test: add comprehensive unit tests for LLMQ subsystem

Adds unit test coverage for core LLMQ
components that were previously only covered by functional tests.

New test files:
- llmq_commitment_tests.cpp: CFinalCommitment serialization, validation
- llmq_chainlock_tests.cpp: CChainLockSig construction and serialization
- llmq_hash_tests.cpp: BuildCommitmentHash deterministic behavior
- llmq_params_tests.cpp: LLMQParams calculations for rotated/non-rotated quorums
- llmq_snapshot_tests.cpp: CQuorumSnapshot and CQuorumRotationInfo structures
- llmq_utils_tests.cpp: DeterministicOutboundConnection behavior
- llmq_test_utils.h: Common test utilities and helpers

Author: PastaPastaPasta

src/Makefile.test.include

@@ -128,6 +128,13 @@ BITCOIN_TESTS =\
   test/lcg.h \
   test/limitedmap_tests.cpp \
   test/llmq_dkg_tests.cpp \
+  test/llmq_chainlock_tests.cpp \
+  test/llmq_commitment_tests.cpp \
+  test/llmq_hash_tests.cpp \
+  test/llmq_params_tests.cpp \
+  test/llmq_snapshot_tests.cpp \
+  test/llmq_test_utils.h \
+  test/llmq_utils_tests.cpp \
   test/logging_tests.cpp \
   test/dbwrapper_tests.cpp \
   test/validation_tests.cpp \

