url/url_util_unittest.cc - chromium/src - Git at Google

 // Copyright 2013 The Chromium Authors
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #include "url/url_util.h"

 #include <stddef.h>

 #include "base/strings/string_piece.h"
 #include "build/build_config.h"
 #include "testing/gtest/include/gtest/gtest-message.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/abseil-cpp/absl/types/optional.h"
 #include "url/third_party/mozilla/url_parse.h"
 #include "url/url_canon.h"
 #include "url/url_canon_stdstring.h"
 #include "url/url_test_utils.h"

 namespace url {

 class URLUtilTest : public testing::Test {
  public:
   URLUtilTest() = default;

   URLUtilTest(const URLUtilTest&) = delete;
   URLUtilTest& operator=(const URLUtilTest&) = delete;

   ~URLUtilTest() override = default;

  private:
   ScopedSchemeRegistryForTests scoped_registry_;
 };

 TEST_F(URLUtilTest, FindAndCompareScheme) {
   Component found_scheme;

   // Simple case where the scheme is found and matches.
   const char kStr1[] = "http://www.com/";
   EXPECT_TRUE(FindAndCompareScheme(
       kStr1, static_cast<int>(strlen(kStr1)), "http", NULL));
   EXPECT_TRUE(FindAndCompareScheme(
       kStr1, static_cast<int>(strlen(kStr1)), "http", &found_scheme));
   EXPECT_TRUE(found_scheme == Component(0, 4));

   // A case where the scheme is found and doesn't match.
   EXPECT_FALSE(FindAndCompareScheme(
       kStr1, static_cast<int>(strlen(kStr1)), "https", &found_scheme));
   EXPECT_TRUE(found_scheme == Component(0, 4));

   // A case where there is no scheme.
   const char kStr2[] = "httpfoobar";
   EXPECT_FALSE(FindAndCompareScheme(
       kStr2, static_cast<int>(strlen(kStr2)), "http", &found_scheme));
   EXPECT_TRUE(found_scheme == Component());

   // When there is an empty scheme, it should match the empty scheme.
   const char kStr3[] = ":foo.com/";
   EXPECT_TRUE(FindAndCompareScheme(
       kStr3, static_cast<int>(strlen(kStr3)), "", &found_scheme));
   EXPECT_TRUE(found_scheme == Component(0, 0));

   // But when there is no scheme, it should fail.
   EXPECT_FALSE(FindAndCompareScheme("", 0, "", &found_scheme));
   EXPECT_TRUE(found_scheme == Component());

   // When there is a whitespace char in scheme, it should canonicalize the URL
   // before comparison.
   const char whtspc_str[] = " \r\n\tjav\ra\nscri\tpt:alert(1)";
   EXPECT_TRUE(FindAndCompareScheme(whtspc_str,
                                    static_cast<int>(strlen(whtspc_str)),
                                    "javascript", &found_scheme));
   EXPECT_TRUE(found_scheme == Component(1, 10));

   // Control characters should be stripped out on the ends, and kept in the
   // middle.
   const char ctrl_str[] = "\02jav\02scr\03ipt:alert(1)";
   EXPECT_FALSE(FindAndCompareScheme(ctrl_str,
                                     static_cast<int>(strlen(ctrl_str)),
                                     "javascript", &found_scheme));
   EXPECT_TRUE(found_scheme == Component(1, 11));
 }

 TEST_F(URLUtilTest, IsStandard) {
   const char kHTTPScheme[] = "http";
   EXPECT_TRUE(IsStandard(kHTTPScheme, Component(0, strlen(kHTTPScheme))));

   const char kFooScheme[] = "foo";
   EXPECT_FALSE(IsStandard(kFooScheme, Component(0, strlen(kFooScheme))));
 }

 TEST_F(URLUtilTest, IsReferrerScheme) {
   const char kHTTPScheme[] = "http";
   EXPECT_TRUE(IsReferrerScheme(kHTTPScheme, Component(0, strlen(kHTTPScheme))));

   const char kFooScheme[] = "foo";
   EXPECT_FALSE(IsReferrerScheme(kFooScheme, Component(0, strlen(kFooScheme))));
 }

