// Copyright 2011 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "components/url_formatter/url_fixer.h"

#include <stddef.h>
#include <stdlib.h>

#include <array>
#include <string>
#include <string_view>

#include "base/base_paths.h"
#include "base/files/file_path.h"
#include "base/files/file_util.h"
#include "base/files/scoped_temp_dir.h"
#include "base/strings/strcat.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversions.h"
#include "build/build_config.h"
#include "net/base/filename_util.h"
#include "testing/gtest/include/gtest/gtest.h"
#include "url/gurl.h"
#include "url/third_party/mozilla/url_parse.h"

namespace url_formatter {

struct SegmentCase {
  std::string_view input;
  std::string_view result;
  const url::Component scheme;
  const url::Component username;
  const url::Component password;
  const url::Component host;
  const url::Component port;
  const url::Component path;
  const url::Component query;
  const url::Component ref;
};

constexpr auto kSegmentCases = std::to_array<SegmentCase>({
    {
        .input = "http://www.google.com/",
        .result = "http",
        .scheme = url::Component(0, 4),
        .username = url::Component(),
        .password = url::Component(),
        .host = url::Component(7, 14),
        .port = url::Component(),
        .path = url::Component(21, 1),
        .query = url::Component(),
        .ref = url::Component(),
    },
    {
        .input = "aBoUt:vErSiOn",
        .result = "about",
        .scheme = url::Component(0, 5),
        .username = url::Component(),
        .password = url::Component(),
        .host = url::Component(6, 7),
        .port = url::Component(),
        .path = url::Component(),
        .query = url::Component(),
        .ref = url::Component(),
    },
    {
        .input = "about:host/path?query#ref",
        .result = "about",
        .scheme = url::Component(0, 5),
        .username = url::Component(),
        .password = url::Component(),
        .host = url::Component(6, 4),
        .port = url::Component(),
        .path = url::Component(10, 5),
        .query = url::Component(16, 5),
        .ref = url::Component(22, 3),
    },
    {
        .input = "about://host/path?query#ref",
        .result = "about",
        .scheme = url::Component(0, 5),
        .username = url::Component(),
        .password = url::Component(),
        .host = url::Component(8, 4),
        .port = url::Component(),
        .path = url::Component(12, 5),
        .query = url::Component(18, 5),
        .ref = url::Component(24, 3),
    },
    {
        .input = "chrome:host/path?query#ref",
        .result = "chrome",
        .scheme = url::Component(0, 6),
        .username = url::Component(),
        .password = url::Component(),
        .host = url::Component(7, 4),
        .port = url::Component(),
        .path = url::Component(11, 5),
        .query = url::Component(17, 5),
        .ref = url::Component(23, 3),
    },
    {
        .input = "chrome://host/path?query#ref",
        .result = "chrome",
        .scheme = url::Component(0, 6),
        .username = url::Component(),
        .password = url::Component(),
        .host = url::Component(9, 4),
        .port = url::Component(),
        .path = url::Component(13, 5),
        .query = url::Component(19, 5),
        .ref = url::Component(25, 3),
    },
    {
        .input = "    www.google.com:124?foo#",
        .result = "http",
        .scheme = url::Component(),
        .username = url::Component(),
        .password = url::Component(),
        .host = url::Component(4, 14),
        .port = url::Component(19, 3),
        .path = url::Component(),
        .query = url::Component(23, 3),
        .ref = url::Component(27, 0),
    },
    {
        .input = " \u00A0 www.google.com",
        .result = "http",
        .scheme = url::Component(),
        .username = url::Component(),
        .password = url::Component(),
        .host = url::Component(4, 14),
        .port = url::Component(),
        .path = url::Component(),
        .query = url::Component(),
        .ref = url::Component(),
    },
    {
        .input = "user@www.google.com",
        .result = "http",
        .scheme = url::Component(),
        .username = url::Component(0, 4),
        .password = url::Component(),
        .host = url::Component(5, 14),
        .port = url::Component(),
        .path = url::Component(),
        .query = url::Component(),
        .ref = url::Component(),
    },
    {
        .input = "ftp:/user:P:a$$Wd@..ftp.google.com...::23///pub?foo#bar",
        .result = "ftp",
