/*
	This file is part of solidity.

	solidity is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	solidity is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
*/
// SPDX-License-Identifier: GPL-3.0

/// Unit tests for libsolidity/interface/FileReader.h

#include <libsolidity/interface/FileReader.h>

#include <test/Common.h>
#include <test/FilesystemUtils.h>
#include <test/TemporaryDirectory.h>
#include <test/libsolidity/util/SoltestErrors.h>

#include <boost/filesystem.hpp>
#include <boost/test/unit_test.hpp>

using namespace std;
using namespace solidity::test;

#define TEST_CASE_NAME (boost::unit_test::framework::current_test_case().p_name)

namespace solidity::frontend::test
{

BOOST_AUTO_TEST_SUITE(FileReaderTest)

BOOST_AUTO_TEST_CASE(normalizeCLIPathForVFS_absolute_path)
{
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/"), "/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/."), "/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/./"), "/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/./."), "/");

	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/a"), "/a");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/a/"), "/a/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/a/."), "/a/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/./a"), "/a");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/./a/"), "/a/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/./a/."), "/a/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/a/b"), "/a/b");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/a/b/"), "/a/b/");

	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/a/./b/"), "/a/b/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/a/../a/b/"), "/a/b/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/a/b/c/.."), "/a/b");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/a/b/c/../"), "/a/b/");

	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/a/b/c/../../.."), "/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/a/b/c/../../../"), "/");
}

BOOST_AUTO_TEST_CASE(normalizeCLIPathForVFS_relative_path)
{
	TemporaryDirectory tempDir({"x/y/z"}, TEST_CASE_NAME);
	TemporaryWorkingDirectory tempWorkDir(tempDir.path() / "x/y/z");

	// NOTE: If path to work dir contains symlinks (often the case on macOS), boost might resolve
	// them, making the path different from tempDirPath.
	boost::filesystem::path expectedPrefix = boost::filesystem::current_path().parent_path().parent_path().parent_path();
	// On Windows tempDir.path() normally contains the drive letter while the normalized path should not.
	expectedPrefix = "/" / expectedPrefix.relative_path();
	soltestAssert(expectedPrefix.is_absolute() || expectedPrefix.root_path() == "/", "");

	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("."), expectedPrefix / "x/y/z/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("./"), expectedPrefix / "x/y/z/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS(".//"), expectedPrefix / "x/y/z/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS(".."), expectedPrefix / "x/y");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("../"), expectedPrefix / "x/y/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("..//"), expectedPrefix / "x/y/");

	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("a"), expectedPrefix / "x/y/z/a");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("a/"), expectedPrefix / "x/y/z/a/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("a/."), expectedPrefix / "x/y/z/a/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("./a"), expectedPrefix / "x/y/z/a");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("./a/"), expectedPrefix / "x/y/z/a/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("./a/."), expectedPrefix / "x/y/z/a/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("./a/./"), expectedPrefix / "x/y/z/a/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("./a/.//"), expectedPrefix / "x/y/z/a/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("./a/./."), expectedPrefix / "x/y/z/a/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("./a/././"), expectedPrefix / "x/y/z/a/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("./a/././/"), expectedPrefix / "x/y/z/a/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("a/b"), expectedPrefix / "x/y/z/a/b");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("a/b/"), expectedPrefix / "x/y/z/a/b/");

	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("../a/b"), expectedPrefix / "x/y/a/b");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("../../a/b"), expectedPrefix / "x/a/b");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("./a/b"), expectedPrefix / "x/y/z/a/b");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("././a/b"), expectedPrefix / "x/y/z/a/b");

	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("a/./b/"), expectedPrefix / "x/y/z/a/b/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("a/../a/b/"), expectedPrefix / "x/y/z/a/b/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("a/b/c/.."), expectedPrefix / "x/y/z/a/b");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("a/b/c/../"), expectedPrefix / "x/y/z/a/b/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("a/b/c/..//"), expectedPrefix / "x/y/z/a/b/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("a/b/c/../.."), expectedPrefix / "x/y/z/a");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("a/b/c/../../"), expectedPrefix / "x/y/z/a/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("a/b/c/../..//"), expectedPrefix / "x/y/z/a/");

	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("../../a/.././../p/../q/../a/b"), expectedPrefix / "a/b");
}

BOOST_AUTO_TEST_CASE(normalizeCLIPathForVFS_redundant_slashes)
{
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("///"), "/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("////"), "/");