 TEST_F(URLUtilTest, AddReferrerScheme) {
   static const char kFooScheme[] = "foo";
   EXPECT_FALSE(IsReferrerScheme(kFooScheme, Component(0, strlen(kFooScheme))));

   url::ScopedSchemeRegistryForTests scoped_registry;
   AddReferrerScheme(kFooScheme, url::SCHEME_WITH_HOST);
   EXPECT_TRUE(IsReferrerScheme(kFooScheme, Component(0, strlen(kFooScheme))));
 }

 TEST_F(URLUtilTest, ShutdownCleansUpSchemes) {
   static const char kFooScheme[] = "foo";
   EXPECT_FALSE(IsReferrerScheme(kFooScheme, Component(0, strlen(kFooScheme))));

   {
     url::ScopedSchemeRegistryForTests scoped_registry;
     AddReferrerScheme(kFooScheme, url::SCHEME_WITH_HOST);
     EXPECT_TRUE(IsReferrerScheme(kFooScheme, Component(0, strlen(kFooScheme))));
   }

   EXPECT_FALSE(IsReferrerScheme(kFooScheme, Component(0, strlen(kFooScheme))));
 }

 TEST_F(URLUtilTest, GetStandardSchemeType) {
   url::SchemeType scheme_type;

   const char kHTTPScheme[] = "http";
   scheme_type = url::SCHEME_WITHOUT_AUTHORITY;
   EXPECT_TRUE(GetStandardSchemeType(kHTTPScheme,
                                     Component(0, strlen(kHTTPScheme)),
                                     &scheme_type));
   EXPECT_EQ(url::SCHEME_WITH_HOST_PORT_AND_USER_INFORMATION, scheme_type);

   const char kFilesystemScheme[] = "filesystem";
   scheme_type = url::SCHEME_WITH_HOST_PORT_AND_USER_INFORMATION;
   EXPECT_TRUE(GetStandardSchemeType(kFilesystemScheme,
                                     Component(0, strlen(kFilesystemScheme)),
                                     &scheme_type));
   EXPECT_EQ(url::SCHEME_WITHOUT_AUTHORITY, scheme_type);

   const char kFooScheme[] = "foo";
   scheme_type = url::SCHEME_WITH_HOST_PORT_AND_USER_INFORMATION;
   EXPECT_FALSE(GetStandardSchemeType(kFooScheme,
                                      Component(0, strlen(kFooScheme)),
                                      &scheme_type));
 }

 TEST_F(URLUtilTest, GetStandardSchemes) {
   std::vector<std::string> expected = {
       kHttpsScheme,      kHttpScheme,          kFileScheme,
       kFtpScheme,        kWssScheme,           kWsScheme,
       kFileSystemScheme, kQuicTransportScheme, "foo",
   };
   AddStandardScheme("foo", url::SCHEME_WITHOUT_AUTHORITY);
   EXPECT_EQ(expected, GetStandardSchemes());
 }

 TEST_F(URLUtilTest, ReplaceComponents) {
   Parsed parsed;
   RawCanonOutputT<char> output;
   Parsed new_parsed;

   // Check that the following calls do not cause crash
   Replacements<char> replacements;
   replacements.SetRef("test", Component(0, 4));
   ReplaceComponents(NULL, 0, parsed, replacements, NULL, &output, &new_parsed);
   ReplaceComponents("", 0, parsed, replacements, NULL, &output, &new_parsed);
   replacements.ClearRef();
   replacements.SetHost("test", Component(0, 4));
   ReplaceComponents(NULL, 0, parsed, replacements, NULL, &output, &new_parsed);
   ReplaceComponents("", 0, parsed, replacements, NULL, &output, &new_parsed);

   replacements.ClearHost();
   ReplaceComponents(NULL, 0, parsed, replacements, NULL, &output, &new_parsed);
   ReplaceComponents("", 0, parsed, replacements, NULL, &output, &new_parsed);
   ReplaceComponents(NULL, 0, parsed, replacements, NULL, &output, &new_parsed);
   ReplaceComponents("", 0, parsed, replacements, NULL, &output, &new_parsed);
 }

 static std::string CheckReplaceScheme(const char* base_url,
                                       const char* scheme) {
   // Make sure the input is canonicalized.
   RawCanonOutput<32> original;
   Parsed original_parsed;
   Canonicalize(base_url, strlen(base_url), true, NULL, &original,
                &original_parsed);