        .scheme = url::Component(0, 3),
        .username = url::Component(5, 4),
        .password = url::Component(10, 7),
        .host = url::Component(18, 20),
        .port = url::Component(39, 2),
        .path = url::Component(41, 6),
        .query = url::Component(48, 3),
        .ref = url::Component(52, 3),
    },
    {
        .input = "[2001:db8::1]/path",
        .result = "http",
        .scheme = url::Component(),
        .username = url::Component(),
        .password = url::Component(),
        .host = url::Component(0, 13),
        .port = url::Component(),
        .path = url::Component(13, 5),
        .query = url::Component(),
        .ref = url::Component(),
    },
    {
        .input = "[::1]",
        .result = "http",
        .scheme = url::Component(),
        .username = url::Component(),
        .password = url::Component(),
        .host = url::Component(0, 5),
        .port = url::Component(),
        .path = url::Component(),
        .query = url::Component(),
        .ref = url::Component(),
    },
    // Incomplete IPv6 addresses (will not canonicalize).
    {
        .input = "[2001:4860:",
        .result = "http",
        .scheme = url::Component(),
        .username = url::Component(),
        .password = url::Component(),
        .host = url::Component(0, 11),
        .port = url::Component(),
        .path = url::Component(),
        .query = url::Component(),
        .ref = url::Component(),
    },
    {
        .input = "[2001:4860:/foo",
        .result = "http",
        .scheme = url::Component(),
        .username = url::Component(),
        .password = url::Component(),
        .host = url::Component(0, 11),
        .port = url::Component(),
        .path = url::Component(11, 4),
        .query = url::Component(),
        .ref = url::Component(),
    },
    {
        .input = "http://:b005::68]",
        .result = "http",
        .scheme = url::Component(0, 4),
        .username = url::Component(),
        .password = url::Component(),
        .host = url::Component(7, 10),
        .port = url::Component(),
        .path = url::Component(),
        .query = url::Component(),
        .ref = url::Component(),
    },
    {
        .input = ":b005::68]",
        .result = "http",
        .scheme = url::Component(),
        .username = url::Component(),
        .password = url::Component(),
        .host = url::Component(1, 9),
        .port = url::Component(),
        .path = url::Component(),
        .query = url::Component(),
        .ref = url::Component(),
    },
    {
        .input = "file://host/path/file#ref",
        .result = "file",
        .scheme = url::Component(0, 4),
        .username = url::Component(),
        .password = url::Component(),
        .host = url::Component(7, 4),
        .port = url::Component(),
        .path = url::Component(11, 10),
        .query = url::Component(),
        .ref = url::Component(22, 3),
    },
    {
        .input = "file:///notahost/path/file#ref",
        .result = "file",
        .scheme = url::Component(0, 4),
        .username = url::Component(),
        .password = url::Component(),
        .host = url::Component(),
        .port = url::Component(),
        .path = url::Component(7, 19),
        .query = url::Component(),
        .ref = url::Component(27, 3),
    },
#if BUILDFLAG(IS_WIN)
    {
        .input = "c:/notahost/path/file#ref",
        .result = "file",
        .scheme = url::Component(),
        .username = url::Component(),
        .password = url::Component(),
        .host = url::Component(),
        .port = url::Component(),
        .path = url::Component(0, 21),
        .query = url::Component(),
        .ref = url::Component(22, 3),
    },
#elif BUILDFLAG(IS_POSIX)
    {
        .input = "~/notahost/path/file#ref",
        .result = "file",
        .scheme = url::Component(),
        .username = url::Component(),
        .password = url::Component(),
        .host = url::Component(),
        .port = url::Component(),
        .path = url::Component(0, 20),
        .query = url::Component(),
        .ref = url::Component(21, 3),
    },
#endif
    {
        .input = "devtools://bundled/devtools/inspector.html?ws=localhost:9221",
        .result = "devtools",
        .scheme = url::Component(0, 8),
        .username = url::Component(),
        .password = url::Component(),
        .host = url::Component(11, 7),
        .port = url::Component(),
        .path = url::Component(18, 24),
        .query = url::Component(43, 17),
        .ref = url::Component(),
    },
});

typedef testing::Test URLFixerTest;

