coinjoin_dstxmanager_tests.cpp

// Copyright (c) 2025 The Dash Core developers
// Distributed under the MIT/X11 software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include <test/util/setup_common.h>

#include <chain.h>
#include <coinjoin/coinjoin.h>
#include <coinjoin/common.h>
#include <script/script.h>
#include <uint256.h>

#include <algorithm>
#include <array>
#include <vector>

#include <boost/test/unit_test.hpp>

BOOST_FIXTURE_TEST_SUITE(coinjoin_dstxmanager_tests, TestingSetup)

static CCoinJoinBroadcastTx MakeDSTX(int vin_vout_count = 3)
{
    CCoinJoinBroadcastTx dstx;
    CMutableTransaction mtx;
    const int count = std::max(vin_vout_count, 1);
    for (int i = 0; i < count; ++i) {
        mtx.vin.emplace_back(COutPoint(uint256S("0a"), i));
        // Use denominated P2PKH outputs
        CScript spk;
        spk << OP_DUP << OP_HASH160 << std::vector<unsigned char>(20, i) << OP_EQUALVERIFY << OP_CHECKSIG;
        mtx.vout.emplace_back(CoinJoin::GetSmallestDenomination(), spk);
    }
    dstx.tx = MakeTransactionRef(mtx);
    dstx.m_protxHash = uint256::ONE;
    return dstx;
}

BOOST_AUTO_TEST_CASE(add_get_dstx)
{
    CCoinJoinBroadcastTx dstx = MakeDSTX();
    auto& man = *Assert(m_node.dstxman);
    // Not present initially
    BOOST_CHECK(!man.GetDSTX(dstx.tx->GetHash()));
    // Add
    man.AddDSTX(dstx);
    // Fetch back
    auto got = man.GetDSTX(dstx.tx->GetHash());
    BOOST_CHECK(static_cast<bool>(got));
    BOOST_CHECK_EQUAL(got.tx->GetHash().ToString(), dstx.tx->GetHash().ToString());
}

BOOST_AUTO_TEST_CASE(broadcasttx_expiry_height_logic)
{
    // Build a valid-looking CCoinJoinBroadcastTx with confirmed height
    CCoinJoinBroadcastTx dstx;
    {
        CMutableTransaction mtx;
        const int participants = std::max(3, CoinJoin::GetMinPoolParticipants());
        for (int i = 0; i < participants; ++i) {
            mtx.vin.emplace_back(COutPoint(uint256::TWO, i));
            CScript spk;
            spk << OP_DUP << OP_HASH160 << std::vector<unsigned char>(20, i) << OP_EQUALVERIFY << OP_CHECKSIG;
            mtx.vout.emplace_back(CoinJoin::GetSmallestDenomination(), spk);
        }
        dstx.tx = MakeTransactionRef(mtx);
        dstx.m_protxHash = uint256::ONE;
        // mark as confirmed at height 100
        dstx.SetConfirmedHeight(100);
    }

    int expiry_height = 124; // 125 - 100 == 25 > 24 → expired by height

    // Minimal CBlockIndex with required fields
    // Create a minimal block index to satisfy the interface
    CBlockIndex index;
    uint256 blk_hash = uint256S("03");
    index.nHeight = expiry_height;
    index.phashBlock = &blk_hash;

    auto& man = *Assert(m_node.dstxman);
    auto& hash = dstx.tx->GetHash();
    man.AddDSTX(dstx);
    BOOST_CHECK(static_cast<bool>(man.GetDSTX(hash)));

    man.UpdatedBlockTip(&index);
    BOOST_CHECK(static_cast<bool>(man.GetDSTX(hash)));

    index.nHeight = expiry_height + 1;
    man.UpdatedBlockTip(&index);
    BOOST_CHECK(!static_cast<bool>(man.GetDSTX(hash)));
}

BOOST_AUTO_TEST_CASE(update_heights_block_connect_disconnect)
{
    CCoinJoinBroadcastTx dstx = MakeDSTX();
    auto& man = *Assert(m_node.dstxman);
    man.AddDSTX(dstx);

