gn format: fix comments at end of blocks

tools/gn/parser_unittest.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <iostream>
 #include <sstream>
 
 #include "testing/gtest/include/gtest/gtest.h"
 #include "tools/gn/input_file.h"
 #include "tools/gn/parser.h"
@@ skipping 615 matching lines @@
     "BLOCK\n"
     " BINARY(=)\n"
     "  IDENTIFIER(defines)\n"
     "  LIST\n"
     "   LITERAL(\"WEE\")\n"
     "    +BEFORE_COMMENT(\"# Connected comment.\")\n"
     "   LITERAL(\"BLORPY\")\n";
   DoParserPrintTest(input, expected);
 }
 
+TEST(Parser, CommentsAtEndOfBlock) {
+  const char* input =
+    "if (is_win) {\n"
+    "  sources = [\"a.cc\"]\n"
+    "  # Some comment at end.\n"
+    "}\n";
+  const char* expected =
+    "BLOCK\n"
+    " CONDITION\n"
+    "  IDENTIFIER(is_win)\n"
+    "  BLOCK\n"
+    "   BINARY(=)\n"
+    "    IDENTIFIER(sources)\n"
+    "    LIST\n"
+    "     LITERAL(\"a.cc\")\n"
+    "   END(})\n"
+    "    +BEFORE_COMMENT(\"# Some comment at end.\")\n";
+  DoParserPrintTest(input, expected);
+}
+
+// TODO(scottmg): I could be convinced this is incorrect. It's not clear to me
+// which thing this comment is intended to be attached to.
+TEST(Parser, CommentsEndOfBlockSingleLine) {
+  const char* input =
+    "defines = [ # EOL defines.\n"
+    "]\n";
+  const char* expected =
+    "BLOCK\n"
+    " BINARY(=)\n"
+    "  IDENTIFIER(defines)\n"
+    "   +SUFFIX_COMMENT(\"# EOL defines.\")\n"
+    "  LIST\n";
+  DoParserPrintTest(input, expected);
+}
+
 TEST(Parser, HangingIf) {
   DoParserErrorTest("if", 1, 1);
 }
 
 TEST(Parser, NegatingList) {
   DoParserErrorTest("executable(\"wee\") { sources =- [ \"foo.cc\" ] }", 1, 30);
 }