1 files changed, 43 insertions, 0 deletions
diff --git a/tools/eslint/lib/rules/func-style.js b/tools/eslint/lib/rules/func-style.js
new file mode 100644
index 0000000000..f54350e765
--- /dev/null
+++ b/tools/eslint/lib/rules/func-style.js
@@ -0,0 +1,43 @@
+/**
+ * @fileoverview Rule to enforce a particular function style
+ * @author Nicholas C. Zakas
+ * @copyright 2013 Nicholas C. Zakas. All rights reserved.
+ */
+"use strict";
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = function(context) {
+
+    var style = context.options[0],
+        enforceDeclarations = (style === "declaration");
+
+    return {
+
+        "FunctionDeclaration": function(node) {
+            if (!enforceDeclarations) {
+                context.report(node, "Expected a function expression.");
+            }
+        },
+
+        "FunctionExpression": function() {
+            var parent = context.getAncestors().pop();
+
+            if (enforceDeclarations && parent.type === "VariableDeclarator") {
+                context.report(parent, "Expected a function declaration.");
+            }
+        },
+
+        "ArrowFunctionExpression": function() {
+            var parent = context.getAncestors().pop();
+
+            if (enforceDeclarations && parent.type === "VariableDeclarator") {
+                context.report(parent, "Expected a function declaration.");
+            }
+        }
+
+    };
+
+};