Bug 1358947 - Make eslint "max-nested-callbacks" rule an error. r=sta…

…ndard8

eslint's default max-nested-callbacks threshold is 10, but now we make it an error. We could further lower the max-nested-callbacks threshold globally to 8, like browser/.eslintrc.js, but that would require adding suppression comments in (two) more .js test files. 10 seems good enough for now since it's the eslint default.

We need to specify max-nested-callbacks in accessible/.eslintrc because it doesn't inherit the mozilla/recommended rules.

Also bump the eslint-plugin-mozilla version because we modified the mozilla/recommended rules.

MozReview-Commit-ID: JA41vsi4U7j

accessible/.eslintrc.js

@@ -13,5 +13,9 @@ module.exports = {
     "dump": true,
     "Services": true,
     "XPCOMUtils": true
+  },
+  "rules": {
+    // Maximum depth callbacks can be nested.
+    "max-nested-callbacks": ["error", 10],
   }
 };

toolkit/components/places/tests/browser/browser_favicon_setAndFetchFaviconForPage_failures.js

@@ -2,6 +2,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+/* eslint max-nested-callbacks: ["warn", 17] */
+
 /**
  * This file tests setAndFetchFaviconForPage when it is called with invalid
  * arguments, and when no favicon is stored for the given arguments.

toolkit/mozapps/extensions/test/browser/browser_bug562797.js

@@ -2,6 +2,8 @@
  * http://creativecommons.org/publicdomain/zero/1.0/
  */
 
+/* eslint max-nested-callbacks: ["warn", 12] */
+
 /**
  * Tests that history navigation works for the add-ons manager.
  */

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

@@ -87,6 +87,9 @@ module.exports = {
     // rule is a better rule to check this.
     "max-depth": "off",
 
+    // Maximum depth callbacks can be nested.
+    "max-nested-callbacks": ["error", 10],
+
     // Always require parenthesis for new calls
     // "new-parens": "error",
 
@@ -135,7 +138,7 @@ module.exports = {
     // Disallow empty destructuring
     "no-empty-pattern": "error",
 
-    // No assiging to exception variable
+    // No assigning to exception variable
     "no-ex-assign": "error",
 
     // No using !! where casting to boolean is already happening

tools/lint/eslint/eslint-plugin-mozilla/package.json

@@ -1,6 +1,6 @@
 {
   "name": "eslint-plugin-mozilla",
-  "version": "0.2.42",
+  "version": "0.2.43",
   "description": "A collection of rules that help enforce JavaScript coding standard in the Mozilla project.",
   "keywords": [
     "eslint",