TEST(URLFixerTest, SegmentURL) {
  std::string result;
  url::Parsed parts;

  for (size_t i = 0; i < std::size(kSegmentCases); ++i) {
    SegmentCase value = kSegmentCases[i];
    SCOPED_TRACE(testing::Message() << "test #" << i << ": " << value.input);

    result = SegmentURL(value.input, &parts);
    EXPECT_EQ(value.result, result);
    EXPECT_EQ(value.scheme, parts.scheme);
    EXPECT_EQ(value.username, parts.username);
    EXPECT_EQ(value.password, parts.password);
    EXPECT_EQ(value.host, parts.host);
    EXPECT_EQ(value.port, parts.port);
    EXPECT_EQ(value.path, parts.path);
    EXPECT_EQ(value.query, parts.query);
    EXPECT_EQ(value.ref, parts.ref);
  }
}

// Creates a file and returns its full name as well as the decomposed
// version. Example:
//    full_path = "c:\foo\bar.txt"
//    dir = "c:\foo"
//    file_name = "bar.txt"
static bool MakeTempFile(const base::FilePath& dir,
                         const base::FilePath& file_name,
                         base::FilePath* full_path) {
  *full_path = dir.Append(file_name);
  return base::WriteFile(*full_path, "");
}

// Returns true if the given URL is a file: URL that matches the given file
static bool IsMatchingFileURL(const std::string& url,
                              const base::FilePath& full_file_path) {
  if (url.length() <= 8) {
    return false;
  }
  if (std::string("file:///") != url.substr(0, 8)) {
    return false;  // no file:/// prefix
  }
  if (url.find('\\') != std::string::npos) {
    return false;  // contains backslashes
  }

  base::FilePath derived_path;
  net::FileURLToFilePath(GURL(url), &derived_path);

  return base::FilePath::CompareEqualIgnoreCase(derived_path.value(),
                                                full_file_path.value());
}

struct FixupCase {
  const std::string input;
  const std::string output;
} fixup_cases[] = {
    {"www.google.com", "http://www.google.com/"},
    {" www.google.com     ", "http://www.google.com/"},
    {" foo.com/asdf  bar", "http://foo.com/asdf%20%20bar"},
    {"..www.google.com..", "http://www.google.com./"},
    {"http://......", "http://....../"},
    {"http://host.com:ninety-two/", "http://host.com:ninety-two/"},
    {"http://host.com:ninety-two?foo", "http://host.com:ninety-two/?foo"},
    {"google.com:123", "http://google.com:123/"},
    {"about:", "chrome://version/"},
    {"about:foo", "chrome://foo/"},
    {"about:version", "chrome://version/"},
    {"about:blank", "about:blank"},
    {"About:blaNk", "about:blank"},
    {"about:blank#blah", "about:blank#blah"},
    {"about:blank/#blah", "about:blank/#blah"},
    {"about:srcdoc", "about:srcdoc"},
    {"about:srcdoc#blah", "about:srcdoc#blah"},
    {"about:srcdoc/#blah", "about:srcdoc/#blah"},
    {"about:usr:pwd@hst:20/pth?qry#ref", "chrome://hst/pth?qry#ref"},
    {"about://usr:pwd@hst/pth?qry#ref", "chrome://hst/pth?qry#ref"},
    {"chrome:usr:pwd@hst/pth?qry#ref", "chrome://hst/pth?qry#ref"},
    {"chrome://usr:pwd@hst/pth?qry#ref", "chrome://hst/pth?qry#ref"},
    {"www:123", "http://www:123/"},
    {"   www:123", "http://www:123/"},
    {"www.google.com?foo", "http://www.google.com/?foo"},
    {"www.google.com#foo", "http://www.google.com/#foo"},
    {"www.google.com?", "http://www.google.com/?"},
    {"www.google.com#", "http://www.google.com/#"},
    {"www.google.com:123?foo#bar", "http://www.google.com:123/?foo#bar"},
    {"user@www.google.com", "http://user@www.google.com/"},
    {"\xE6\xB0\xB4.com", "http://xn--1rw.com/"},
    // It would be better if this next case got treated as http, but I don't see
    // a clean way to guess this isn't the new-and-exciting "user" scheme.
    {"user:passwd@www.google.com:8080/", "user:passwd@www.google.com:8080/"},
    // {"file:///c:/foo/bar%20baz.txt", "file:///C:/foo/bar%20baz.txt"},
    // URLs which end with 0x85 (NEL in ISO-8859).
    {"http://example.com/s?q=\xD0\x85", "http://example.com/s?q=%D0%85"},
    {"http://example.com/s?q=\xEC\x97\x85", "http://example.com/s?q=%EC%97%85"},
    {"http://example.com/s?q=\xF0\x90\x80\x85",
     "http://example.com/s?q=%F0%90%80%85"},
    // URLs which end with 0xA0 (non-break space in ISO-8859).
    {"http://example.com/s?q=\xD0\xA0", "http://example.com/s?q=%D0%A0"},
    {"http://example.com/s?q=\xEC\x97\xA0", "http://example.com/s?q=%EC%97%A0"},
    {"http://example.com/s?q=\xF0\x90\x80\xA0",
     "http://example.com/s?q=%F0%90%80%A0"},
    // URLs containing Unicode non-characters.
    {"http://example.com/s?q=\xEF\xB7\x90",  // U+FDD0
     "http://example.com/s?q=%EF%B7%90"},
    {"http://example.com/s?q=\xEF\xBF\xBE",  // U+FFFE
     "http://example.com/s?q=%EF%BF%BE"},
    {"http://example.com/s?q=\xEF\xBF\xBF",  // U+FFFF
     "http://example.com/s?q=%EF%BF%BF"},
    {"http://example.com/s?q=\xF4\x8F\xBF\xBE",  // U+10FFFE
     "http://example.com/s?q=%F4%8F%BF%BE"},
    {"http://example.com/s?q=\xF4\x8F\xBF\xBF",  // U+10FFFF
     "http://example.com/s?q=%F4%8F%BF%BF"},

