1 files changed, 24 insertions, 0 deletions
diff --git a/tools/eslint/lib/rules/use-isnan.js b/tools/eslint/lib/rules/use-isnan.js
new file mode 100644
index 0000000000..d7a3f53768
--- /dev/null
+++ b/tools/eslint/lib/rules/use-isnan.js
@@ -0,0 +1,24 @@
+/**
+ * @fileoverview Rule to flag comparisons to the value NaN
+ * @author James Allardice
+ * @copyright 2014 Jordan Harband. All rights reserved.
+ * @copyright 2013 James Allardice. All rights reserved.
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = function (context) {
+
+    return {
+        "BinaryExpression": function (node) {
+            if (/^(?:[<>]|[!=]=)=?$/.test(node.operator) && (node.left.name === "NaN" || node.right.name === "NaN")) {
+                context.report(node, "Use the isNaN function to compare with NaN.");
+            }
+        }
+    };
+
+};