    // Create a fake block containing the tx
    auto block = std::make_shared<CBlock>();
    block->vtx.push_back(dstx.tx);
    CBlockIndex index;
    index.nHeight = 100;
    uint256 bh = uint256S("0b");
    index.phashBlock = &bh;

    // Height should set to 100 on connect
    man.BlockConnected(block, &index);
    {
        auto got = man.GetDSTX(dstx.tx->GetHash());
        BOOST_CHECK(static_cast<bool>(got));
        BOOST_CHECK(got.GetConfirmedHeight().has_value());
        BOOST_CHECK_EQUAL(*got.GetConfirmedHeight(), 100);
    }

    // Height should clear on disconnect
    man.BlockDisconnected(block, nullptr);
    {
        auto got = man.GetDSTX(dstx.tx->GetHash());
        BOOST_CHECK(static_cast<bool>(got));
        BOOST_CHECK(!got.GetConfirmedHeight().has_value());
    }
}

BOOST_AUTO_TEST_CASE(mempool_reentry_clears_confirmed_height)
{
    // After a block connect sets the confirmed height, the same tx being
    // (re)added to the mempool, e.g. via a reorg, should clear it. This
    // drives DSTX expiry logic that watches GetConfirmedHeight().
    CCoinJoinBroadcastTx dstx = MakeDSTX();
    auto& man = *Assert(m_node.dstxman);
    man.AddDSTX(dstx);

    auto block = std::make_shared<CBlock>();
    block->vtx.push_back(dstx.tx);
    CBlockIndex index;
    index.nHeight = 200;
    uint256 bh = uint256S("0c");
    index.phashBlock = &bh;

    man.BlockConnected(block, &index);
    {
        auto got = man.GetDSTX(dstx.tx->GetHash());
        BOOST_REQUIRE(static_cast<bool>(got));
        BOOST_REQUIRE(got.GetConfirmedHeight().has_value());
        BOOST_CHECK_EQUAL(*got.GetConfirmedHeight(), 200);
    }

    // Re-entry to the mempool clears the confirmed height (without removing the entry).
    man.TransactionAddedToMempool(dstx.tx);
    {
        auto got = man.GetDSTX(dstx.tx->GetHash());
        BOOST_REQUIRE(static_cast<bool>(got));
        BOOST_CHECK(!got.GetConfirmedHeight().has_value());
    }
}

BOOST_AUTO_TEST_CASE(mempool_event_unrelated_tx_does_not_mutate_dstx)
{
    // TransactionAddedToMempool for a transaction that is not a tracked DSTX
    // must be a no-op for any stored DSTX state.
    CCoinJoinBroadcastTx dstx = MakeDSTX();
    auto& man = *Assert(m_node.dstxman);
    man.AddDSTX(dstx);

    // Establish a confirmed height to detect any unwanted mutation.
    auto block = std::make_shared<CBlock>();
    block->vtx.push_back(dstx.tx);
    CBlockIndex index;
    index.nHeight = 321;
    uint256 bh = uint256S("0d");
    index.phashBlock = &bh;
    man.BlockConnected(block, &index);

    // Build an unrelated transaction by mutating one input of the tracked tx so it hashes differently.
    CMutableTransaction other_mtx(*dstx.tx);
    other_mtx.vin[0].prevout = COutPoint(uint256S("ee"), 7);
    auto other_tx = MakeTransactionRef(other_mtx);
    BOOST_REQUIRE(other_tx->GetHash() != dstx.tx->GetHash());

    man.TransactionAddedToMempool(other_tx);

    // Stored DSTX still has its confirmed height.
    auto got = man.GetDSTX(dstx.tx->GetHash());
    BOOST_REQUIRE(static_cast<bool>(got));
    BOOST_REQUIRE(got.GetConfirmedHeight().has_value());
    BOOST_CHECK_EQUAL(*got.GetConfirmedHeight(), 321);
    // Unrelated tx was not inserted as a DSTX.
    BOOST_CHECK(!static_cast<bool>(man.GetDSTX(other_tx->GetHash())));
}

BOOST_AUTO_TEST_SUITE_END()