	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("////a/b/"), "/a/b/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/a//b/"), "/a/b/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/a////b/"), "/a/b/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/a/b//"), "/a/b/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/a/b////"), "/a/b/");
}

BOOST_AUTO_TEST_CASE(normalizeCLIPathForVFS_unc_path)
{
	TemporaryDirectory tempDir(TEST_CASE_NAME);
	TemporaryWorkingDirectory tempWorkDir(tempDir);

	// On Windows tempDir.path() normally contains the drive letter while the normalized path should not.
	boost::filesystem::path expectedWorkDir = "/" / boost::filesystem::current_path().relative_path();
	soltestAssert(expectedWorkDir.is_absolute() || expectedWorkDir.root_path() == "/", "");

	// UNC paths start with // or \\ followed by a name. They are used for network shares on Windows.
	// On UNIX systems they are not supported but still treated in a special way.
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("//host/"), "//host/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("//host/a/b"), "//host/a/b");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("//host/a/b/"), "//host/a/b/");

#if defined(_WIN32)
	// On Windows an UNC path can also start with \\ instead of //
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("\\\\host/"), "//host/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("\\\\host/a/b"), "//host/a/b");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("\\\\host/a/b/"), "//host/a/b/");
#else
	// On UNIX systems it's just a fancy relative path instead
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("\\\\host/"), expectedWorkDir / "\\\\host/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("\\\\host/a/b"), expectedWorkDir / "\\\\host/a/b");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("\\\\host/a/b/"), expectedWorkDir / "\\\\host/a/b/");
#endif
}

BOOST_AUTO_TEST_CASE(normalizeCLIPathForVFS_root_name_only)
{
	TemporaryDirectory tempDir(TEST_CASE_NAME);
	TemporaryWorkingDirectory tempWorkDir(tempDir);

	boost::filesystem::path expectedWorkDir = "/" / boost::filesystem::current_path().relative_path();
	soltestAssert(expectedWorkDir.is_absolute() || expectedWorkDir.root_path() == "/", "");

	// A root **path** consists of a directory name (typically / or \) and the root name (drive
	// letter (C:), UNC host name (//host), etc.). Either can be empty. Root path as a whole may be
	// an absolute path but root name on its own is considered relative. For example on Windows
	// C:\ represents the root directory of drive C: but C: on its own refers to the current working
	// directory.

	// UNC paths
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("//"), "//" / expectedWorkDir);
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("//host"), "//host" / expectedWorkDir);

	// On UNIX systems root name is empty.
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS(""), expectedWorkDir);

#if defined(_WIN32)
	boost::filesystem::path driveLetter = boost::filesystem::current_path().root_name();
	solAssert(!driveLetter.empty(), "");
	solAssert(driveLetter.is_relative(), "");

	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS(driveLetter), expectedWorkDir);
#endif
}

BOOST_AUTO_TEST_CASE(normalizeCLIPathForVFS_stripping_root_name)
{
	TemporaryDirectory tempDir(TEST_CASE_NAME);
	TemporaryWorkingDirectory tempWorkDir(tempDir);

	soltestAssert(boost::filesystem::current_path().is_absolute(), "");
#if defined(_WIN32)
	soltestAssert(!boost::filesystem::current_path().root_name().empty(), "");
#endif

	boost::filesystem::path normalizedPath = FileReader::normalizeCLIPathForVFS(boost::filesystem::current_path());
	BOOST_CHECK_EQUAL(normalizedPath, "/" / boost::filesystem::current_path().relative_path());
	BOOST_TEST(normalizedPath.root_name().empty());
	BOOST_CHECK_EQUAL(normalizedPath.root_directory(), "/");
}

BOOST_AUTO_TEST_CASE(normalizeCLIPathForVFS_path_beyond_root)
{
	TemporaryWorkingDirectory tempWorkDir("/");

	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/.."), "/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/../"), "/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/../."), "/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/../.."), "/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/../a"), "/a");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/../a/.."), "/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/../a/../.."), "/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/../../a"), "/a");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/../../a/.."), "/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/../../a/../.."), "/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/a/../.."), "/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("/a/../../b/../.."), "/");

	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS(".."), "/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("../"), "/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("../."), "/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("../.."), "/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("../a"), "/a");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("../a/.."), "/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("../a/../.."), "/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("../../a"), "/a");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("../../a/.."), "/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("../../a/../.."), "/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("a/../.."), "/");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("a/../../b/../.."), "/");
}

