1 files changed, 64 insertions, 0 deletions
diff --git a/tools/eslint/lib/rules/default-case.js b/tools/eslint/lib/rules/default-case.js
new file mode 100644
index 0000000000..da0da1ad7d
--- /dev/null
+++ b/tools/eslint/lib/rules/default-case.js
@@ -0,0 +1,64 @@
+/**
+ * @fileoverview require default case in switch statements
+ * @author Aliaksei Shytkin
+ */
+"use strict";
+
+var COMMENT_VALUE = "no default";
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = function(context) {
+
+    //--------------------------------------------------------------------------
+    // Helpers
+    //--------------------------------------------------------------------------
+
+    /**
+     * Shortcut to get last element of array
+     * @param  {*[]} collection Array
+     * @returns {*} Last element
+     */
+    function last(collection) {
+        return collection[collection.length - 1];
+    }
+
+    //--------------------------------------------------------------------------
+    // Public
+    //--------------------------------------------------------------------------
+
+    return {
+
+        "SwitchStatement": function(node) {
+
+            if (!node.cases.length) {
+                // skip check of empty switch because there is no easy way
+                // to extract comments inside it now
+                return;
+            }
+
+            var hasDefault = node.cases.some(function(v) {
+                return v.test === null;
+            });
+
+            if (!hasDefault) {
+
+                var comment;
+                var comments;
+
+                var lastCase = last(node.cases);
+                comments = context.getComments(lastCase).trailing;
+
+                if (comments.length) {
+                    comment = last(comments);
+                }
+
+                if (!comment || comment.value.trim() !== COMMENT_VALUE) {
+                    context.report(node, "Expected a default case.");
+                }
+            }
+        }
+    };
+};