exiv2/unitTests/test_basicio.cpp

// SPDX-License-Identifier: GPL-2.0-or-later

#include <exiv2/basicio.hpp>
#include <gtest/gtest.h>

#include <array>

using namespace Exiv2;

TEST(MemIo, isNotAtEofInitially)
{
    std::array<byte, 64> buf;
    buf.fill(0);

    MemIo io(buf.data(), buf.size());
    ASSERT_FALSE(io.eof());
}

TEST(MemIo, seekBeyondBufferSizeReturns1AndSetsEofToTrue)
{
    std::array<byte, 64> buf;
    buf.fill(0);

    MemIo io(buf.data(), buf.size());
    ASSERT_EQ(1, io.seek(65, BasicIo::beg));
    ASSERT_TRUE(io.eof());
}

TEST(MemIo, seekBefore0Returns1ButItDoesNotSetEofToTrue)
{
    std::array<byte, 64> buf;
    buf.fill(0);

    MemIo io(buf.data(), buf.size());
    ASSERT_EQ(1, io.seek(-1, BasicIo::beg));
    ASSERT_FALSE(io.eof());
}

TEST(MemIo, seekBeyondBoundsDoesNotMoveThePosition)
{
    std::array<byte, 64> buf;
    buf.fill(0);

    MemIo io(buf.data(), buf.size());
    ASSERT_EQ(0, io.tell());
    ASSERT_EQ(1, io.seek(65, BasicIo::beg));
    ASSERT_EQ(0, io.tell());
}

TEST(MemIo, seekInsideBoundsMoveThePosition)
{
    std::array<byte, 64> buf;
    buf.fill(0);

    MemIo io(buf.data(), buf.size());
    ASSERT_EQ(0, io.tell());
    ASSERT_EQ(0, io.seek(32, BasicIo::beg));
    ASSERT_EQ(32, io.tell());
}

TEST(MemIo, seekInsideBoundsUsingBeg_resetsThePosition)
{
    std::array<byte, 64> buf;
    buf.fill(0);

    MemIo io(buf.data(), buf.size());
    std::vector<std::int64_t> positions {0, 8, 16, 32, 64};
    for(auto pos: positions) {
      ASSERT_EQ(0, io.seek(pos, BasicIo::beg));
      ASSERT_EQ(pos, io.tell());
    }
}

TEST(MemIo, seekInsideBoundsUsingCur_shiftThePosition)
{
    std::array<byte, 64> buf;
    buf.fill(0);

    MemIo io(buf.data(), buf.size());
    std::vector<std::int64_t> shifts {4, 4, 8, 16, 32};
    std::vector<std::int64_t> positions {4, 8, 16, 32, 64};
    for (size_t i = 0; i < shifts.size(); ++i) {
      ASSERT_EQ(0, io.seek(shifts[i], BasicIo::cur));
      ASSERT_EQ(positions[i], io.tell());
    }
}

TEST(MemIo, seekToEndPosition_doesNotTriggerEof)
{
    std::array<byte, 64> buf;
    buf.fill(0);

    MemIo io(buf.data(), buf.size());
    ASSERT_EQ(0, io.tell());
    ASSERT_EQ(0, io.seek(0, BasicIo::end));
    ASSERT_EQ(64, io.tell());
    ASSERT_FALSE(io.eof());
}

TEST(MemIo, seekToEndPositionAndReadTriggersEof)
{
    std::array<byte, 64> buf;
    buf.fill(0);

    MemIo io(buf.data(), buf.size());
    ASSERT_EQ(0, io.seek(0, BasicIo::end));
    ASSERT_EQ(64, io.tell());

    std::array<byte, 64> buf2;
    buf2.fill(0);
    ASSERT_EQ(0, io.read(buf2.data(), 1)); // Note that we cannot even read 1 byte being at the end
    ASSERT_TRUE(io.eof());
}

TEST(MemIo, readEmptyIoReturns0)
{
    std::array<byte, 10> buf;
    MemIo io;
    ASSERT_EQ(0, io.read(buf.data(), buf.size()));
}

TEST(MemIo, readLessBytesThanAvailableReturnsRequestedBytes)
{
    std::array<byte, 10> buf1, buf2;
    buf1.fill(1);
    buf2.fill(0);

    MemIo io(buf1.data(), buf1.size());
    ASSERT_EQ(5, io.read(buf2.data(), 5));
}

TEST(MemIo, readSameBytesThanAvailableReturnsRequestedBytes)
{
    std::array<byte, 10> buf1, buf2;
    buf1.fill(1);
    buf2.fill(0);

    MemIo io(buf1.data(), buf1.size());
    ASSERT_EQ(10, io.read(buf2.data(), 10));
}

TEST(MemIo, readMoreBytesThanAvailableReturnsAvailableBytes)
{
    std::array<byte, 10> buf1, buf2;
    buf1.fill(1);
    buf2.fill(0);

    MemIo io(buf1.data(), buf1.size());
    ASSERT_EQ(10, io.read(buf2.data(), 15));
}