BOOST_AUTO_TEST_CASE(normalizeCLIPathForVFS_case_sensitivity)
{
	TemporaryDirectory tempDir(TEST_CASE_NAME);
	TemporaryWorkingDirectory tempWorkDir(tempDir);

	boost::filesystem::path expectedPrefix = "/" / tempDir.path().relative_path();
	soltestAssert(expectedPrefix.is_absolute() || expectedPrefix.root_path() == "/", "");

	BOOST_TEST(FileReader::normalizeCLIPathForVFS(tempDir.path() / "abc") == expectedPrefix / "abc");
	BOOST_TEST(FileReader::normalizeCLIPathForVFS(tempDir.path() / "abc") != expectedPrefix / "ABC");
	BOOST_TEST(FileReader::normalizeCLIPathForVFS(tempDir.path() / "ABC") != expectedPrefix / "abc");
	BOOST_TEST(FileReader::normalizeCLIPathForVFS(tempDir.path() / "ABC") == expectedPrefix / "ABC");
}

BOOST_AUTO_TEST_CASE(normalizeCLIPathForVFS_path_separators)
{
	// Even on Windows we want / as a separator.
	BOOST_TEST((FileReader::normalizeCLIPathForVFS("/a/b/c").native() == boost::filesystem::path("/a/b/c").native()));
}

BOOST_AUTO_TEST_CASE(normalizeCLIPathForVFS_should_not_resolve_symlinks)
{
	TemporaryDirectory tempDir({"abc/"}, TEST_CASE_NAME);
	soltestAssert(tempDir.path().is_absolute(), "");

	if (!createSymlinkIfSupportedByFilesystem(tempDir.path() / "abc", tempDir.path() / "sym", true))
		return;

	boost::filesystem::path expectedPrefix = "/" / tempDir.path().relative_path();
	soltestAssert(expectedPrefix.is_absolute() || expectedPrefix.root_path() == "/", "");

	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS(tempDir.path() / "sym/contract.sol"), expectedPrefix / "sym/contract.sol");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS(tempDir.path() / "abc/contract.sol"), expectedPrefix / "abc/contract.sol");
}

BOOST_AUTO_TEST_CASE(normalizeCLIPathForVFS_should_resolve_symlinks_in_workdir_when_path_is_relative)
{
	TemporaryDirectory tempDir({"abc/"}, TEST_CASE_NAME);
	soltestAssert(tempDir.path().is_absolute(), "");

	if (!createSymlinkIfSupportedByFilesystem(tempDir.path() / "abc", tempDir.path() / "sym", true))
		return;

	TemporaryWorkingDirectory tempWorkDir(tempDir.path() / "sym");
	boost::filesystem::path expectedWorkDir = "/" / boost::filesystem::weakly_canonical(boost::filesystem::current_path()).relative_path();
	soltestAssert(expectedWorkDir.is_absolute() || expectedWorkDir.root_path() == "/", "");

	boost::filesystem::path expectedPrefix = "/" / tempDir.path().relative_path();
	soltestAssert(expectedPrefix.is_absolute() || expectedPrefix.root_path() == "/", "");

	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS("contract.sol"), expectedWorkDir / "contract.sol");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS(tempDir.path() / "sym/contract.sol"), expectedPrefix / "sym/contract.sol");
	BOOST_CHECK_EQUAL(FileReader::normalizeCLIPathForVFS(tempDir.path() / "abc/contract.sol"), expectedPrefix / "abc/contract.sol");
}

BOOST_AUTO_TEST_CASE(isPathPrefix_file_prefix)
{
	BOOST_TEST(FileReader::isPathPrefix("/", "/contract.sol"));
	BOOST_TEST(FileReader::isPathPrefix("/contract.sol", "/contract.sol"));
	BOOST_TEST(FileReader::isPathPrefix("/contract.sol/", "/contract.sol"));
	BOOST_TEST(FileReader::isPathPrefix("/contract.sol/.", "/contract.sol"));

	BOOST_TEST(FileReader::isPathPrefix("/", "/a/bc/def/contract.sol"));
	BOOST_TEST(FileReader::isPathPrefix("/a", "/a/bc/def/contract.sol"));
	BOOST_TEST(FileReader::isPathPrefix("/a/", "/a/bc/def/contract.sol"));
	BOOST_TEST(FileReader::isPathPrefix("/a/bc", "/a/bc/def/contract.sol"));
	BOOST_TEST(FileReader::isPathPrefix("/a/bc/def/contract.sol", "/a/bc/def/contract.sol"));

