From 22eabd0e0be2579a3c497c79e98921a2cfc8493c Mon Sep 17 00:00:00 2001
From: Zoltan Herczeg <zherczeg.u-szeged@partner.samsung.com>
Date: Thu, 16 Jan 2020 17:00:49 +0100
Subject: [PATCH] Allow an extra comma before the end of a function call.
 (#3520)

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com
---
 jerry-core/parser/js/js-parser-expr.c | 69 +++++++++++++++++----------
 tests/jerry/es2015/function-call.js   | 38 +++++++++++++++
 2 files changed, 83 insertions(+), 24 deletions(-)
 create mode 100644 tests/jerry/es2015/function-call.js

diff --git a/jerry-core/parser/js/js-parser-expr.c b/jerry-core/parser/js/js-parser-expr.c
index 167cc0d42..44d57dd86 100644
--- a/jerry-core/parser/js/js-parser-expr.c
+++ b/jerry-core/parser/js/js-parser-expr.c
@@ -1894,43 +1894,64 @@ parser_process_unary_expression (parser_context_t *context_p, /**< context */
         }
         else
         {
-#endif /* ENABLED (JERRY_ES2015) */
           lexer_next_token (context_p);
 
-          if (context_p->token.type != LEXER_RIGHT_PAREN)
+          while (context_p->token.type != LEXER_RIGHT_PAREN)
           {
-            while (true)
+            if (++call_arguments > CBC_MAXIMUM_BYTE_VALUE)
             {
-              if (++call_arguments > CBC_MAXIMUM_BYTE_VALUE)
-              {
-                parser_raise_error (context_p, PARSER_ERR_ARGUMENT_LIMIT_REACHED);
-              }
+              parser_raise_error (context_p, PARSER_ERR_ARGUMENT_LIMIT_REACHED);
+            }
 
-#if ENABLED (JERRY_ES2015)
-              if (context_p->token.type == LEXER_THREE_DOTS)
-              {
-                has_spread_element = true;
-                call_arguments++;
-                parser_emit_cbc_ext (context_p, CBC_EXT_PUSH_SPREAD_ELEMENT);
-                lexer_next_token (context_p);
-              }
-#endif /* ENABLED (JERRY_ES2015) */
-
-              parser_parse_expression (context_p, PARSE_EXPR_NO_COMMA);
-
-              if (context_p->token.type != LEXER_COMMA)
-              {
-                break;
-              }
+            if (context_p->token.type == LEXER_THREE_DOTS)
+            {
+              has_spread_element = true;
+              call_arguments++;
+              parser_emit_cbc_ext (context_p, CBC_EXT_PUSH_SPREAD_ELEMENT);
               lexer_next_token (context_p);
             }
 
+            parser_parse_expression (context_p, PARSE_EXPR_NO_COMMA);
+
+            if (context_p->token.type == LEXER_COMMA)
+            {
+              lexer_next_token (context_p);
+              continue;
+            }
+
             if (context_p->token.type != LEXER_RIGHT_PAREN)
             {
               parser_raise_error (context_p, PARSER_ERR_RIGHT_PAREN_EXPECTED);
             }
+
+            break;
+          }
+        }
+#else /* !ENABLED (JERRY_ES2015) */
+        lexer_next_token (context_p);
+
+        if (context_p->token.type != LEXER_RIGHT_PAREN)
+        {
+          while (true)
+          {
+            if (++call_arguments > CBC_MAXIMUM_BYTE_VALUE)
+            {
+              parser_raise_error (context_p, PARSER_ERR_ARGUMENT_LIMIT_REACHED);
+            }
+
+            parser_parse_expression (context_p, PARSE_EXPR_NO_COMMA);
+
+            if (context_p->token.type != LEXER_COMMA)
+            {
+              break;
+            }
+            lexer_next_token (context_p);
+          }
+
+          if (context_p->token.type != LEXER_RIGHT_PAREN)
+          {
+            parser_raise_error (context_p, PARSER_ERR_RIGHT_PAREN_EXPECTED);
           }
-#if ENABLED (JERRY_ES2015)
         }
 #endif /* ENABLED (JERRY_ES2015) */
 
diff --git a/tests/jerry/es2015/function-call.js b/tests/jerry/es2015/function-call.js
new file mode 100644
index 000000000..74a606817
--- /dev/null
+++ b/tests/jerry/es2015/function-call.js
@@ -0,0 +1,38 @@
+// Copyright JS Foundation and other contributors, http://js.foundation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+function check_syntax_error (code)
+{
+  try {
+    eval (code)
+    assert (false)
+  } catch (e) {
+    assert (e instanceof SyntaxError)
+  }
+}
+
+function f(...a)
+{
+  return a.length
+}
+
+check_syntax_error ("f(,)")
+check_syntax_error ("f(,1)")
+check_syntax_error ("f(1,,)")
+check_syntax_error ("f(1,,2)")
+
+assert(f(10) === 1)
+assert(f(10,) === 1)
+assert(f(10,11) === 2)
+assert(f(10,11,) === 2)