   Replacements<char> replacements;
   replacements.SetScheme(scheme, Component(0, strlen(scheme)));

   std::string output_string;
   StdStringCanonOutput output(&output_string);
   Parsed output_parsed;
   ReplaceComponents(original.data(), original.length(), original_parsed,
                     replacements, NULL, &output, &output_parsed);

   output.Complete();
   return output_string;
 }

 TEST_F(URLUtilTest, ReplaceScheme) {
   EXPECT_EQ("https://google.com/",
             CheckReplaceScheme("http://google.com/", "https"));
   EXPECT_EQ("file://google.com/",
             CheckReplaceScheme("http://google.com/", "file"));
   EXPECT_EQ("http://home/Build",
             CheckReplaceScheme("file:///Home/Build", "http"));
   EXPECT_EQ("javascript:foo",
             CheckReplaceScheme("about:foo", "javascript"));
   EXPECT_EQ("://google.com/",
             CheckReplaceScheme("http://google.com/", ""));
   EXPECT_EQ("http://google.com/",
             CheckReplaceScheme("about:google.com", "http"));
   EXPECT_EQ("http:", CheckReplaceScheme("", "http"));

 #ifdef WIN32
   // Magic Windows drive letter behavior when converting to a file URL.
   EXPECT_EQ("file:///E:/foo/",
             CheckReplaceScheme("http://localhost/e:foo/", "file"));
 #endif

   // This will probably change to "about://google.com/" when we fix
   // http://crbug.com/160 which should also be an acceptable result.
   EXPECT_EQ("about://google.com/",
             CheckReplaceScheme("http://google.com/", "about"));

   EXPECT_EQ("http://example.com/%20hello%20#%20world",
             CheckReplaceScheme("myscheme:example.com/ hello # world ", "http"));
 }

 TEST_F(URLUtilTest, DecodeURLEscapeSequences) {
   struct DecodeCase {
     const char* input;
     const char* output;
   } decode_cases[] = {
       {"hello, world", "hello, world"},
       {"%01%02%03%04%05%06%07%08%09%0a%0B%0C%0D%0e%0f/",
        "\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0B\x0C\x0D\x0e\x0f/"},
       {"%10%11%12%13%14%15%16%17%18%19%1a%1B%1C%1D%1e%1f/",
        "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1B\x1C\x1D\x1e\x1f/"},
       {"%20%21%22%23%24%25%26%27%28%29%2a%2B%2C%2D%2e%2f/",
        " !\"#$%&'()*+,-.//"},
       {"%30%31%32%33%34%35%36%37%38%39%3a%3B%3C%3D%3e%3f/",
        "0123456789:;<=>?/"},
       {"%40%41%42%43%44%45%46%47%48%49%4a%4B%4C%4D%4e%4f/",
        "@ABCDEFGHIJKLMNO/"},
       {"%50%51%52%53%54%55%56%57%58%59%5a%5B%5C%5D%5e%5f/",
        "PQRSTUVWXYZ[\\]^_/"},
       {"%60%61%62%63%64%65%66%67%68%69%6a%6B%6C%6D%6e%6f/",
        "`abcdefghijklmno/"},
       {"%70%71%72%73%74%75%76%77%78%79%7a%7B%7C%7D%7e%7f/",
        "pqrstuvwxyz{|}~\x7f/"},
       {"%e4%bd%a0%e5%a5%bd", "\xe4\xbd\xa0\xe5\xa5\xbd"},
   };

   for (size_t i = 0; i < std::size(decode_cases); i++) {
     const char* input = decode_cases[i].input;
     RawCanonOutputT<char16_t> output;
     DecodeURLEscapeSequences(input, strlen(input),
                              DecodeURLMode::kUTF8OrIsomorphic, &output);
     EXPECT_EQ(decode_cases[i].output, base::UTF16ToUTF8(std::u16string(
                                           output.data(), output.length())));

     RawCanonOutputT<char16_t> output_utf8;
     DecodeURLEscapeSequences(input, strlen(input), DecodeURLMode::kUTF8,
                              &output_utf8);
     EXPECT_EQ(decode_cases[i].output,
               base::UTF16ToUTF8(
                   std::u16string(output_utf8.data(), output_utf8.length())));
   }

