JSONStringValueSerializer takes a StringPiece instead of std::string&.

base/json/json_value_serializer_unittest.cc

 // Copyright (c) 2012 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 <string>
 
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/json/json_file_value_serializer.h"
 #include "base/json/json_reader.h"
 #include "base/json/json_string_value_serializer.h"
 #include "base/json/json_writer.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/path_service.h"
+#include "base/strings/string_piece.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
 
 namespace {
 
 // Some proper JSON to test with:
@@ skipping 10 matching lines @@
 
 // Some proper JSON with trailing commas:
 const char kProperJSONWithCommas[] =
     "{\n"
     "\t\"some_int\": 42,\n"
     "\t\"some_String\": \"1337\",\n"
     "\t\"the_list\": [\"val1\", \"val2\", ],\n"
     "\t\"compound\": { \"a\": 1, \"b\": 2, },\n"
     "}\n";
 
+// kProperJSON with a few misc characters at the begin and end.
+const char kProperJSONPadded[] =
+    ")]}'\n"
+    "{\n"
+    "   \"compound\": {\n"
+    "      \"a\": 1,\n"
+    "      \"b\": 2\n"
+    "   },\n"
+    "   \"some_String\": \"1337\",\n"
+    "   \"some_int\": 42,\n"
+    "   \"the_list\": [ \"val1\", \"val2\" ]\n"
+    "}\n"
+    "?!ab\n";
+
 const char kWinLineEnds[] = "\r\n";
 const char kLinuxLineEnds[] = "\n";
 
 // Verifies the generated JSON against the expected output.
 void CheckJSONIsStillTheSame(Value& value) {
   // Serialize back the output.
   std::string serialized_json;
   JSONStringValueSerializer str_serializer(&serialized_json);
   str_serializer.set_pretty_print(true);
   ASSERT_TRUE(str_serializer.Serialize(value));
@@ skipping 12 matching lines @@
   Value* elt = NULL;
   ASSERT_TRUE(list->Get(0, &elt));
   int value = 0;
   ASSERT_TRUE(elt && elt->GetAsInteger(&value));
   ASSERT_EQ(1, value);
 }
 
 // Test proper JSON [de]serialization from string is working.
 TEST(JSONValueSerializerTest, ReadProperJSONFromString) {
   // Try to deserialize it through the serializer.
+  JSONStringValueSerializer str_deserializer(kProperJSON);
+
+  int error_code = 0;
+  std::string error_message;
+  scoped_ptr<Value> value(
+      str_deserializer.Deserialize(&error_code, &error_message));
+  ASSERT_TRUE(value.get());
+  ASSERT_EQ(0, error_code);
+  ASSERT_TRUE(error_message.empty());
+  // Verify if the same JSON is still there.
+  CheckJSONIsStillTheSame(*value);
+}
+
+// Test proper JSON deserialization from a string pointer is working.
+TEST(JSONValueSerializerTest, ReadProperJSONFromStringPointer) {
+  // Try to deserialize a string pointer through the serializer. (This exercises
+  // a separate code path to passing a StringPiece.)
   std::string proper_json(kProperJSON);
+  JSONStringValueSerializer str_deserializer(&proper_json);
+
+  int error_code = 0;
+  std::string error_message;
+  scoped_ptr<Value> value(
+      str_deserializer.Deserialize(&error_code, &error_message));
+  ASSERT_TRUE(value.get());
+  ASSERT_EQ(0, error_code);
+  ASSERT_TRUE(error_message.empty());
+  // Verify if the same JSON is still there.
+  CheckJSONIsStillTheSame(*value);
+}
+
+// Test proper JSON deserialization from a StringPiece substring.
+TEST(JSONValueSerializerTest, ReadProperJSONFromStringPiece) {
+  // Create a StringPiece for the substring of kProperJSONPadded that matches
+  // kProperJSON.
+  base::StringPiece proper_json(kProperJSONPadded);
+  proper_json = proper_json.substr(5, proper_json.length() - 10);
   JSONStringValueSerializer str_deserializer(proper_json);
 
   int error_code = 0;
   std::string error_message;
   scoped_ptr<Value> value(
       str_deserializer.Deserialize(&error_code, &error_message));
   ASSERT_TRUE(value.get());
   ASSERT_EQ(0, error_code);
   ASSERT_TRUE(error_message.empty());
   // Verify if the same JSON is still there.
   CheckJSONIsStillTheSame(*value);
 }
 
