Add option to generate LCM from tests

.gitignore

@@ -8,6 +8,7 @@
 *.lib
 *.user
 *.xdr
+!test-lcm/**/*.xdr
 *.cache
 *.tlog
 *.lastbuildstate

docs/software/commands.md

@@ -201,11 +201,24 @@ Command options can only by placed after command.
       multiple times (default latest)
       * `--base-instance <N>` : run tests with instance numbers offset by N,
       used to run tests in parallel
+      * `--capture-lcm` : capture `LedgerCloseMeta` XDR from every
+      `closeLedger`/`closeLedgerOn` call during tests. Files are written
+      automatically at leaf-section boundaries (or test-case boundaries for
+      tests without sections) to `test-lcm/<TestFileBaseName>/`. Each file
+      is named after the test case and section path
+      (e.g. `test_name-section-subsection.xdr`) and contains
+      stream-framed `LedgerCloseMeta` entries that can be decoded with
+      `stellar-xdr decode --type LedgerCloseMeta --input stream-framed`.
+      Meta is normalized (sorted) before writing so that output is
+      deterministic given a fixed `--rng-seed`.
+  * The network passphrase is set to `(V) (;,,;) (V)` for all captured meta.
   * For [further info](https://github.com/philsquared/Catch/blob/master/docs/command-line.md)
     on possible options for test.
   * For example this will run just the tests tagged with `[tx]` using protocol
     versions 9 and 10 and stop after the first failure:
     `stellar-core test -a --version 9 --version 10 "[tx]"`
+  * To capture LCM for tests with a fixed seed:
+    `stellar-core test --capture-lcm --rng-seed 12345 "[soroban]"`
 * **upgrade-db**: Upgrades local database to current schema version. This is
   usually done automatically during stellar-core run or other command.
 * **verify-checkpoints**: Listens to the network until it observes a consensus

src/ledger/LedgerManagerImpl.cpp

@@ -1742,6 +1742,16 @@ LedgerManagerImpl::applyLedger(LedgerCloseData const& ledgerData,
         throw std::runtime_error("Local node's ledger corrupted during close");
     }
 
+#ifdef BUILD_TESTS
+    if (ledgerCloseMeta)
+    {
+        ledgerCloseMeta->ledgerHeader() =
+            appliedLedgerState->getLastClosedLedgerHeader();
+        // Copy this before we move it into mNextMetaToEmit below
+        mLastLedgerCloseMeta = *ledgerCloseMeta;
+    }
+#endif
+
     if (mMetaStream || mMetaDebugStream)
     {
         releaseAssert(ledgerCloseMeta);
@@ -2604,11 +2614,6 @@ LedgerManagerImpl::applyTransactions(
         mApplyState.getMetrics().mStagesPerLedger.set_count(applyStages.size());
     }
 
-#ifdef BUILD_TESTS
-    releaseAssert(ledgerCloseMeta);
-    mLastLedgerCloseMeta = *ledgerCloseMeta;
-#endif
-
     logTxApplyMetrics(ltx, numTxs, numOps);
     return txResultSet;
 }

src/ledger/test/LedgerCloseMetaStreamTests.cpp

@@ -357,7 +357,8 @@ TEST_CASE_VERSIONS("meta stream contains reasonable meta", "[ledgerclosemeta]")
             // Close ledgers until out contract expires. These ledgers won't
             // emit meta
             for (uint32_t i =
-                     test.getApp().getLedgerManager().getLastClosedLedgerNum();
+                     test.getApp().getLedgerManager().getLastClosedLedgerNum() +
+                     1;
                  i <= liveUntilLedger + 1; ++i)
             {
                 closeLedgerOn(test.getApp(), i, 2, 1, 2016);

src/test/TestUtils.cpp

@@ -417,6 +417,8 @@ modifySorobanNetworkConfig(Application& app,
                                      {upgrade});
     app.getRoot()->loadSequenceNumber();
 
+    txtest::captureLastClosedLedgerLcm(app);
+
     // Check that the upgrade was actually applied.
     auto postUpgradeCfg =
         app.getLedgerManager().getLastClosedSorobanNetworkConfig();

src/test/TxTests.cpp

@@ -8,6 +8,7 @@
 #include "database/Database.h"
 #include "herder/Herder.h"
 #include "invariant/InvariantManager.h"
+#include "ledger/LedgerCloseMetaFrame.h"
 #include "ledger/LedgerTxn.h"
 #include "ledger/LedgerTxnEntry.h"
 #include "ledger/LedgerTxnHeader.h"
@@ -24,10 +25,12 @@
 #include "transactions/TransactionBridge.h"
 #include "transactions/TransactionFrame.h"
 #include "transactions/TransactionUtils.h"
+#include "util/Fs.h"
 #include "util/GlobalChecks.h"
 #include "util/Logging.h"
 #include "util/ProtocolVersion.h"
 #include "util/XDROperators.h"
+#include "util/XDRStream.h"
 #include "util/types.h"
 #include "xdrpp/autocheck.h"
 
