark-exported-symbols-as-used": "error",
         // TODO: Bug 1575506 turn `builtinGlobals` on here.

tools/lint/eslint/eslint-plugin-mozilla/lib/environments/xpcshell.js

@@ -32,6 +32,7 @@ const extraGlobals = [
   "byteSize",
   "gc",
   "gczeal",
+  "saveStack",
 ];
 
 module.exports = getScriptGlobals(