   // Our decode should decode %00
   const char zero_input[] = "%00";
   RawCanonOutputT<char16_t> zero_output;
   DecodeURLEscapeSequences(zero_input, strlen(zero_input), DecodeURLMode::kUTF8,
                            &zero_output);
   EXPECT_NE("%00", base::UTF16ToUTF8(std::u16string(zero_output.data(),
                                                     zero_output.length())));

   // Test the error behavior for invalid UTF-8.
   struct Utf8DecodeCase {
     const char* input;
     std::vector<char16_t> expected_iso;
     std::vector<char16_t> expected_utf8;
   } utf8_decode_cases[] = {
       // %e5%a5%bd is a valid UTF-8 sequence. U+597D
       {"%e4%a0%e5%a5%bd",
        {0x00e4, 0x00a0, 0x00e5, 0x00a5, 0x00bd, 0},
        {0xfffd, 0x597d, 0}},
       {"%e5%a5%bd%e4%a0",
        {0x00e5, 0x00a5, 0x00bd, 0x00e4, 0x00a0, 0},
        {0x597d, 0xfffd, 0}},
       {"%e4%a0%e5%bd",
        {0x00e4, 0x00a0, 0x00e5, 0x00bd, 0},
        {0xfffd, 0xfffd, 0}},
   };

   for (const auto& test : utf8_decode_cases) {
     const char* input = test.input;
     RawCanonOutputT<char16_t> output_iso;
     DecodeURLEscapeSequences(input, strlen(input),
                              DecodeURLMode::kUTF8OrIsomorphic, &output_iso);
     EXPECT_EQ(std::u16string(test.expected_iso.data()),
               std::u16string(output_iso.data(), output_iso.length()));

     RawCanonOutputT<char16_t> output_utf8;
     DecodeURLEscapeSequences(input, strlen(input), DecodeURLMode::kUTF8,
                              &output_utf8);
     EXPECT_EQ(std::u16string(test.expected_utf8.data()),
               std::u16string(output_utf8.data(), output_utf8.length()));
   }
 }

 TEST_F(URLUtilTest, TestEncodeURIComponent) {
   struct EncodeCase {
     const char* input;
     const char* output;
   } encode_cases[] = {
     {"hello, world", "hello%2C%20world"},
     {"\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0A\x0B\x0C\x0D\x0E\x0F",
      "%01%02%03%04%05%06%07%08%09%0A%0B%0C%0D%0E%0F"},
     {"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1A\x1B\x1C\x1D\x1E\x1F",
      "%10%11%12%13%14%15%16%17%18%19%1A%1B%1C%1D%1E%1F"},
     {" !\"#$%&'()*+,-./",
      "%20!%22%23%24%25%26%27()*%2B%2C-.%2F"},
     {"0123456789:;<=>?",
      "0123456789%3A%3B%3C%3D%3E%3F"},
     {"@ABCDEFGHIJKLMNO",
      "%40ABCDEFGHIJKLMNO"},
     {"PQRSTUVWXYZ[\\]^_",
      "PQRSTUVWXYZ%5B%5C%5D%5E_"},
     {"`abcdefghijklmno",
      "%60abcdefghijklmno"},
     {"pqrstuvwxyz{|}~\x7f",
      "pqrstuvwxyz%7B%7C%7D~%7F"},
   };

   for (size_t i = 0; i < std::size(encode_cases); i++) {
     const char* input = encode_cases[i].input;
     RawCanonOutputT<char> buffer;
     EncodeURIComponent(input, strlen(input), &buffer);
     std::string output(buffer.data(), buffer.length());
     EXPECT_EQ(encode_cases[i].output, output);
   }
 }