    // URLs containing IPv6 literals.
    {"[2001:db8::2]", "http://[2001:db8::2]/"},
    {"[::]:80", "http://[::]/"},
    {"[::]:80/path", "http://[::]/path"},
    {"[::]:180/path", "http://[::]:180/path"},
    // TODO(pmarks): Maybe we should parse bare IPv6 literals someday. Currently
    // the first colon is treated as a scheme separator, and we default
    // unspecified schemes to "http".
    {"::1", "http://:1/"},
    // Semicolon as scheme separator for standard schemes.
    {"http;//www.google.com/", "http://www.google.com/"},
    {"about;help", "chrome://help/"},
    // Semicolon in non-standard schemes is not replaced by colon.
    {"whatsup;//fool", "http://whatsup;//fool"},
    // Semicolon left as-is in URL itself.
    {"http://host/port?query;moar", "http://host/port?query;moar"},
    // Fewer slashes than expected.
    {"http;www.google.com/", "http://www.google.com/"},
    {"http;/www.google.com/", "http://www.google.com/"},
    // Semicolon at start.
    {";http://www.google.com/", "http://;http//www.google.com/"},
    // DevTools scheme.
    {"devtools://bundled/devtools/node.html",
     "devtools://bundled/devtools/node.html"},
    // DevTools scheme with websocket query.
    {"devtools://bundled/devtools/inspector.html?ws=ws://localhost:9222/guid",
     "devtools://bundled/devtools/inspector.html?ws=ws://localhost:9222/guid"},
    // host:123 should be rewritten to http://host:123/, but only if the port
    // number is valid - in particular telephone numbers are not port numbers
    // (see also SendTabToSelfUtilTest.ShouldNotOfferFeatureForTelephoneLink).
    {"host:123", "http://host:123/"},
    {"host:80", "http://host/"},  // default port is removed
    {"host:9999", "http://host:9999/"},
    {"host:00009999", "http://host:9999/"},  // leading zeros are removed
    {"host:0", "http://host:0/"},            // min valid port
    {"host:65535", "http://host:65535/"},    // max valid port
    {"host:-1", "host:-1"},
    {"host:65536", "host:65536"},
    {"host:18446744073709551619", "host:18446744073709551619"},  // > uint64.max
    {"host:", "host:"},
    {"host: 123", "host: 123"},
    {"host:+123", "host:+123"},
    {"host:1.23", "host:1.23"},
    {"host:x", "host:x"},
    {"host:᠐", "host:%E1%A0%90"},     // non-ASCII digit (U+1810)
    {"host:𝟨", "host:%F0%9D%9F%A8"},  // non-ASCII digit (U+1D7E8)
    {"tel:12345678901", "tel:12345678901"},
    {"tel:123-456-78901", "tel:123-456-78901"},
    // Double colon after host should not convert to an empty port.
    {"foo.com::/server-redirect?http%3A%2F%2Fbar.com%2Ftitle2.html",
     "http://foo.com/server-redirect?http%3A%2F%2Fbar.com%2Ftitle2.html"},
};

