Stop doing unnecessary UTF-8 to UTF-16 conversions in JSONWriter.

base/json/string_escape_unittest.cc

-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// 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 "base/json/string_escape.h"
+
+#include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
 
-namespace {
+TEST(JSONStringEscapeTest, EscapeUTF8) {
+  const struct {
+    const char* to_escape;
+    const char* escaped;
+  } cases[] = {
+    {"\b\001aZ\"\\wee", "\\b\\u0001aZ\\\"\\\\wee"},
+    {"a\b\f\n\r\t\v\1\\.\"z",
+        "a\\b\\f\\n\\r\\t\\u000B\\u0001\\\\.\\\"z"},
+    {"b\x0f\x7f\xf0\xff!",  // \xf0\xff is not a valid UTF-8 unit.
+        "b\\u000F\x7F\xEF\xBF\xBD\xEF\xBF\xBD!"},
+    {"c<>d", "c\\u003C>d"},
+  };
 
-const struct json_narrow_test_data {
-  const char* to_escape;
-  const char* escaped;
-} json_narrow_cases[] = {
-  {"\b\001aZ\"\\wee", "\\b\\u0001aZ\\\"\\\\wee"},
-  {"a\b\f\n\r\t\v\1\\.\"z",
-      "a\\b\\f\\n\\r\\t\\u000B\\u0001\\\\.\\\"z"},
-  {"b\x0f\x7f\xf0\xff!", "b\\u000F\\u007F\\u00F0\\u00FF!"},
-  {"c<>d", "c\\u003C\\u003Ed"},
-};
+  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(cases); ++i) {
+    const char* in_ptr = cases[i].to_escape;
+    std::string in_str = in_ptr;
 
-}  // namespace
+    std::string out;
+    EscapeJSONString(in_ptr, false, &out);
+    EXPECT_EQ(std::string(cases[i].escaped), out);
+    EXPECT_TRUE(IsStringUTF8(out));
 
-TEST(StringEscapeTest, JsonDoubleQuoteNarrow) {
-  for (size_t i = 0; i < arraysize(json_narrow_cases); ++i) {
-    const char* in_ptr = json_narrow_cases[i].to_escape;
-    std::string in_str = in_ptr;
-    std::string out;
-    JsonDoubleQuote(in_ptr, false, &out);
-    EXPECT_EQ(std::string(json_narrow_cases[i].escaped), out);
     out.erase();
-    JsonDoubleQuote(in_str, false, &out);
-    EXPECT_EQ(std::string(json_narrow_cases[i].escaped), out);
+    bool convert_ok = EscapeJSONString(in_str, false, &out);
+    EXPECT_EQ(std::string(cases[i].escaped), out);
+    EXPECT_TRUE(IsStringUTF8(out));
+
+    if (convert_ok) {
+      std::string fooout = GetQuotedJSONString(in_str);
+      EXPECT_EQ("\"" + std::string(cases[i].escaped) + "\"", fooout);
+      EXPECT_TRUE(IsStringUTF8(out));
+    }
   }
 
-  std::string in = json_narrow_cases[0].to_escape;
+  std::string in = cases[0].to_escape;
   std::string out;
-  JsonDoubleQuote(in, false, &out);
+  EscapeJSONString(in, false, &out);
+  EXPECT_TRUE(IsStringUTF8(out));
 
   // test quoting
   std::string out_quoted;
-  JsonDoubleQuote(in, true, &out_quoted);
+  EscapeJSONString(in, true, &out_quoted);
   EXPECT_EQ(out.length() + 2, out_quoted.length());
   EXPECT_EQ(out_quoted.find(out), 1U);
+  EXPECT_TRUE(IsStringUTF8(out_quoted));
 
   // now try with a NULL in the string
   std::string null_prepend = "test";
   null_prepend.push_back(0);
   in = null_prepend + in;
   std::string expected = "test\\u0000";
-  expected += json_narrow_cases[0].escaped;
+  expected += cases[0].escaped;
   out.clear();
-  JsonDoubleQuote(in, false, &out);
+  EscapeJSONString(in, false, &out);
   EXPECT_EQ(expected, out);
+  EXPECT_TRUE(IsStringUTF8(out));
 }
 
-namespace {
+TEST(JSONStringEscapeTest, EscapeUTF16) {
+  const struct {
+    const wchar_t* to_escape;
+    const char* escaped;
+  } cases[] = {
+    {L"b\uffb1\u00ff", "b\xEF\xBE\xB1\xC3\xBF"},
+    {L"\b\001aZ\"\\wee", "\\b\\u0001aZ\\\"\\\\wee"},
+    {L"a\b\f\n\r\t\v\1\\.\"z",
+        "a\\b\\f\\n\\r\\t\\u000B\\u0001\\\\.\\\"z"},
+    {L"b\x0f\x7f\xf0\xff!", "b\\u000F\x7F\xC3\xB0\xC3\xBF!"},
+    {L"c<>d", "c\\u003C>d"},
+  };
 