src/test/llmq_chainlock_tests.cpp

@@ -0,0 +1,167 @@
+// Copyright (c) 2024 The Dash Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <test/llmq_test_utils.h>
+#include <test/util/setup_common.h>
+
+#include <llmq/clsig.h>
+#include <streams.h>
+
+#include <boost/test/unit_test.hpp>
+
+using namespace llmq;
+using namespace llmq::testutils;
+
+BOOST_FIXTURE_TEST_SUITE(llmq_chainlock_tests, BasicTestingSetup)
+
+BOOST_AUTO_TEST_CASE(chainlock_construction_test)
+{
+    // Test default constructor
+    CChainLockSig clsig1;
+    BOOST_CHECK(clsig1.IsNull());
+    BOOST_CHECK_EQUAL(clsig1.getHeight(), -1);
+    BOOST_CHECK(clsig1.getBlockHash().IsNull());
+    BOOST_CHECK(!clsig1.getSig().IsValid());
+
+    // Test parameterized constructor
+    int32_t height = 12345;
+    uint256 blockHash = GetTestBlockHash(1);
+    CBLSSignature sig = CreateRandomBLSSignature();
+
+    CChainLockSig clsig2(height, blockHash, sig);
+    BOOST_CHECK(!clsig2.IsNull());
+    BOOST_CHECK_EQUAL(clsig2.getHeight(), height);
+    BOOST_CHECK(clsig2.getBlockHash() == blockHash);
+    BOOST_CHECK(clsig2.getSig() == sig);
+}
+
+BOOST_AUTO_TEST_CASE(chainlock_null_test)
+{
+    CChainLockSig clsig;
+
+    // Default constructed should be null
+    BOOST_CHECK(clsig.IsNull());
+
+    // With height set but null hash, should not be null
+    clsig = CChainLockSig(100, uint256(), CBLSSignature());
+    BOOST_CHECK(!clsig.IsNull());
+
+    // With valid data should not be null
+    clsig = CreateChainLock(100, GetTestBlockHash(1));
+    BOOST_CHECK(!clsig.IsNull());
+}
+
+BOOST_AUTO_TEST_CASE(chainlock_serialization_test)
+{
+    // Test with valid chainlock
+    CChainLockSig clsig = CreateChainLock(67890, GetTestBlockHash(42));
+
+    // Test serialization preserves all fields
+    CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
+    ss << clsig;
+
+    CChainLockSig deserialized;
+    ss >> deserialized;
+
+    BOOST_CHECK_EQUAL(clsig.getHeight(), deserialized.getHeight());
+    BOOST_CHECK(clsig.getBlockHash() == deserialized.getBlockHash());
+    BOOST_CHECK(clsig.getSig() == deserialized.getSig());
+    BOOST_CHECK_EQUAL(clsig.IsNull(), deserialized.IsNull());
+}
+
+BOOST_AUTO_TEST_CASE(chainlock_tostring_test)
+{
+    // Test null chainlock
+    CChainLockSig nullClsig;
+    std::string nullStr = nullClsig.ToString();
+    BOOST_CHECK(!nullStr.empty());
+
+    // Test valid chainlock
+    int32_t height = 123456;
+    uint256 blockHash = GetTestBlockHash(789);
+    CChainLockSig clsig = CreateChainLock(height, blockHash);
+
+    std::string str = clsig.ToString();
+    BOOST_CHECK(!str.empty());
+
+    // ToString should contain height and hash info
+    BOOST_CHECK(str.find(std::to_string(height)) != std::string::npos);
+    BOOST_CHECK(str.find(blockHash.ToString().substr(0, 10)) != std::string::npos);
+}
+
+BOOST_AUTO_TEST_CASE(chainlock_edge_cases_test)
+{
+    // Test with edge case heights
+    CChainLockSig clsig1 = CreateChainLock(0, GetTestBlockHash(1));
+    BOOST_CHECK_EQUAL(clsig1.getHeight(), 0);
+    BOOST_CHECK(!clsig1.IsNull());
+
+    CChainLockSig clsig2 = CreateChainLock(std::numeric_limits<int32_t>::max(), GetTestBlockHash(2));
+    BOOST_CHECK_EQUAL(clsig2.getHeight(), std::numeric_limits<int32_t>::max());
+
+    // Test serialization with extreme values
+    CDataStream ss1(SER_NETWORK, PROTOCOL_VERSION);
+    ss1 << clsig1;
+    CChainLockSig clsig1_deserialized;
+    ss1 >> clsig1_deserialized;
+    BOOST_CHECK_EQUAL(clsig1.getHeight(), clsig1_deserialized.getHeight());
+
+    CDataStream ss2(SER_NETWORK, PROTOCOL_VERSION);
+    ss2 << clsig2;
+    CChainLockSig clsig2_deserialized;
+    ss2 >> clsig2_deserialized;
+    BOOST_CHECK_EQUAL(clsig2.getHeight(), clsig2_deserialized.getHeight());
+}
+
+BOOST_AUTO_TEST_CASE(chainlock_comparison_test)
+{
+    // Create identical chainlocks
+    int32_t height = 5000;
+    uint256 blockHash = GetTestBlockHash(10);
+    CBLSSignature sig = CreateRandomBLSSignature();
+
+    CChainLockSig clsig1(height, blockHash, sig);
+    CChainLockSig clsig2(height, blockHash, sig);
+
+    // Verify getters return same values
+    BOOST_CHECK_EQUAL(clsig1.getHeight(), clsig2.getHeight());
+    BOOST_CHECK(clsig1.getBlockHash() == clsig2.getBlockHash());
+    BOOST_CHECK(clsig1.getSig() == clsig2.getSig());
+
+    // Different chainlocks
+    CChainLockSig clsig3(height + 1, blockHash, sig);
+    BOOST_CHECK(clsig1.getHeight() != clsig3.getHeight());
+
+    CChainLockSig clsig4(height, GetTestBlockHash(11), sig);
+    BOOST_CHECK(clsig1.getBlockHash() != clsig4.getBlockHash());
+}
+
+BOOST_AUTO_TEST_CASE(chainlock_malformed_data_test)
+{
+    // Test deserialization of truncated data
+    CChainLockSig clsig = CreateChainLock(1000, GetTestBlockHash(5));
+
+    CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
+    ss << clsig;
+
+    // Truncate the stream
+    std::string data = ss.str();
+    for (size_t truncateAt = 1; truncateAt < data.size(); truncateAt += 10) {
+        CDataStream truncated(std::vector<unsigned char>(data.begin(), data.begin() + truncateAt), SER_NETWORK,
+                              PROTOCOL_VERSION);
+
+        CChainLockSig deserialized;
+        try {
+            truncated >> deserialized;
+            // If no exception, verify it's either complete or default
+            if (truncateAt < sizeof(int32_t)) {
+                BOOST_CHECK(deserialized.IsNull());
+            }
+        } catch (const std::exception&) {
+            // Expected for most truncation points
+        }
+    }
+}
+
+BOOST_AUTO_TEST_SUITE_END()