TEST(URLFixerTest, FixupURL) {
  for (const auto& value : fixup_cases) {
    GURL actual_output = FixupURL(value.input);
    EXPECT_EQ(value.output, actual_output.possibly_invalid_spec())
        << "input: " << value.input;

    // Fixup URL should never translate a valid GURL into an invalid one.
    if (GURL(value.input).is_valid()) {
      EXPECT_TRUE(actual_output.is_valid());
    }
  }

  // Check the TLD-appending functionality.
  FixupCase tld_cases[] = {
      {"somedomainthatwillnotbeagtld",
       "http://www.somedomainthatwillnotbeagtld.com/"},
      {"somedomainthatwillnotbeagtld.",
       "http://www.somedomainthatwillnotbeagtld.com/"},
      {"somedomainthatwillnotbeagtld..",
       "http://www.somedomainthatwillnotbeagtld.com/"},
      {".somedomainthatwillnotbeagtld",
       "http://www.somedomainthatwillnotbeagtld.com/"},
      {"www.somedomainthatwillnotbeagtld",
       "http://www.somedomainthatwillnotbeagtld.com/"},
      {"somedomainthatwillnotbeagtld.com",
       "http://somedomainthatwillnotbeagtld.com/"},
      {"http://somedomainthatwillnotbeagtld",
       "http://www.somedomainthatwillnotbeagtld.com/"},
      {"..somedomainthatwillnotbeagtld..",
       "http://www.somedomainthatwillnotbeagtld.com/"},
      {"http://www.somedomainthatwillnotbeagtld",
       "http://www.somedomainthatwillnotbeagtld.com/"},
      {"9999999999999999", "http://www.9999999999999999.com/"},
      {"somedomainthatwillnotbeagtld/foo",
       "http://www.somedomainthatwillnotbeagtld.com/foo"},
      {"somedomainthatwillnotbeagtld.com/foo",
       "http://somedomainthatwillnotbeagtld.com/foo"},
      {"somedomainthatwillnotbeagtld/?foo=.com",
       "http://www.somedomainthatwillnotbeagtld.com/?foo=.com"},
      {"www.somedomainthatwillnotbeagtld/?foo=www.",
       "http://www.somedomainthatwillnotbeagtld.com/?foo=www."},
      {"somedomainthatwillnotbeagtld.com/?foo=.com",
       "http://somedomainthatwillnotbeagtld.com/?foo=.com"},
      {"http://www.somedomainthatwillnotbeagtld.com",
       "http://www.somedomainthatwillnotbeagtld.com/"},
      {"somedomainthatwillnotbeagtld:123",
       "http://www.somedomainthatwillnotbeagtld.com:123/"},
      {"http://somedomainthatwillnotbeagtld:123",
       "http://www.somedomainthatwillnotbeagtld.com:123/"},
  };
  for (const auto& value : tld_cases) {
    EXPECT_EQ(value.output,
              FixupURL(value.input, "com").possibly_invalid_spec());
  }
}

// Test different types of file inputs to URIFixerUpper::FixupURL. This
// doesn't go into the nice array of fixups above since the file input
// has to exist.
TEST(URLFixerTest, FixupFile) {
  // this "original" filename is the one we tweak to get all the variations
  base::ScopedTempDir temp_dir_;
  ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
  base::FilePath original;
  ASSERT_TRUE(MakeTempFile(
      temp_dir_.GetPath(),
      base::FilePath(FILE_PATH_LITERAL("url fixer upper existing file.txt")),
      &original));

  // reference path
  GURL golden(net::FilePathToFileURL(original));