 TEST_F(URLUtilTest, TestResolveRelativeWithNonStandardBase) {
   // This tests non-standard (in the sense that IsStandard() == false)
   // hierarchical schemes.
   struct ResolveRelativeCase {
     const char* base;
     const char* rel;
     bool is_valid;
     const char* out;
   } resolve_non_standard_cases[] = {
       // Resolving a relative path against a non-hierarchical URL should fail.
       {"scheme:opaque_data", "/path", false, ""},
       // Resolving a relative path against a non-standard authority-based base
       // URL doesn't alter the authority section.
       {"scheme://Authority/", "../path", true, "scheme://Authority/path"},
       // A non-standard hierarchical base is resolved with path URL
       // canonicalization rules.
       {"data:/Blah:Blah/", "file.html", true, "data:/Blah:Blah/file.html"},
       {"data:/Path/../part/part2", "file.html", true,
        "data:/Path/../part/file.html"},
       {"data://text/html,payload", "//user:pass@host:33////payload22", true,
        "data://user:pass@host:33////payload22"},
       // Path URL canonicalization rules also apply to non-standard authority-
       // based URLs.
       {"custom://Authority/", "file.html", true,
        "custom://Authority/file.html"},
       {"custom://Authority/", "other://Auth/", true, "other://Auth/"},
       {"custom://Authority/", "../../file.html", true,
        "custom://Authority/file.html"},
       {"custom://Authority/path/", "file.html", true,
        "custom://Authority/path/file.html"},
       {"custom://Authority:NoCanon/path/", "file.html", true,
        "custom://Authority:NoCanon/path/file.html"},
       // It's still possible to get an invalid path URL.
       {"custom://Invalid:!#Auth/", "file.html", false, ""},
       // A path with an authority section gets canonicalized under standard URL
       // rules, even though the base was non-standard.
       {"content://content.Provider/", "//other.Provider", true,
        "content://other.provider/"},

       // Resolving an absolute URL doesn't cause canonicalization of the
       // result.
       {"about:blank", "custom://Authority", true, "custom://Authority"},
       // Fragment URLs can be resolved against a non-standard base.
       {"scheme://Authority/path", "#fragment", true,
        "scheme://Authority/path#fragment"},
       {"scheme://Authority/", "#fragment", true,
        "scheme://Authority/#fragment"},
       // Resolving should fail if the base URL is authority-based but is
       // missing a path component (the '/' at the end).
       {"scheme://Authority", "path", false, ""},
       // Test resolving a fragment (only) against any kind of base-URL.
       {"about:blank", "#id42", true, "about:blank#id42"},
       {"about:blank", " #id42", true, "about:blank#id42"},
       {"about:blank#oldfrag", "#newfrag", true, "about:blank#newfrag"},
       // A surprising side effect of allowing fragments to resolve against
       // any URL scheme is we might break javascript: URLs by doing so...
       {"javascript:alert('foo#bar')", "#badfrag", true,
        "javascript:alert('foo#badfrag"},
       // In this case, the backslashes will not be canonicalized because it's a
       // non-standard URL, but they will be treated as a path separators,
       // giving the base URL here a path of "\".
       //
       // The result here is somewhat arbitrary. One could argue it should be
       // either "aaa://a\" or "aaa://a/" since the path is being replaced with
       // the "current directory". But in the context of resolving on data URLs,
       // adding the requested dot doesn't seem wrong either.
       {"aaa://a\\", "aaa:.", true, "aaa://a\\."}};

   for (size_t i = 0; i < std::size(resolve_non_standard_cases); i++) {
     const ResolveRelativeCase& test_data = resolve_non_standard_cases[i];
     Parsed base_parsed;
     ParsePathURL(test_data.base, strlen(test_data.base), false, &base_parsed);

     std::string resolved;
     StdStringCanonOutput output(&resolved);
     Parsed resolved_parsed;
     bool valid = ResolveRelative(test_data.base, strlen(test_data.base),
                                  base_parsed, test_data.rel,
                                  strlen(test_data.rel), NULL, &output,
                                  &resolved_parsed);
     output.Complete();

     EXPECT_EQ(test_data.is_valid, valid) << i;
     if (test_data.is_valid && valid)
       EXPECT_EQ(test_data.out, resolved) << i;
   }
 }

 TEST_F(URLUtilTest, TestNoRefComponent) {
   // The hash-mark must be ignored when mailto: scheme is parsed,
   // even if the URL has a base and relative part.
   const char* base = "mailto://to/";
   const char* rel = "any#body";

