1 files changed, 61 insertions, 0 deletions
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/avoid-Date-timing.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/avoid-Date-timing.js
new file mode 100644
index 0000000000..ce576e9483
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+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/avoid-Date-timing.js
@@ -0,0 +1,61 @@
+/**
+ * @fileoverview Disallow using Date for timing in performance sensitive code
+ *
+ * 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";
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/avoid-Date-timing.html",
+    },
+    messages: {
+      usePerfNow:
+        "use performance.now() instead of Date.now() for timing measurements",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    return {
+      CallExpression(node) {
+        let callee = node.callee;
+        if (
+          callee.type !== "MemberExpression" ||
+          callee.object.type !== "Identifier" ||
+          callee.object.name !== "Date" ||
+          callee.property.type !== "Identifier" ||
+          callee.property.name !== "now"
+        ) {
+          return;
+        }
+
+        context.report({
+          node,
+          messageId: "usePerfNow",
+        });
+      },
+
+      NewExpression(node) {
+        let callee = node.callee;
+        if (
+          callee.type !== "Identifier" ||
+          callee.name !== "Date" ||
+          node.arguments.length
+        ) {
+          return;
+        }
+
+        context.report({
+          node,
+          messageId: "usePerfNow",
+        });
+      },
+    };
+  },
+};