  // c:\foo\bar.txt -> file:///c:/foo/bar.txt (basic)
  GURL fixedup(FixupURL(original.AsUTF8Unsafe(), ""));
  EXPECT_EQ(golden, fixedup);

  // TODO(port): Make some equivalent tests for posix.
#if BUILDFLAG(IS_WIN)
  // c|/foo\bar.txt -> file:///c:/foo/bar.txt (pipe allowed instead of colon)
  std::string cur(base::WideToUTF8(original.value()));
  EXPECT_EQ(':', cur[1]);
  cur[1] = '|';
  EXPECT_EQ(golden, FixupURL(cur, ""));

  FixupCase cases[] = {
      {"c:\\Non-existent%20file.txt", "file:///C:/Non-existent%2520file.txt"},

      // \\foo\bar.txt -> file://foo/bar.txt
      // UNC paths, this file won't exist, but since there are no escapes, it
      // should be returned just converted to a file: URL.
      {"\\\\NonexistentHost\\foo\\bar.txt",
       "file://nonexistenthost/foo/bar.txt"},
      // We do this strictly, like IE8, which only accepts this form using
      // backslashes and not forward ones.  Turning "//foo" into "http" matches
      // Firefox and IE, silly though it may seem (it falls out of adding "http"
      // as the default protocol if you haven't entered one).
      {"//NonexistentHost\\foo/bar.txt", "http://nonexistenthost/foo/bar.txt"},
      {"file:///C:/foo/bar", "file:///C:/foo/bar"},

      // Much of the work here comes from GURL's canonicalization stage.
      {"file://C:/foo/bar", "file:///C:/foo/bar"},
      {"file:c:", "file:///C:"},
      {"file:c:WINDOWS", "file:///C:/WINDOWS"},
      {"file:c|Program Files", "file:///C:/Program%20Files"},
      {"file:/file", "file://file/"},
      {"file:////////c:\\foo", "file:///C:/foo"},
      {"file://server/folder/file", "file://server/folder/file"},

      // These are fixups we don't do, but could consider:
      //   {"file:///foo:/bar", "file://foo/bar"},
      //   {"file:/\\/server\\folder/file", "file://server/folder/file"},
  };
#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)

#if BUILDFLAG(IS_APPLE)
#define HOME "/Users/"
#else
#define HOME "/home/"
#endif
  home_directory_override = "/foo";
  FixupCase cases[] = {
      // File URLs go through GURL, which tries to escape intelligently.
      {"/A%20non-existent file.txt", "file:///A%2520non-existent%20file.txt"},
      // A plain "/" refers to the root.
      {"/", "file:///"},

      // These rely on the above home_directory_override.
      {"~", "file:///foo"},
      {"~/bar", "file:///foo/bar"},

      // References to other users' homedirs.
      {"~foo", "file://" HOME "foo"},
      {"~x/blah", "file://" HOME "x/blah"},
  };
#endif

  for (const auto& value : cases) {
    EXPECT_EQ(value.output, FixupURL(value.input, "").possibly_invalid_spec());
  }

  EXPECT_TRUE(base::DeleteFile(original));
}

TEST(URLFixerTest, FixupRelativeFile) {
  base::FilePath full_path;
  base::FilePath file_part(
      FILE_PATH_LITERAL("url_fixer_upper_existing_file.txt"));
  base::ScopedTempDir temp_dir_;
  ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
  ASSERT_TRUE(MakeTempFile(temp_dir_.GetPath(), file_part, &full_path));
  full_path = base::MakeAbsoluteFilePath(full_path);
  ASSERT_FALSE(full_path.empty());

  // make sure we pass through good URLs
  for (const auto& value : fixup_cases) {
    base::FilePath input = base::FilePath::FromUTF8Unsafe(value.input);
    EXPECT_EQ(
        value.output,
        FixupRelativeFile(temp_dir_.GetPath(), input).possibly_invalid_spec())
        << "input: " << value.input;
  }

  // make sure the existing file got fixed-up to a file URL, and that there
  // are no backslashes
  EXPECT_TRUE(IsMatchingFileURL(
      FixupRelativeFile(temp_dir_.GetPath(), file_part).possibly_invalid_spec(),
      full_path));
  EXPECT_TRUE(base::DeleteFile(full_path));