@@ -43,6 +46,44 @@ namespace stellar
 namespace txtest
 {
 
+static std::vector<LedgerCloseMeta> gAccumulatedLcm;
+
+std::vector<LedgerCloseMeta> const&
+getAccumulatedLcm()
+{
+    return gAccumulatedLcm;
+}
+
+void
+clearAccumulatedLcm()
+{
+    gAccumulatedLcm.clear();
+}
+
+void
+appendToAccumulatedLcm(LedgerCloseMeta const& lcm)
+{
+    gAccumulatedLcm.emplace_back(lcm);
+}
+
+void
+captureLastClosedLedgerLcm(Application& app)
+{
+    // TODO: In-memory mode uses applyCheck which closes an empty ledger
+    // then applies the tx directly, so txs never appear in LCM. Fix this
+    // by restructuring applyCheck to use closeLedger(app, {tx}) when
+    // capturing LCM.
+    if (isLcmCaptureEnabled() && !app.getConfig().MODE_USES_IN_MEMORY_LEDGER)
+    {
+        auto const& closeMeta =
+            app.getLedgerManager().getLastClosedLedgerCloseMeta();
+        if (closeMeta.has_value())
+        {
+            appendToAccumulatedLcm(closeMeta->getXDR());
+        }
+    }
+}
+
 ExpectedOpResult::ExpectedOpResult(OperationResultCode code)
 {
     mOperationResult.code(code);
@@ -546,6 +587,9 @@ closeLedgerOn(Application& app, uint32 ledgerSeq, TimePoint closeTime,
     // Ensure that parallelSorobanOrder is only used with strictOrder
     releaseAssert((parallelSorobanOrder.empty() || strictOrder));
 
+    // Ensure we're not trying to close a ledger that's already closed
+    releaseAssert(ledgerSeq > app.getLedgerManager().getLastClosedLedgerNum());
+
     auto lastCloseTime = app.getLedgerManager()
                              .getLastClosedLedgerHeader()
                              .header.scpValue.closeTime;
@@ -600,6 +644,7 @@ closeLedgerOn(Application& app, uint32 ledgerSeq, TimePoint closeTime,
     }
     releaseAssert(app.getLedgerManager().getLastClosedLedgerNum() == ledgerSeq);
     auto& lm = static_cast<LedgerManagerImpl&>(app.getLedgerManager());
+    captureLastClosedLedgerLcm(app);
     return lm.mLatestTxResultSet;
 }
 
@@ -625,6 +670,8 @@ closeLedgerOn(Application& app, uint32 ledgerSeq, time_t closeTime,
 
     REQUIRE(app.getLedgerManager().getLastClosedLedgerNum() == ledgerSeq);
 
+    captureLastClosedLedgerLcm(app);
+
     return z1;
 }
 
@@ -1938,6 +1985,9 @@ executeUpgrades(Application& app, xdr::xvector<UpgradeType, 6> const& upgrades,
     auto lastCloseTime = lcl.header.scpValue.closeTime;
     app.getHerder().externalizeValue(txSet, lcl.header.ledgerSeq + 1,
                                      lastCloseTime, upgrades);
+
+    captureLastClosedLedgerLcm(app);
+
     if (upgradesIgnored)
     {
         auto const& newHeader = lm.getLastClosedLedgerHeader().header;

src/test/TxTests.h

@@ -380,5 +380,14 @@ bool isSuccessResult(TransactionResult const& res);
 
 TestAccount getGenesisAccount(Application& app, uint32_t accountIndex);
 
+// Accumulated LedgerCloseMeta from closeLedger/closeLedgerOn calls.
+// Only accumulates when --capture-lcm is passed on the test command line.
+// Note: LCM capture does not cover BucketTestUtils::closeLedger or direct
+// externalizeValue calls (e.g. genesis ledger from app->start()).
+std::vector<LedgerCloseMeta> const& getAccumulatedLcm();
+void clearAccumulatedLcm();
+void appendToAccumulatedLcm(LedgerCloseMeta const& lcm);
+void captureLastClosedLedgerLcm(Application& app);
+
 } // end txtest namespace
 }