	BOOST_TEST(FileReader::isPathPrefix("/", "/a/bc/def/contract.sol"));
	BOOST_TEST(FileReader::isPathPrefix("/a", "/a/bc/def/contract.sol"));
	BOOST_TEST(FileReader::isPathPrefix("/a/", "/a/bc/def/contract.sol"));
	BOOST_TEST(FileReader::isPathPrefix("/a/bc", "/a/bc/def/contract.sol"));
	BOOST_TEST(FileReader::isPathPrefix("/a/bc/def/contract.sol", "/a/bc/def/contract.sol"));

	BOOST_TEST(!FileReader::isPathPrefix("/contract.sol", "/token.sol"));
	BOOST_TEST(!FileReader::isPathPrefix("/contract", "/contract.sol"));
	BOOST_TEST(!FileReader::isPathPrefix("/contract.sol", "/contract"));
	BOOST_TEST(!FileReader::isPathPrefix("/contract.so", "/contract.sol"));
	BOOST_TEST(!FileReader::isPathPrefix("/contract.sol", "/contract.so"));

	BOOST_TEST(!FileReader::isPathPrefix("/a/b/c/contract.sol", "/a/b/contract.sol"));
	BOOST_TEST(!FileReader::isPathPrefix("/a/b/contract.sol", "/a/b/c/contract.sol"));
	BOOST_TEST(!FileReader::isPathPrefix("/a/b/c/contract.sol", "/a/b/c/d/contract.sol"));
	BOOST_TEST(!FileReader::isPathPrefix("/a/b/c/d/contract.sol", "/a/b/c/contract.sol"));
	BOOST_TEST(!FileReader::isPathPrefix("/a/b/c/contract.sol", "/contract.sol"));
}

BOOST_AUTO_TEST_CASE(isPathPrefix_directory_prefix)
{
	BOOST_TEST(FileReader::isPathPrefix("/", "/"));
	BOOST_TEST(!FileReader::isPathPrefix("/a/b/c/", "/"));
	BOOST_TEST(!FileReader::isPathPrefix("/a/b/c", "/"));

	BOOST_TEST(FileReader::isPathPrefix("/", "/a/bc/"));
	BOOST_TEST(FileReader::isPathPrefix("/a", "/a/bc/"));
	BOOST_TEST(FileReader::isPathPrefix("/a/", "/a/bc/"));
	BOOST_TEST(FileReader::isPathPrefix("/a/bc", "/a/bc/"));
	BOOST_TEST(FileReader::isPathPrefix("/a/bc/", "/a/bc/"));

	BOOST_TEST(!FileReader::isPathPrefix("/a", "/b/"));
	BOOST_TEST(!FileReader::isPathPrefix("/a/", "/b/"));
	BOOST_TEST(!FileReader::isPathPrefix("/a/contract.sol", "/a/b/"));

	BOOST_TEST(!FileReader::isPathPrefix("/a/b/c/", "/a/b/"));
	BOOST_TEST(!FileReader::isPathPrefix("/a/b/c", "/a/b/"));
}

BOOST_AUTO_TEST_CASE(isPathPrefix_unc_path)
{
	BOOST_TEST(FileReader::isPathPrefix("//host/a/b/", "//host/a/b/"));
	BOOST_TEST(FileReader::isPathPrefix("//host/a/b", "//host/a/b/"));
	BOOST_TEST(FileReader::isPathPrefix("//host/a/", "//host/a/b/"));
	BOOST_TEST(FileReader::isPathPrefix("//host/a", "//host/a/b/"));
	BOOST_TEST(FileReader::isPathPrefix("//host/", "//host/a/b/"));

	// NOTE: //host and // cannot be passed to isPathPrefix() because they are considered relative.

	BOOST_TEST(!FileReader::isPathPrefix("//host1/", "//host2/"));
	BOOST_TEST(!FileReader::isPathPrefix("//host1/a/b/", "//host2/a/b/"));

	BOOST_TEST(!FileReader::isPathPrefix("/a/b/c/", "//a/b/c/"));
	BOOST_TEST(!FileReader::isPathPrefix("//a/b/c/", "/a/b/c/"));
}