   Parsed base_parsed;
   ParsePathURL(base, strlen(base), false, &base_parsed);

   std::string resolved;
   StdStringCanonOutput output(&resolved);
   Parsed resolved_parsed;

   bool valid = ResolveRelative(base, strlen(base),
                                base_parsed, rel,
                                strlen(rel), NULL, &output,
                                &resolved_parsed);
   EXPECT_TRUE(valid);
   EXPECT_FALSE(resolved_parsed.ref.is_valid());
 }

 TEST_F(URLUtilTest, PotentiallyDanglingMarkup) {
   struct ResolveRelativeCase {
     const char* base;
     const char* rel;
     bool potentially_dangling_markup;
     const char* out;
   } cases[] = {
       {"https://example.com/", "/path<", false, "https://example.com/path%3C"},
       {"https://example.com/", "\n/path<", true, "https://example.com/path%3C"},
       {"https://example.com/", "\r/path<", true, "https://example.com/path%3C"},
       {"https://example.com/", "\t/path<", true, "https://example.com/path%3C"},
       {"https://example.com/", "/pa\nth<", true, "https://example.com/path%3C"},
       {"https://example.com/", "/pa\rth<", true, "https://example.com/path%3C"},
       {"https://example.com/", "/pa\tth<", true, "https://example.com/path%3C"},
       {"https://example.com/", "/path\n<", true, "https://example.com/path%3C"},
       {"https://example.com/", "/path\r<", true, "https://example.com/path%3C"},
       {"https://example.com/", "/path\r<", true, "https://example.com/path%3C"},
       {"https://example.com/", "\n/<path", true, "https://example.com/%3Cpath"},
       {"https://example.com/", "\r/<path", true, "https://example.com/%3Cpath"},
       {"https://example.com/", "\t/<path", true, "https://example.com/%3Cpath"},
       {"https://example.com/", "/<pa\nth", true, "https://example.com/%3Cpath"},
       {"https://example.com/", "/<pa\rth", true, "https://example.com/%3Cpath"},
       {"https://example.com/", "/<pa\tth", true, "https://example.com/%3Cpath"},
       {"https://example.com/", "/<path\n", true, "https://example.com/%3Cpath"},
       {"https://example.com/", "/<path\r", true, "https://example.com/%3Cpath"},
       {"https://example.com/", "/<path\r", true, "https://example.com/%3Cpath"},
   };

   for (const auto& test : cases) {
     SCOPED_TRACE(::testing::Message() << test.base << ", " << test.rel);
     Parsed base_parsed;
     ParseStandardURL(test.base, strlen(test.base), &base_parsed);

     std::string resolved;
     StdStringCanonOutput output(&resolved);
     Parsed resolved_parsed;
     bool valid =
         ResolveRelative(test.base, strlen(test.base), base_parsed, test.rel,
                         strlen(test.rel), NULL, &output, &resolved_parsed);
     ASSERT_TRUE(valid);
     output.Complete();

     EXPECT_EQ(test.potentially_dangling_markup,
               resolved_parsed.potentially_dangling_markup);
     EXPECT_EQ(test.out, resolved);
   }
 }

 TEST_F(URLUtilTest, PotentiallyDanglingMarkupAfterReplacement) {
   // Parse a URL with potentially dangling markup.
   Parsed original_parsed;
   RawCanonOutput<32> original;
   const char* url = "htt\nps://example.com/<path";
   Canonicalize(url, strlen(url), false, nullptr, &original, &original_parsed);
   ASSERT_TRUE(original_parsed.potentially_dangling_markup);

   // Perform a replacement, and validate that the potentially_dangling_markup
   // flag carried over to the new Parsed object.
   Replacements<char> replacements;
   replacements.ClearRef();
   Parsed replaced_parsed;
   RawCanonOutput<32> replaced;
   ReplaceComponents(original.data(), original.length(), original_parsed,
                     replacements, nullptr, &replaced, &replaced_parsed);
   EXPECT_TRUE(replaced_parsed.potentially_dangling_markup);
 }

 TEST_F(URLUtilTest, PotentiallyDanglingMarkupAfterSchemeOnlyReplacement) {
   // Parse a URL with potentially dangling markup.
   Parsed original_parsed;
   RawCanonOutput<32> original;
   const char* url = "http://example.com/\n/<path";
   Canonicalize(url, strlen(url), false, nullptr, &original, &original_parsed);
   ASSERT_TRUE(original_parsed.potentially_dangling_markup);

