ladybird/AK/Tests/TestCircularDuplexStream.cpp

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#include <AK/TestSuite.h>

#include <AK/CircularDuplexStream.h>

TEST_CASE(works_like_a_queue)
{
    constexpr size_t capacity = 32;

    CircularQueue<u8, capacity> queue;
    CircularDuplexStream<capacity> stream;

    for (size_t idx = 0; idx < capacity; ++idx) {
        queue.enqueue(static_cast<u8>(idx % 256));
        stream << static_cast<u8>(idx % 256);
    }

    for (size_t idx = 0; idx < capacity; ++idx) {
        u8 byte;
        stream >> byte;

        EXPECT_EQ(queue.dequeue(), byte);
    }

    EXPECT(stream.eof());
}

TEST_CASE(overwritting_is_well_defined)
{
    constexpr size_t half_capacity = 16;
    constexpr size_t capacity = 2 * half_capacity;

    CircularDuplexStream<capacity> stream;

    for (size_t idx = 0; idx < capacity; ++idx)
        stream << static_cast<u8>(idx % 256);

    u8 bytes[half_capacity];

    stream >> Bytes { bytes, sizeof(bytes) };

    for (size_t idx = 0; idx < half_capacity; ++idx)
        EXPECT_EQ(bytes[idx], idx % 256);

    for (size_t idx = 0; idx < half_capacity; ++idx)
        stream << static_cast<u8>(idx % 256);

    for (size_t idx = 0; idx < capacity; ++idx) {
        u8 byte;
        stream >> byte;

        if (idx < half_capacity)
            EXPECT_EQ(byte, half_capacity + idx % 256);
        else
            EXPECT_EQ(byte, idx % 256 - half_capacity);
    }

    EXPECT(stream.eof());
}

TEST_CASE(of_by_one)
{
    constexpr size_t half_capacity = 32;
    constexpr size_t capacity = half_capacity * 2;

    CircularDuplexStream<capacity> stream;

    for (size_t idx = 0; idx < half_capacity; ++idx)
        stream << static_cast<u8>(0);

    for (size_t idx = 0; idx < half_capacity; ++idx)
        stream << static_cast<u8>(1);

    stream.discard_or_error(capacity);

    for (size_t idx = 0; idx < capacity; ++idx) {
        u8 byte;
        stream.read({ &byte, sizeof(byte) }, capacity);
        stream << byte;

        if (idx < half_capacity)
            EXPECT_EQ(byte, 0);
        else
            EXPECT_EQ(byte, 1);
    }
}

TEST_MAIN(CircularDuplexStream)