rippled/src/test/unit_test/FileDirGuard.h

//------------------------------------------------------------------------------
/*
This file is part of rippled: https://github.com/ripple/rippled
Copyright (c) 2018 Ripple Labs Inc.

Permission to use, copy, modify, and/or distribute this software for any
purpose  with  or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.

THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================

#ifndef TEST_UNIT_TEST_DIRGUARD_H
#define TEST_UNIT_TEST_DIRGUARD_H

#include <test/jtx/TestSuite.h>

#include <xrpl/basics/contract.h>

#include <boost/filesystem.hpp>

#include <fstream>

namespace ripple {
namespace test {
namespace detail {

/**
    Create a directory and remove it when it's done
*/
class DirGuard
{
protected:
    using path = boost::filesystem::path;

private:
    path subDir_;
    bool rmSubDir_{false};

protected:
    beast::unit_test::suite& test_;

    auto
    rmDir(path const& toRm)
    {
        if (is_directory(toRm) && is_empty(toRm))
            remove(toRm);
        else
            test_.log << "Expected " << toRm.string()
                      << " to be an empty existing directory." << std::endl;
    }

public:
    DirGuard(beast::unit_test::suite& test, path subDir, bool useCounter = true)
        : subDir_(std::move(subDir)), test_(test)
    {
        using namespace boost::filesystem;

        static auto subDirCounter = 0;
        if (useCounter)
            subDir_ += std::to_string(++subDirCounter);
        if (!exists(subDir_))
        {
            create_directory(subDir_);
            rmSubDir_ = true;
        }
        else if (is_directory(subDir_))
            rmSubDir_ = false;
        else
        {
            // Cannot run the test. Someone created a file where we want to
            // put our directory
            Throw<std::runtime_error>(
                "Cannot create directory: " + subDir_.string());
        }
    }

    ~DirGuard()
    {
        try
        {
            using namespace boost::filesystem;

            if (rmSubDir_)
                rmDir(subDir_);
        }
        catch (std::exception& e)
        {
            // if we throw here, just let it die.
            test_.log << "Error in ~DirGuard: " << e.what() << std::endl;
        };
    }

    path const&
    subdir() const
    {
        return subDir_;
    }
};

/**
    Write a file in a directory and remove when done
*/
class FileDirGuard : public DirGuard
{
protected:
    path const file_;
    bool created_ = false;

public:
    FileDirGuard(
        beast::unit_test::suite& test,
        path subDir,
        path file,
        std::string const& contents,
        bool useCounter = true,
        bool create = true)
        : DirGuard(test, subDir, useCounter)
        , file_(file.is_absolute() ? file : subdir() / file)
    {
        if (!exists(file_))
        {
            if (create)
            {
                std::ofstream o(file_.string());
                o << contents;
                created_ = true;
            }
        }
        else
        {
            Throw<std::runtime_error>(
                "Refusing to overwrite existing file: " + file_.string());
        }
    }

    ~FileDirGuard()
    {
        try
        {
            using namespace boost::filesystem;
            if (exists(file_))
            {
                remove(file_);
            }
            else
            {
                if (created_)
                    test_.log << "Expected " << file_.string()
                              << " to be an existing file." << std::endl;
            }
        }
        catch (std::exception& e)
        {
            // if we throw here, just let it die.
            test_.log << "Error in ~FileGuard: " << e.what() << std::endl;
        };
    }

    path const&
    file() const
    {
        return file_;
    }

    bool
    fileExists() const
    {
        return boost::filesystem::exists(file_);
    }
};

}  // namespace detail
}  // namespace test
}  // namespace ripple

#endif  // TEST_UNIT_TEST_DIRGUARD_H