   // Perform a replacement, and validate that the potentially_dangling_markup
   // flag carried over to the new Parsed object.
   Replacements<char> replacements;
   const char* new_scheme = "https";
   replacements.SetScheme(new_scheme, Component(0, strlen(new_scheme)));
   Parsed replaced_parsed;
   RawCanonOutput<32> replaced;
   ReplaceComponents(original.data(), original.length(), original_parsed,
                     replacements, nullptr, &replaced, &replaced_parsed);
   EXPECT_TRUE(replaced_parsed.potentially_dangling_markup);
 }

 TEST_F(URLUtilTest, TestDomainIs) {
   const struct {
     const char* canonicalized_host;
     const char* lower_ascii_domain;
     bool expected_domain_is;
   } kTestCases[] = {
       {"google.com", "google.com", true},
       {"www.google.com", "google.com", true},      // Subdomain is ignored.
       {"www.google.com.cn", "google.com", false},  // Different TLD.
       {"www.google.comm", "google.com", false},
       {"www.iamnotgoogle.com", "google.com", false},  // Different hostname.
       {"www.google.com", "Google.com", false},  // The input is not lower-cased.

       // If the host ends with a dot, it matches domains with or without a dot.
       {"www.google.com.", "google.com", true},
       {"www.google.com.", "google.com.", true},
       {"www.google.com.", ".com", true},
       {"www.google.com.", ".com.", true},

       // But, if the host doesn't end with a dot and the input domain does, then
       // it's considered to not match.
       {"www.google.com", "google.com.", false},

       // If the host ends with two dots, it doesn't match.
       {"www.google.com..", "google.com", false},

       // Empty parameters.
       {"www.google.com", "", false},
       {"", "www.google.com", false},
       {"", "", false},
   };

   for (const auto& test_case : kTestCases) {
     SCOPED_TRACE(testing::Message() << "(host, domain): ("
                                     << test_case.canonicalized_host << ", "
                                     << test_case.lower_ascii_domain << ")");

     EXPECT_EQ(
         test_case.expected_domain_is,
         DomainIs(test_case.canonicalized_host, test_case.lower_ascii_domain));
   }
 }

 namespace {
 absl::optional<std::string> CanonicalizeSpec(base::StringPiece spec,
                                              bool trim_path_end) {
   std::string canonicalized;
   StdStringCanonOutput output(&canonicalized);
   Parsed parsed;
   if (!Canonicalize(spec.data(), spec.size(), trim_path_end,
                     /*charset_converter=*/nullptr, &output, &parsed)) {
     return {};
   }
   output.Complete();  // Must be called before string is used.
   return canonicalized;
 }
 }  // namespace

 #if BUILDFLAG(IS_WIN)
 // Regression test for https://crbug.com/1252658.
 TEST_F(URLUtilTest, TestCanonicalizeWindowsPathWithLeadingNUL) {
   auto PrefixWithNUL = [](std::string&& s) -> std::string { return '\0' + s; };
   EXPECT_EQ(CanonicalizeSpec(PrefixWithNUL("w:"), /*trim_path_end=*/false),
             absl::make_optional("file:///W:"));
   EXPECT_EQ(CanonicalizeSpec(PrefixWithNUL("\\\\server\\share"),
                              /*trim_path_end=*/false),
             absl::make_optional("file://server/share"));
 }
 #endif

 TEST_F(URLUtilTest, TestCanonicalizeIdempotencyWithLeadingControlCharacters) {
   std::string spec = "_w:";
   // Loop over all C0 control characters and the space character.
   for (char c = '\0'; c <= ' '; c++) {
     SCOPED_TRACE(testing::Message() << "c: " << c);

     // Overwrite the first character of `spec`. Note that replacing the first
     // character with NUL will not change the length!
     spec[0] = c;

     for (bool trim_path_end : {false, true}) {
       SCOPED_TRACE(testing::Message() << "trim_path_end: " << trim_path_end);

       absl::optional<std::string> canonicalized =
           CanonicalizeSpec(spec, trim_path_end);
       ASSERT_TRUE(canonicalized);
       EXPECT_EQ(canonicalized, CanonicalizeSpec(*canonicalized, trim_path_end));
     }
   }
 }

 }  // namespace url