Bug 1334831 - add an eslint rule to report usage of .parentNode.removeChild when .remove() could be used instead, r=jaws.

.eslintrc.js

@@ -6,6 +6,7 @@ module.exports = {
     "mozilla"
   ],
   "rules": {
+    "mozilla/avoid-removeChild": "error",
     "mozilla/import-globals": "warn",
     "mozilla/no-import-into-var-and-global": "error",
     "mozilla/no-useless-parameters": "error",

tools/lint/docs/linters/eslint-plugin-mozilla.rst

@@ -2,6 +2,11 @@
 Mozilla ESLint Plugin
 =====================
 
+avoid-removeChild
+-----------------
+
+Rejects using element.parentNode.removeChild(element) when element.remove()
+can be used instead.
 
 balanced-listeners
 ------------------

tools/lint/eslint/eslint-plugin-mozilla/lib/index.js

@@ -17,6 +17,7 @@ module.exports = {
     ".xml": require("../lib/processors/xbl-bindings"),
   },
   rules: {
+    "avoid-removeChild": require("../lib/rules/avoid-removeChild"),
     "balanced-listeners": require("../lib/rules/balanced-listeners"),
     "import-browserjs-globals": require("../lib/rules/import-browserjs-globals"),
     "import-globals": require("../lib/rules/import-globals"),
@@ -34,6 +35,7 @@ module.exports = {
     "var-only-at-top-level": require("../lib/rules/var-only-at-top-level")
   },
   rulesConfig: {
+    "avoid-removeChild": 0,
     "balanced-listeners": 0,
     "import-browserjs-globals": 0,
     "import-globals": 0,

tools/lint/eslint/eslint-plugin-mozilla/lib/rules/avoid-removeChild.js

@@ -0,0 +1,43 @@
+/**
+ * @fileoverview Reject using element.parentNode.removeChild(element) when
+ *               element.remove() can be used instead.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * 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/.
+ */
+
+"use strict";
+
+// -----------------------------------------------------------------------------
+// Rule Definition
+// -----------------------------------------------------------------------------
+
+var helpers = require("../helpers");
+
+module.exports = function(context) {
+
+  // ---------------------------------------------------------------------------
+  // Public
+  //  --------------------------------------------------------------------------
+
+  return {
+    "CallExpression": function(node) {
+      let callee = node.callee;
+      if (callee.type !== "MemberExpression" ||
+          callee.property.type !== "Identifier" ||
+          callee.property.name != "removeChild" ||
+          callee.object.type != "MemberExpression" ||
+          callee.object.property.type != "Identifier" ||
+          callee.object.property.name != "parentNode" ||
+          helpers.getASTSource(callee.object.object) !=
+            helpers.getASTSource(node.arguments[0]) ||
+          node.arguments.length != 1) {
+        return;
+      }
+
+      context.report(node, "use element.remove() instead of " +
+                           "element.parentNode.removeChild(element)");
+    }
+  };
+};

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

@@ -1,6 +1,6 @@
 {
   "name": "eslint-plugin-mozilla",
-  "version": "0.2.15",
+  "version": "0.2.16",
   "description": "A collection of rules that help enforce JavaScript coding standard in the Mozilla project.",
   "keywords": [
     "eslint",

tools/lint/eslint/eslint-plugin-mozilla/tests/avoid-removeChild.js

@@ -0,0 +1,37 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+var rule = require("../lib/rules/avoid-removeChild");
+
+//------------------------------------------------------------------------------
+// Tests
+//------------------------------------------------------------------------------
+
+function invalidCode(code) {
+  let message = "use element.remove() instead of " +
+                "element.parentNode.removeChild(element)";
+  return {code: code, errors: [{message: message, type: "CallExpression"}]};
+}
+
+exports.runTest = function(ruleTester) {
+  ruleTester.run("no-useless-removeEventListener", rule, {
+    valid: [
+      "elt.remove();",
+      "elt.parentNode.parentNode.removeChild(elt2.parentNode);",
+      "elt.parentNode.removeChild(elt2);",
+      "elt.removeChild(elt2);"
+    ],
+    invalid: [
+      invalidCode("elt.parentNode.removeChild(elt);"),
+      invalidCode("elt.parentNode.parentNode.removeChild(elt.parentNode);"),
+      invalidCode("$(e).parentNode.removeChild($(e));"),
+      invalidCode("$('e').parentNode.removeChild($('e'));"),
+    ]
+  });
+};