tests: pull ComputeBlockVersion test into its own function

The intent here is to allow checking ComputeBlockVersion behaviour with
each deployment, rather than only testdummy on mainnet. This commit does
the trivial refactoring component of that change.

Author: ajtowns

src/test/versionbits_tests.cpp

@@ -242,17 +242,15 @@ BOOST_AUTO_TEST_CASE(versionbits_test)
     }
 }
 
-BOOST_AUTO_TEST_CASE(versionbits_computeblockversion)
+/** Check that ComputeBlockVersion will set the appropriate bit correctly */
+static void check_computeblockversion(const Consensus::Params& params, Consensus::DeploymentPos dep)
 {
-    // Check that ComputeBlockVersion will set the appropriate bit correctly
-    // on mainnet.
-    const auto chainParams = CreateChainParams(*m_node.args, CBaseChainParams::MAIN);
-    const Consensus::Params &mainnetParams = chainParams->GetConsensus();
+    // This implicitly uses versionbitscache, so clear it every time
+    versionbitscache.Clear();
 
-    // Use the TESTDUMMY deployment for testing purposes.
-    int64_t bit = mainnetParams.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].bit;
-    int64_t nStartTime = mainnetParams.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nStartTime;
-    int64_t nTimeout = mainnetParams.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nTimeout;
+    int64_t bit = params.vDeployments[dep].bit;
+    int64_t nStartTime = params.vDeployments[dep].nStartTime;
+    int64_t nTimeout = params.vDeployments[dep].nTimeout;
 
     assert(nStartTime < nTimeout);
 
@@ -267,40 +265,40 @@ BOOST_AUTO_TEST_CASE(versionbits_computeblockversion)
     // Before MedianTimePast of the chain has crossed nStartTime, the bit
     // should not be set.
     CBlockIndex *lastBlock = nullptr;
-    lastBlock = firstChain.Mine(mainnetParams.nMinerConfirmationWindow, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
-    BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, mainnetParams) & (1<<bit), 0);
+    lastBlock = firstChain.Mine(params.nMinerConfirmationWindow, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
+    BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, params) & (1<<bit), 0);
 
     // Mine more blocks (4 less than the adjustment period) at the old time, and check that CBV isn't setting the bit yet.
-    for (uint32_t i = 1; i < mainnetParams.nMinerConfirmationWindow - 4; i++) {
-        lastBlock = firstChain.Mine(mainnetParams.nMinerConfirmationWindow + i, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
+    for (uint32_t i = 1; i < params.nMinerConfirmationWindow - 4; i++) {
+        lastBlock = firstChain.Mine(params.nMinerConfirmationWindow + i, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
         // This works because VERSIONBITS_LAST_OLD_BLOCK_VERSION happens
         // to be 4, and the bit we're testing happens to be bit 28.
-        BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, mainnetParams) & (1<<bit), 0);
+        BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, params) & (1<<bit), 0);
     }
     // Now mine 5 more blocks at the start time -- MTP should not have passed yet, so
     // CBV should still not yet set the bit.
     nTime = nStartTime;
-    for (uint32_t i = mainnetParams.nMinerConfirmationWindow - 4; i <= mainnetParams.nMinerConfirmationWindow; i++) {
-        lastBlock = firstChain.Mine(mainnetParams.nMinerConfirmationWindow + i, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
-        BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, mainnetParams) & (1<<bit), 0);
+    for (uint32_t i = params.nMinerConfirmationWindow - 4; i <= params.nMinerConfirmationWindow; i++) {
+        lastBlock = firstChain.Mine(params.nMinerConfirmationWindow + i, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
+        BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, params) & (1<<bit), 0);
     }
 
     // Advance to the next period and transition to STARTED,
-    lastBlock = firstChain.Mine(mainnetParams.nMinerConfirmationWindow * 3, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
+    lastBlock = firstChain.Mine(params.nMinerConfirmationWindow * 3, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
     // so ComputeBlockVersion should now set the bit,
-    BOOST_CHECK((ComputeBlockVersion(lastBlock, mainnetParams) & (1<<bit)) != 0);
+    BOOST_CHECK((ComputeBlockVersion(lastBlock, params) & (1<<bit)) != 0);
     // and should also be using the VERSIONBITS_TOP_BITS.
-    BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, mainnetParams) & VERSIONBITS_TOP_MASK, VERSIONBITS_TOP_BITS);
+    BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, params) & VERSIONBITS_TOP_MASK, VERSIONBITS_TOP_BITS);
 