 // Test that trialing commas are only properly deserialized from string when
 // the proper flag for that is set.
 TEST(JSONValueSerializerTest, ReadJSONWithTrailingCommasFromString) {
   // Try to deserialize it through the serializer.
-  std::string proper_json(kProperJSONWithCommas);
-  JSONStringValueSerializer str_deserializer(proper_json);
+  JSONStringValueSerializer str_deserializer(kProperJSONWithCommas);
 
   int error_code = 0;
   std::string error_message;
   scoped_ptr<Value> value(
       str_deserializer.Deserialize(&error_code, &error_message));
   ASSERT_FALSE(value.get());
   ASSERT_NE(0, error_code);
   ASSERT_FALSE(error_message.empty());
   // Now the flag is set and it must pass.
   str_deserializer.set_allow_trailing_comma(true);
@@ skipping 51 matching lines @@
   // Now the flag is set and it must pass.
   file_deserializer.set_allow_trailing_comma(true);
   value.reset(file_deserializer.Deserialize(&error_code, &error_message));
   ASSERT_TRUE(value.get());
   ASSERT_EQ(JSONReader::JSON_TRAILING_COMMA, error_code);
   // Verify if the same JSON is still there.
   CheckJSONIsStillTheSame(*value);
 }
 
 TEST(JSONValueSerializerTest, Roundtrip) {
-  const std::string original_serialization =
+  static const char kOriginalSerialization[] =
     "{\"bool\":true,\"double\":3.14,\"int\":42,\"list\":[1,2],\"null\":null}";
-  JSONStringValueSerializer serializer(original_serialization);
+  JSONStringValueSerializer serializer(kOriginalSerialization);
   scoped_ptr<Value> root(serializer.Deserialize(NULL, NULL));
   ASSERT_TRUE(root.get());
   ASSERT_TRUE(root->IsType(Value::TYPE_DICTIONARY));
 
   DictionaryValue* root_dict = static_cast<DictionaryValue*>(root.get());
 
   Value* null_value = NULL;
   ASSERT_TRUE(root_dict->Get("null", &null_value));
   ASSERT_TRUE(null_value);
   ASSERT_TRUE(null_value->IsType(Value::TYPE_NULL));
@@ skipping 10 matching lines @@
   ASSERT_TRUE(root_dict->GetDouble("double", &double_value));
   ASSERT_DOUBLE_EQ(3.14, double_value);
 
   // We shouldn't be able to write using this serializer, since it was
   // initialized with a const string.
   ASSERT_FALSE(serializer.Serialize(*root_dict));
 
   std::string test_serialization;
   JSONStringValueSerializer mutable_serializer(&test_serialization);
   ASSERT_TRUE(mutable_serializer.Serialize(*root_dict));
-  ASSERT_EQ(original_serialization, test_serialization);
+  ASSERT_EQ(kOriginalSerialization, test_serialization);
 
   mutable_serializer.set_pretty_print(true);
   ASSERT_TRUE(mutable_serializer.Serialize(*root_dict));
   // JSON output uses a different newline style on Windows than on other
   // platforms.
 #if defined(OS_WIN)
 #define JSON_NEWLINE "\r\n"
 #else
 #define JSON_NEWLINE "\n"
 #endif
@@ skipping 54 matching lines @@
   ASSERT_TRUE(serializer.Serialize(valueRoot));
   ASSERT_EQ(expected_output, output_js);
 }
 
 TEST(JSONValueSerializerTest, UnicodeStrings) {
   // unicode string json -> escaped ascii text
   DictionaryValue root;
   string16 test(WideToUTF16(L"\x7F51\x9875"));
   root.SetString("web", test);
 
-  std::string expected = "{\"web\":\"\xE7\xBD\x91\xE9\xA1\xB5\"}";
+  static const char kExpected[] = "{\"web\":\"\xE7\xBD\x91\xE9\xA1\xB5\"}";
 
   std::string actual;
   JSONStringValueSerializer serializer(&actual);
   ASSERT_TRUE(serializer.Serialize(root));
-  ASSERT_EQ(expected, actual);
+  ASSERT_EQ(kExpected, actual);
 
