tools: replace closure-linter with eslint

PR-URL: https://github.com/iojs/io.js/pull/1539
Fixes: https://github.com/iojs/io.js/issues/1253
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: Trevor Norris <trev.norris@gmail.com>
Reviewed-By: Roman Reiss <me@silverwind.io>
Reviewed-By: Chris Dickinson <christopher.s.dickinson@gmail.com>
Reviewed-By: Johan Bergström <bugs@bergstroem.nu>
Reviewed-By: Fedor Indutny <fedor.indutny@gmail.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/tools/eslint/lib/rules/no-self-compare.js b/tools/eslint/lib/rules/no-self-compare.js
new file mode 100644
index 0000000000..dc68c50046
--- /dev/null
+++ b/tools/eslint/lib/rules/no-self-compare.js
@@ -0,0 +1,27 @@
+/**
+ * @fileoverview Rule to flag comparison where left part is the same as the right
+ * part.
+ * @author Ilya Volodin
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = function(context) {
+
+    return {
+
+        "BinaryExpression": function(node) {
+            var operators = ["===", "==", "!==", "!=", ">", "<", ">=", "<="];
+            if (operators.indexOf(node.operator) > -1 &&
+                (node.left.type === "Identifier" && node.right.type === "Identifier" && node.left.name === node.right.name ||
+                node.left.type === "Literal" && node.right.type === "Literal" && node.left.value === node.right.value)) {
+                context.report(node, "Comparing to itself is potentially pointless.");
+            }
+        }
+    };
+
+};