From c4372a3a2b940b940c761dbecb7eaaaed40b9f27 Mon Sep 17 00:00:00 2001
From: hongzhidao <hongzhidao@gmail.com>
Date: Thu, 11 Apr 2019 21:13:03 +0800
Subject: [PATCH] Checking for duplicate function parameter names.

This closes #80 issue on Github.
---
 njs/njs_parser.c         |  6 ++++++
 njs/test/njs_unit_test.c | 21 +++++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/njs/njs_parser.c b/njs/njs_parser.c
index 5a2394f3..d53cfab7 100644
--- a/njs/njs_parser.c
+++ b/njs/njs_parser.c
@@ -837,6 +837,12 @@ njs_parser_lambda_argument(njs_vm_t *vm, njs_parser_t *parser,
         return NJS_TOKEN_ERROR;
     }
 
+    if (arg->index > 0) {
+        njs_parser_syntax_error(vm, parser, "Duplicate parameter names");
+
+        return NJS_TOKEN_ILLEGAL;
+    }
+
     arg->index = index;
 
     ret = njs_name_copy(vm, &arg->name, njs_parser_text(parser));
diff --git a/njs/test/njs_unit_test.c b/njs/test/njs_unit_test.c
index b1903164..ede03192 100644
--- a/njs/test/njs_unit_test.c
+++ b/njs/test/njs_unit_test.c
@@ -5716,6 +5716,27 @@ static njs_unit_test_t  njs_test[] =
                  "binded.length"),
       nxt_string("0") },
 
+    { nxt_string("function f(a,a) { };"),
+      nxt_string("SyntaxError: Duplicate parameter names in 1") },
+
+    { nxt_string("function f(a,b,a) { };"),
+      nxt_string("SyntaxError: Duplicate parameter names in 1") },
+
+    { nxt_string("function f(a, ...a) { };"),
+      nxt_string("SyntaxError: Duplicate parameter names in 1") },
+
+    { nxt_string("(function(a,a) { })"),
+      nxt_string("SyntaxError: Duplicate parameter names in 1") },
+
+    { nxt_string("(function(a,...a) { })"),
+      nxt_string("SyntaxError: Duplicate parameter names in 1") },
+
+    { nxt_string("(function f(a,a) { })"),
+      nxt_string("SyntaxError: Duplicate parameter names in 1") },
+
+    { nxt_string("(function f(a,...a) { })"),
+      nxt_string("SyntaxError: Duplicate parameter names in 1") },
+
     { nxt_string("function f(a,b) { }; f.length"),
       nxt_string("2") },
 
-- 
2.47.3