  // create a filename we know doesn't exist and make sure it doesn't get
  // fixed up to a file URL
  base::FilePath nonexistent_file(
      FILE_PATH_LITERAL("url_fixer_upper_nonexistent_file.txt"));
  std::string fixedup(FixupRelativeFile(temp_dir_.GetPath(), nonexistent_file)
                          .possibly_invalid_spec());
  EXPECT_NE(std::string("file:///"), fixedup.substr(0, 8));
  EXPECT_FALSE(IsMatchingFileURL(fixedup, nonexistent_file));

  // make a subdir to make sure relative paths with directories work, also
  // test spaces:
  // "app_dir\url fixer-upper dir\url fixer-upper existing file.txt"
  base::FilePath sub_dir(FILE_PATH_LITERAL("url fixer-upper dir"));
  base::FilePath sub_file(
      FILE_PATH_LITERAL("url fixer-upper existing file.txt"));
  base::FilePath new_dir = temp_dir_.GetPath().Append(sub_dir);
  base::CreateDirectory(new_dir);
  ASSERT_TRUE(MakeTempFile(new_dir, sub_file, &full_path));
  full_path = base::MakeAbsoluteFilePath(full_path);
  ASSERT_FALSE(full_path.empty());

  // test file in the subdir
  base::FilePath relative_file = sub_dir.Append(sub_file);
  EXPECT_TRUE(
      IsMatchingFileURL(FixupRelativeFile(temp_dir_.GetPath(), relative_file)
                            .possibly_invalid_spec(),
                        full_path));

  // test file in the subdir with different slashes and escaping.
  base::FilePath::StringType relative_file_str =
      sub_dir.value() + FILE_PATH_LITERAL("/") + sub_file.value();
  base::ReplaceSubstringsAfterOffset(
      &relative_file_str, 0, FILE_PATH_LITERAL(" "), FILE_PATH_LITERAL("%20"));
  EXPECT_TRUE(IsMatchingFileURL(
      FixupRelativeFile(temp_dir_.GetPath(), base::FilePath(relative_file_str))
          .possibly_invalid_spec(),
      full_path));

  // test relative directories and duplicate slashes
  // (should resolve to the same file as above)
  relative_file_str = sub_dir.value() + FILE_PATH_LITERAL("/../") +
                      sub_dir.value() + FILE_PATH_LITERAL("///./") +
                      sub_file.value();
  EXPECT_TRUE(IsMatchingFileURL(
      FixupRelativeFile(temp_dir_.GetPath(), base::FilePath(relative_file_str))
          .possibly_invalid_spec(),
      full_path));

  // done with the subdir
  EXPECT_TRUE(base::DeleteFile(full_path));
  EXPECT_TRUE(base::DeletePathRecursively(new_dir));

  // Test that an obvious HTTP URL isn't accidentally treated as an absolute
  // file path (on account of system-specific craziness).
  base::FilePath empty_path;
  base::FilePath http_url_path(FILE_PATH_LITERAL("http://../"));
  EXPECT_TRUE(FixupRelativeFile(empty_path, http_url_path).SchemeIs("http"));
}

// Declare FixupHost here so that we can test it in this file.
void FixupHost(std::string domain,
               const std::string& desired_tld,
               std::string* url);

TEST(URLFixerTest, FixupHost) {
  struct {
    const std::string domain;
    const std::string desired_tld;
    const std::string expected_output;
  } cases[] = {
      // No TLD.
      {"www.example.com", "", "www.example.com"},
      {"..www.example.com", "", "www.example.com"},
      {"www.example.com..", "", "www.example.com."},
      {".www.example.com.", "", "www.example.com."},
      {"...", "", "..."},

      // Add TLD.
      {"example", "com", "www.example.com"},
      {"example.", "com", "www.example.com"},
      {"example..", "com", "www.example.com"},
      {".example", "com", "www.example.com"},
      {"www.example", "com", "www.example.com"},
      {"example.com", "com", "example.com"},
  };

  for (const auto& value : cases) {
    std::string prefix = base::StrCat({"test case '", value.domain, "': "});
    std::string output = prefix;
    FixupHost(value.domain, value.desired_tld, &output);
    EXPECT_EQ(prefix + value.expected_output, output)
        << "input: " << value.domain;
  }
}

}  // namespace url_formatter