     // Check that ComputeBlockVersion will set the bit until nTimeout
     nTime += 600;
-    uint32_t blocksToMine = mainnetParams.nMinerConfirmationWindow * 2; // test blocks for up to 2 time periods
-    uint32_t nHeight = mainnetParams.nMinerConfirmationWindow * 3;
+    uint32_t blocksToMine = params.nMinerConfirmationWindow * 2; // test blocks for up to 2 time periods
+    uint32_t nHeight = params.nMinerConfirmationWindow * 3;
     // These blocks are all before nTimeout is reached.
     while (nTime < nTimeout && blocksToMine > 0) {
         lastBlock = firstChain.Mine(nHeight+1, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
-        BOOST_CHECK((ComputeBlockVersion(lastBlock, mainnetParams) & (1<<bit)) != 0);
-        BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, mainnetParams) & VERSIONBITS_TOP_MASK, VERSIONBITS_TOP_BITS);
+        BOOST_CHECK((ComputeBlockVersion(lastBlock, params) & (1<<bit)) != 0);
+        BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, params) & VERSIONBITS_TOP_MASK, VERSIONBITS_TOP_BITS);
         blocksToMine--;
         nTime += 600;
         nHeight += 1;
@@ -309,14 +307,14 @@ BOOST_AUTO_TEST_CASE(versionbits_computeblockversion)
     nTime = nTimeout;
     // FAILED is only triggered at the end of a period, so CBV should be setting
     // the bit until the period transition.
-    for (uint32_t i = 0; i < mainnetParams.nMinerConfirmationWindow - 1; i++) {
+    for (uint32_t i = 0; i < params.nMinerConfirmationWindow - 1; i++) {
         lastBlock = firstChain.Mine(nHeight+1, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
-        BOOST_CHECK((ComputeBlockVersion(lastBlock, mainnetParams) & (1<<bit)) != 0);
+        BOOST_CHECK((ComputeBlockVersion(lastBlock, params) & (1<<bit)) != 0);
         nHeight += 1;
     }
     // The next block should trigger no longer setting the bit.
     lastBlock = firstChain.Mine(nHeight+1, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
-    BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, mainnetParams) & (1<<bit), 0);
+    BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, params) & (1<<bit), 0);
 
     // On a new chain:
     // verify that the bit will be set after lock-in, and then stop being set
@@ -325,26 +323,32 @@ BOOST_AUTO_TEST_CASE(versionbits_computeblockversion)
 
     // Mine one period worth of blocks, and check that the bit will be on for the
     // next period.
-    lastBlock = secondChain.Mine(mainnetParams.nMinerConfirmationWindow, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
-    BOOST_CHECK((ComputeBlockVersion(lastBlock, mainnetParams) & (1<<bit)) != 0);
+    lastBlock = secondChain.Mine(params.nMinerConfirmationWindow, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
+    BOOST_CHECK((ComputeBlockVersion(lastBlock, params) & (1<<bit)) != 0);
 
     // Mine another period worth of blocks, signaling the new bit.
-    lastBlock = secondChain.Mine(mainnetParams.nMinerConfirmationWindow * 2, nTime, VERSIONBITS_TOP_BITS | (1<<bit)).Tip();
+    lastBlock = secondChain.Mine(params.nMinerConfirmationWindow * 2, nTime, VERSIONBITS_TOP_BITS | (1<<bit)).Tip();
     // After one period of setting the bit on each block, it should have locked in.
     // We keep setting the bit for one more period though, until activation.
-    BOOST_CHECK((ComputeBlockVersion(lastBlock, mainnetParams) & (1<<bit)) != 0);
+    BOOST_CHECK((ComputeBlockVersion(lastBlock, params) & (1<<bit)) != 0);
 
     // Now check that we keep mining the block until the end of this period, and
     // then stop at the beginning of the next period.
-    lastBlock = secondChain.Mine((mainnetParams.nMinerConfirmationWindow * 3) - 1, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
-    BOOST_CHECK((ComputeBlockVersion(lastBlock, mainnetParams) & (1 << bit)) != 0);
-    lastBlock = secondChain.Mine(mainnetParams.nMinerConfirmationWindow * 3, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
-    BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, mainnetParams) & (1<<bit), 0);
+    lastBlock = secondChain.Mine((params.nMinerConfirmationWindow * 3) - 1, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
+    BOOST_CHECK((ComputeBlockVersion(lastBlock, params) & (1 << bit)) != 0);
+    lastBlock = secondChain.Mine(params.nMinerConfirmationWindow * 3, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
+    BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, params) & (1<<bit), 0);
 
     // Finally, verify that after a soft fork has activated, CBV no longer uses
     // VERSIONBITS_LAST_OLD_BLOCK_VERSION.
     //BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, mainnetParams) & VERSIONBITS_TOP_MASK, VERSIONBITS_TOP_BITS);
 }
 
+BOOST_AUTO_TEST_CASE(versionbits_computeblockversion)
+{
+    // Use the TESTDUMMY deployment for testing purposes.
+    const auto chainParams = CreateChainParams(*m_node.args, CBaseChainParams::MAIN);
+    check_computeblockversion(chainParams->GetConsensus(), Consensus::DEPLOYMENT_TESTDUMMY);
+}
 
 BOOST_AUTO_TEST_SUITE_END()