   // escaped ascii text -> json
-  JSONStringValueSerializer deserializer(expected);
+  JSONStringValueSerializer deserializer(kExpected);
   scoped_ptr<Value> deserial_root(deserializer.Deserialize(NULL, NULL));
   ASSERT_TRUE(deserial_root.get());
   DictionaryValue* dict_root =
       static_cast<DictionaryValue*>(deserial_root.get());
   string16 web_value;
   ASSERT_TRUE(dict_root->GetString("web", &web_value));
   ASSERT_EQ(test, web_value);
 }
 
 TEST(JSONValueSerializerTest, HexStrings) {
   // hex string json -> escaped ascii text
   DictionaryValue root;
   string16 test(WideToUTF16(L"\x01\x02"));
   root.SetString("test", test);
 
-  std::string expected = "{\"test\":\"\\u0001\\u0002\"}";
+  static const char kExpected[] = "{\"test\":\"\\u0001\\u0002\"}";
 
   std::string actual;
   JSONStringValueSerializer serializer(&actual);
   ASSERT_TRUE(serializer.Serialize(root));
-  ASSERT_EQ(expected, actual);
+  ASSERT_EQ(kExpected, actual);
 
   // escaped ascii text -> json
-  JSONStringValueSerializer deserializer(expected);
+  JSONStringValueSerializer deserializer(kExpected);
   scoped_ptr<Value> deserial_root(deserializer.Deserialize(NULL, NULL));
   ASSERT_TRUE(deserial_root.get());
   DictionaryValue* dict_root =
       static_cast<DictionaryValue*>(deserial_root.get());
   string16 test_value;
   ASSERT_TRUE(dict_root->GetString("test", &test_value));
   ASSERT_EQ(test, test_value);
 
   // Test converting escaped regular chars
-  std::string escaped_chars = "{\"test\":\"\\u0067\\u006f\"}";
-  JSONStringValueSerializer deserializer2(escaped_chars);
+  static const char kEscapedChars[] = "{\"test\":\"\\u0067\\u006f\"}";
+  JSONStringValueSerializer deserializer2(kEscapedChars);
   deserial_root.reset(deserializer2.Deserialize(NULL, NULL));
   ASSERT_TRUE(deserial_root.get());
   dict_root = static_cast<DictionaryValue*>(deserial_root.get());
   ASSERT_TRUE(dict_root->GetString("test", &test_value));
   ASSERT_EQ(ASCIIToUTF16("go"), test_value);
 }
 
 TEST(JSONValueSerializerTest, AllowTrailingComma) {
   scoped_ptr<Value> root;
   scoped_ptr<Value> root_expected;
-  std::string test_with_commas("{\"key\": [true,],}");
-  std::string test_no_commas("{\"key\": [true]}");
+  static const char kTestWithCommas[] = "{\"key\": [true,],}";
+  static const char kTestNoCommas[] = "{\"key\": [true]}";
 
-  JSONStringValueSerializer serializer(test_with_commas);
+  JSONStringValueSerializer serializer(kTestWithCommas);
   serializer.set_allow_trailing_comma(true);
-  JSONStringValueSerializer serializer_expected(test_no_commas);
+  JSONStringValueSerializer serializer_expected(kTestNoCommas);
   root.reset(serializer.Deserialize(NULL, NULL));
   ASSERT_TRUE(root.get());
   root_expected.reset(serializer_expected.Deserialize(NULL, NULL));
   ASSERT_TRUE(root_expected.get());
   ASSERT_TRUE(root->Equals(root_expected.get()));
 }
 
 TEST(JSONValueSerializerTest, JSONReaderComments) {
   ValidateJsonList("[ // 2, 3, ignore me ] \n1 ]");
   ValidateJsonList("[ /* 2, \n3, ignore me ]*/ \n1 ]");
@@ skipping 114 matching lines @@
   ASSERT_TRUE(PathExists(source_file_path));
   JSONFileValueSerializer serializer(source_file_path);
   scoped_ptr<Value> root;
   root.reset(serializer.Deserialize(NULL, NULL));
   ASSERT_TRUE(root.get());
 }
 
 }  // namespace
 
 }  // namespace base