From ba26169f6035c238378a3c9647213328a006fa23 Mon Sep 17 00:00:00 2001
From: glozow <gloriajzhao@gmail.com>
Date: Fri, 16 Jul 2021 15:08:33 +0100
Subject: [PATCH] [unit test] context-free package checks

---
 src/test/txpackage_tests.cpp | 93 ++++++++++++++++++++++++++++++++++++
 1 file changed, 93 insertions(+)

diff --git a/src/test/txpackage_tests.cpp b/src/test/txpackage_tests.cpp
index 537a6ccea1..6c996c2630 100644
--- a/src/test/txpackage_tests.cpp
+++ b/src/test/txpackage_tests.cpp
@@ -114,4 +114,97 @@ BOOST_FIXTURE_TEST_CASE(package_validation_tests, TestChain100Setup)
     // Check that mempool size hasn't changed.
     BOOST_CHECK_EQUAL(m_node.mempool->size(), initialPoolSize);
 }
+
+BOOST_FIXTURE_TEST_CASE(noncontextual_package_tests, TestChain100Setup)
+{
+    // The signatures won't be verified so we can just use a placeholder
+    CKey placeholder_key;
+    placeholder_key.MakeNewKey(true);
+    CScript spk = GetScriptForDestination(PKHash(placeholder_key.GetPubKey()));
+    CKey placeholder_key_2;
+    placeholder_key_2.MakeNewKey(true);
+    CScript spk2 = GetScriptForDestination(PKHash(placeholder_key_2.GetPubKey()));
+
+    // Parent and Child Package
+    {
+        auto mtx_parent = CreateValidMempoolTransaction(m_coinbase_txns[0], 0, 0, coinbaseKey, spk,
+                                                        CAmount(49 * COIN), /* submit */ false);
+        CTransactionRef tx_parent = MakeTransactionRef(mtx_parent);
+
+        auto mtx_child = CreateValidMempoolTransaction(tx_parent, 0, 101, placeholder_key, spk2,
+                                                       CAmount(48 * COIN), /* submit */ false);
+        CTransactionRef tx_child = MakeTransactionRef(mtx_child);
+
+        PackageValidationState state;
+        BOOST_CHECK(CheckPackage({tx_parent, tx_child}, state));
+        BOOST_CHECK(!CheckPackage({tx_child, tx_parent}, state));
+        BOOST_CHECK_EQUAL(state.GetResult(), PackageValidationResult::PCKG_POLICY);
+        BOOST_CHECK_EQUAL(state.GetRejectReason(), "package-not-sorted");
+        BOOST_CHECK(IsChildWithParents({tx_parent, tx_child}));
+    }
+
+    // 24 Parents and 1 Child
+    {
+        Package package;
+        CMutableTransaction child;
+        for (int i{0}; i < 24; ++i) {
+            auto parent = MakeTransactionRef(CreateValidMempoolTransaction(m_coinbase_txns[i + 1],
+                                             0, 0, coinbaseKey, spk, CAmount(48 * COIN), false));
+            package.emplace_back(parent);
+            child.vin.push_back(CTxIn(COutPoint(parent->GetHash(), 0)));
+        }
+        child.vout.push_back(CTxOut(47 * COIN, spk2));
+
+        // The child must be in the package.
+        BOOST_CHECK(!IsChildWithParents(package));
+
+        // The parents can be in any order.
+        FastRandomContext rng;
+        Shuffle(package.begin(), package.end(), rng);
+        package.push_back(MakeTransactionRef(child));
+
+        PackageValidationState state;
+        BOOST_CHECK(CheckPackage(package, state));
+        BOOST_CHECK(IsChildWithParents(package));
+
+        package.erase(package.begin());
+        BOOST_CHECK(IsChildWithParents(package));
+
+        // The package cannot have unrelated transactions.
+        package.insert(package.begin(), m_coinbase_txns[0]);
+        BOOST_CHECK(!IsChildWithParents(package));
+    }
+
+    // 2 Parents and 1 Child where one parent depends on the other.
+    {
+        CMutableTransaction mtx_parent;
+        mtx_parent.vin.push_back(CTxIn(COutPoint(m_coinbase_txns[0]->GetHash(), 0)));
+        mtx_parent.vout.push_back(CTxOut(20 * COIN, spk));
+        mtx_parent.vout.push_back(CTxOut(20 * COIN, spk2));
+        CTransactionRef tx_parent = MakeTransactionRef(mtx_parent);
+
+        CMutableTransaction mtx_parent_also_child;
+        mtx_parent_also_child.vin.push_back(CTxIn(COutPoint(tx_parent->GetHash(), 0)));
+        mtx_parent_also_child.vout.push_back(CTxOut(20 * COIN, spk));
+        CTransactionRef tx_parent_also_child = MakeTransactionRef(mtx_parent_also_child);
+
+        CMutableTransaction mtx_child;
+        mtx_child.vin.push_back(CTxIn(COutPoint(tx_parent->GetHash(), 1)));
+        mtx_child.vin.push_back(CTxIn(COutPoint(tx_parent_also_child->GetHash(), 0)));
+        mtx_child.vout.push_back(CTxOut(39 * COIN, spk));
+        CTransactionRef tx_child = MakeTransactionRef(mtx_child);
+
+        PackageValidationState state;
+        BOOST_CHECK(IsChildWithParents({tx_parent, tx_parent_also_child}));
+        BOOST_CHECK(IsChildWithParents({tx_parent, tx_child}));
+        BOOST_CHECK(IsChildWithParents({tx_parent, tx_parent_also_child, tx_child}));
+        // IsChildWithParents does not detect unsorted parents.
+        BOOST_CHECK(IsChildWithParents({tx_parent_also_child, tx_parent, tx_child}));
+        BOOST_CHECK(CheckPackage({tx_parent, tx_parent_also_child, tx_child}, state));
+        BOOST_CHECK(!CheckPackage({tx_parent_also_child, tx_parent, tx_child}, state));
+        BOOST_CHECK_EQUAL(state.GetResult(), PackageValidationResult::PCKG_POLICY);
+        BOOST_CHECK_EQUAL(state.GetRejectReason(), "package-not-sorted");
+    }
+}
+
 BOOST_AUTO_TEST_SUITE_END()