BOOST_AUTO_TEST_CASE(isPathPrefix_case_sensitivity)
{
	BOOST_TEST(!FileReader::isPathPrefix("/a.sol", "/A.sol"));
	BOOST_TEST(!FileReader::isPathPrefix("/A.sol", "/a.sol"));
	BOOST_TEST(!FileReader::isPathPrefix("/A/", "/a/"));
	BOOST_TEST(!FileReader::isPathPrefix("/a/", "/A/"));
	BOOST_TEST(!FileReader::isPathPrefix("/a/BC/def/", "/a/bc/def/contract.sol"));
}

BOOST_AUTO_TEST_CASE(stripPrefixIfPresent_file_prefix)
{
	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/", "/contract.sol"), "contract.sol");
	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/contract.sol", "/contract.sol"), ".");
	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/contract.sol/", "/contract.sol"), ".");
	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/contract.sol/.", "/contract.sol"), ".");

	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/", "/a/bc/def/contract.sol"), "a/bc/def/contract.sol");
	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/a", "/a/bc/def/contract.sol"), "bc/def/contract.sol");
	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/a/", "/a/bc/def/contract.sol"), "bc/def/contract.sol");
	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/a/bc", "/a/bc/def/contract.sol"), "def/contract.sol");
	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/a/bc/def/", "/a/bc/def/contract.sol"), "contract.sol");
	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/a/bc/def/contract.sol", "/a/bc/def/contract.sol"), ".");

	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/contract.sol", "/token.sol"), "/token.sol");
	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/contract", "/contract.sol"), "/contract.sol");
	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/contract.sol", "/contract"), "/contract");

	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/a/b/c/contract.sol", "/a/b/contract.sol"), "/a/b/contract.sol");
	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/a/b/contract.sol", "/a/b/c/contract.sol"), "/a/b/c/contract.sol");
}

BOOST_AUTO_TEST_CASE(stripPrefixIfPresent_directory_prefix)
{
	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/", "/"), ".");

	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/", "/a/bc/def/"), "a/bc/def/");
	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/a", "/a/bc/def/"), "bc/def/");
	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/a/", "/a/bc/def/"), "bc/def/");
	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/a/bc", "/a/bc/def/"), "def/");
	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/a/bc/def/", "/a/bc/def/"), ".");

	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/a", "/b/"), "/b/");
	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/a/", "/b/"), "/b/");

	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/a/b/c/", "/a/b/"), "/a/b/");
	BOOST_CHECK_EQUAL(FileReader::stripPrefixIfPresent("/a/b/c", "/a/b/"), "/a/b/");
}

BOOST_AUTO_TEST_CASE(isUNCPath)
{
	BOOST_TEST(FileReader::isUNCPath("//"));
	BOOST_TEST(FileReader::isUNCPath("//root"));
	BOOST_TEST(FileReader::isUNCPath("//root/"));

#if defined(_WIN32)
	// On Windows boost sees these as ///, which is equivalent to /
	BOOST_TEST(!FileReader::isUNCPath("//\\"));
	BOOST_TEST(!FileReader::isUNCPath("\\\\/"));
	BOOST_TEST(!FileReader::isUNCPath("\\/\\"));

	BOOST_TEST(FileReader::isUNCPath("\\\\"));
	BOOST_TEST(FileReader::isUNCPath("\\\\root"));
	BOOST_TEST(FileReader::isUNCPath("\\\\root/"));
#else
	// On UNIX it's actually an UNC path
	BOOST_TEST(FileReader::isUNCPath("//\\"));

	// On UNIX these are just weird relative directory names consisting only of backslashes.
	BOOST_TEST(!FileReader::isUNCPath("\\\\/"));
	BOOST_TEST(!FileReader::isUNCPath("\\/\\"));

	BOOST_TEST(!FileReader::isUNCPath("\\\\"));
	BOOST_TEST(!FileReader::isUNCPath("\\\\root"));
	BOOST_TEST(!FileReader::isUNCPath("\\\\root/"));
#endif

	BOOST_TEST(!FileReader::isUNCPath("\\/"));
	BOOST_TEST(!FileReader::isUNCPath("/\\"));

	BOOST_TEST(!FileReader::isUNCPath(""));
	BOOST_TEST(!FileReader::isUNCPath("."));
	BOOST_TEST(!FileReader::isUNCPath(".."));
	BOOST_TEST(!FileReader::isUNCPath("/"));
	BOOST_TEST(!FileReader::isUNCPath("a"));
	BOOST_TEST(!FileReader::isUNCPath("a/b/c"));
	BOOST_TEST(!FileReader::isUNCPath("contract.sol"));
}

BOOST_AUTO_TEST_SUITE_END()

} // namespace solidity::frontend::test