1 files changed, 67 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..4f06390189
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+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/avoid-Date-timing.js
@@ -0,0 +1,67 @@
+/**
+ * @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";
+
+// -----------------------------------------------------------------------------
+// Rule Definition
+// -----------------------------------------------------------------------------
+
+module.exports = {
+  meta: {
+    docs: {
+      description: "disallow use of Date for timing measurements",
+      category: "Best Practices",
+    },
+    schema: [],
+  },
+
+  // ---------------------------------------------------------------------------
+  // Public
+  //  --------------------------------------------------------------------------
+
+  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,
+          "use performance.now() instead of Date.now() for timing " +
+            "measurements"
+        );
+      },
+
+      NewExpression(node) {
+        let callee = node.callee;
+        if (
+          callee.type !== "Identifier" ||
+          callee.name !== "Date" ||
+          node.arguments.length > 0
+        ) {
+          return;
+        }
+
+        context.report(
+          node,
+          "use performance.now() instead of new Date() for timing " +
+            "measurements"
+        );
+      },
+    };
+  },
+};