-const struct json_wide_test_data {
-  const wchar_t* to_escape;
-  const char* escaped;
-} json_wide_cases[] = {
-  {L"b\uffb1\u00ff", "b\\uFFB1\\u00FF"},
-  {L"\b\001aZ\"\\wee", "\\b\\u0001aZ\\\"\\\\wee"},
-  {L"a\b\f\n\r\t\v\1\\.\"z",
-      "a\\b\\f\\n\\r\\t\\u000B\\u0001\\\\.\\\"z"},
-  {L"b\x0f\x7f\xf0\xff!", "b\\u000F\\u007F\\u00F0\\u00FF!"},
-  {L"c<>d", "c\\u003C\\u003Ed"},
-};
+  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(cases); ++i) {
+    string16 in = WideToUTF16(cases[i].to_escape);
 
-}  // namespace
+    std::string out;
+    EscapeJSONString(in, false, &out);
+    EXPECT_EQ(std::string(cases[i].escaped), out);
+    EXPECT_TRUE(IsStringUTF8(out));
 
-TEST(StringEscapeTest, JsonDoubleQuoteWide) {
-  for (size_t i = 0; i < arraysize(json_wide_cases); ++i) {
-    std::string out;
-    string16 in = WideToUTF16(json_wide_cases[i].to_escape);
-    JsonDoubleQuote(in, false, &out);
-    EXPECT_EQ(std::string(json_wide_cases[i].escaped), out);
+    out = GetQuotedJSONString(in);
+    EXPECT_EQ("\"" + std::string(cases[i].escaped) + "\"", out);
+    EXPECT_TRUE(IsStringUTF8(out));
   }
 
-  string16 in = WideToUTF16(json_wide_cases[0].to_escape);
+  string16 in = WideToUTF16(cases[0].to_escape);
   std::string out;
-  JsonDoubleQuote(in, false, &out);
+  EscapeJSONString(in, false, &out);
+  EXPECT_TRUE(IsStringUTF8(out));
 
   // test quoting
   std::string out_quoted;
-  JsonDoubleQuote(in, true, &out_quoted);
+  EscapeJSONString(in, true, &out_quoted);
   EXPECT_EQ(out.length() + 2, out_quoted.length());
   EXPECT_EQ(out_quoted.find(out), 1U);
+  EXPECT_TRUE(IsStringUTF8(out));
 
   // now try with a NULL in the string
   string16 null_prepend = WideToUTF16(L"test");
   null_prepend.push_back(0);
   in = null_prepend + in;
   std::string expected = "test\\u0000";
-  expected += json_wide_cases[0].escaped;
+  expected += cases[0].escaped;
   out.clear();
-  JsonDoubleQuote(in, false, &out);
+  EscapeJSONString(in, false, &out);
   EXPECT_EQ(expected, out);
+  EXPECT_TRUE(IsStringUTF8(out));
+}
+
+TEST(JSONStringEscapeTest, EscapeUTF16OutsideBMP) {
+  {
+    // {a, U+10300, !}, SMP.
+    string16 test;
+    test.push_back('a');
+    test.push_back(0xD800);
+    test.push_back(0xDF00);
+    test.push_back('!');
+    std::string actual;
+    EXPECT_TRUE(EscapeJSONString(test, false, &actual));
+    EXPECT_EQ("a\xF0\x90\x8C\x80!", actual);
+  }
+  {
+    // {U+20021, U+2002B}, SIP.
+    string16 test;
+    test.push_back(0xD840);
+    test.push_back(0xDC21);
+    test.push_back(0xD840);
+    test.push_back(0xDC2B);
+    std::string actual;
+    EXPECT_TRUE(EscapeJSONString(test, false, &actual));
+    EXPECT_EQ("\xF0\xA0\x80\xA1\xF0\xA0\x80\xAB", actual);
+  }
+  {
+    // {?, U+D800, @}, lone surrogate.
+    string16 test;
+    test.push_back('?');
+    test.push_back(0xD800);
+    test.push_back('@');
+    std::string actual;
+    EXPECT_FALSE(EscapeJSONString(test, false, &actual));
+    EXPECT_EQ("?\xEF\xBF\xBD@", actual);
+  }
+}
+
+TEST(JSONStringEscapeTest, EscapeBytes) {
+  const struct {
+    const char* to_escape;
+    const char* escaped;
+  } cases[] = {
+    {"b\x0f\x7f\xf0\xff!", "b\\u000F\\u007F\\u00F0\\u00FF!"},
+    {"\xe5\xc4\x4f\x05\xb6\xfd\0", "\\u00E5\\u00C4O\\u0005\\u00B6\\u00FD"},
+  };
+
+  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(cases); ++i) {
+    std::string in = std::string(cases[i].to_escape);
+    EXPECT_FALSE(IsStringUTF8(in));
+
+    EXPECT_EQ(std::string(cases[i].escaped),
+        EscapeBytesAsInvalidJSONString(in, false));
+    EXPECT_EQ("\"" + std::string(cases[i].escaped) + "\"",
+        EscapeBytesAsInvalidJSONString(in, true));
+  }
+
+  const char kEmbedNull[] = { '\xab', '\x39', '\0', '\x9f', '\xab' };
+  std::string in(kEmbedNull, ARRAYSIZE_UNSAFE(kEmbedNull));
+  EXPECT_FALSE(IsStringUTF8(in));
+  EXPECT_EQ(std::string("\\u00AB9\\u0000\\u009F\\u00AB"),
+            EscapeBytesAsInvalidJSONString(in, false));
 }
 
 }  // namespace base