diff --git a/contractcourt/chain_watcher_reorg_test.go b/contractcourt/chain_watcher_reorg_test.go new file mode 100644 index 000000000..141eda571 --- /dev/null +++ b/contractcourt/chain_watcher_reorg_test.go @@ -0,0 +1,404 @@ +package contractcourt + +import ( + "testing" + "time" + + "github.com/btcsuite/btcd/wire" + "pgregory.net/rapid" +) + +// closeType represents the type of channel close for testing purposes. +type closeType int + +const ( + // closeTypeCoop represents a cooperative channel close. + closeTypeCoop closeType = iota + + // closeTypeRemoteUnilateral represents a remote unilateral close + // (remote party broadcasting their commitment). + closeTypeRemoteUnilateral + + // closeTypeLocalForce represents a local force close (us broadcasting + // our commitment). + closeTypeLocalForce + + // closeTypeBreach represents a breach (remote party broadcasting a + // revoked commitment). + closeTypeBreach +) + +// String returns a string representation of the close type. +func (c closeType) String() string { + switch c { + case closeTypeCoop: + return "cooperative" + case closeTypeRemoteUnilateral: + return "remote_unilateral" + case closeTypeLocalForce: + return "local_force" + case closeTypeBreach: + return "breach" + default: + return "unknown" + } +} + +// createCloseTx creates a close transaction of the specified type using the +// harness. +func createCloseTx(h *chainWatcherTestHarness, ct closeType, + outputValue int64) *wire.MsgTx { + + switch ct { + case closeTypeCoop: + return h.createCoopCloseTx(outputValue) + case closeTypeRemoteUnilateral: + return h.createRemoteForceCloseTx() + case closeTypeLocalForce: + return h.createLocalForceCloseTx() + case closeTypeBreach: + return h.createBreachCloseTx() + default: + h.t.Fatalf("unknown close type: %v", ct) + return nil + } +} + +// waitForCloseEvent waits for the appropriate close event based on close type. +func waitForCloseEvent(h *chainWatcherTestHarness, ct closeType, + timeout time.Duration) any { + + switch ct { + case closeTypeCoop: + return h.waitForCoopClose(timeout) + case closeTypeRemoteUnilateral: + return h.waitForRemoteUnilateralClose(timeout) + case closeTypeLocalForce: + return h.waitForLocalUnilateralClose(timeout) + case closeTypeBreach: + return h.waitForBreach(timeout) + default: + h.t.Fatalf("unknown close type: %v", ct) + return nil + } +} + +// assertCloseEventTx asserts that the close event matches the expected +// transaction based on close type. +func assertCloseEventTx(h *chainWatcherTestHarness, ct closeType, + event any, expectedTx *wire.MsgTx) { + + switch ct { + case closeTypeCoop: + coopInfo, ok := event.(*CooperativeCloseInfo) + if !ok { + h.t.Fatalf("expected CooperativeCloseInfo, got %T", + event) + } + h.assertCoopCloseTx(coopInfo, expectedTx) + + case closeTypeRemoteUnilateral: + remoteInfo, ok := event.(*RemoteUnilateralCloseInfo) + if !ok { + h.t.Fatalf("expected RemoteUnilateralCloseInfo, got %T", + event) + } + h.assertRemoteUnilateralCloseTx(remoteInfo, expectedTx) + + case closeTypeLocalForce: + localInfo, ok := event.(*LocalUnilateralCloseInfo) + if !ok { + h.t.Fatalf("expected LocalUnilateralCloseInfo, got %T", + event) + } + h.assertLocalUnilateralCloseTx(localInfo, expectedTx) + + case closeTypeBreach: + breachInfo, ok := event.(*BreachCloseInfo) + if !ok { + h.t.Fatalf("expected BreachCloseInfo, got %T", event) + } + h.assertBreachTx(breachInfo, expectedTx) + + default: + h.t.Fatalf("unknown close type: %v", ct) + } +} + +// generateAltTxsForReorgs generates alternative transactions for reorg +// scenarios. For commitment-based closes (breach, remote/local force), the same +// tx is reused since we can only have one commitment tx per channel state. For +// coop closes, new transactions with different output values are created. +func generateAltTxsForReorgs(h *chainWatcherTestHarness, ct closeType, + originalTx *wire.MsgTx, numReorgs int, sameTxAtEnd bool) []*wire.MsgTx { + + altTxs := make([]*wire.MsgTx, numReorgs) + + for i := 0; i < numReorgs; i++ { + switch ct { + case closeTypeBreach, closeTypeRemoteUnilateral, + closeTypeLocalForce: + + // Non-coop closes can only have one commitment tx, so + // all reorgs use the same transaction. + altTxs[i] = originalTx + + case closeTypeCoop: + if i == numReorgs-1 && sameTxAtEnd { + // Last reorg goes back to original transaction. + altTxs[i] = originalTx + } else { + // Create different coop close tx with different + // output value to make it unique. + outputValue := int64(5000 - (i+1)*100) + altTxs[i] = createCloseTx(h, ct, outputValue) + } + } + } + + return altTxs +} + +// testReorgProperties is the main property-based test for reorg handling +// across all close types. +// +// The testingT parameter is captured from the outer test function and used +// for operations that require *testing.T (like channel creation), while the +// rapid.T is used for all test reporting and property generation. +func testReorgProperties(testingT *testing.T) func(*rapid.T) { + return func(t *rapid.T) { + // Generate random close type. + allCloseTypes := []closeType{ + closeTypeCoop, + closeTypeRemoteUnilateral, + closeTypeLocalForce, + closeTypeBreach, + } + ct := rapid.SampledFrom(allCloseTypes).Draw(t, "closeType") + + // Generate random number of required confirmations (2-6). We + // use at least 2 so we have room for reorgs during + // confirmation. + requiredConfs := rapid.IntRange(2, 6).Draw(t, "requiredConfs") + + // Generate number of reorgs (1-3 to keep test runtime + // reasonable). + numReorgs := rapid.IntRange(1, 3).Draw(t, "numReorgs") + + // Generate whether the final transaction is the same as the + // original. + sameTxAtEnd := rapid.Bool().Draw(t, "sameTxAtEnd") + + // Log test parameters for debugging. + t.Logf("Testing %s close with %d confs, %d reorgs, "+ + "sameTxAtEnd=%v", + ct, requiredConfs, numReorgs, sameTxAtEnd) + + // Create test harness using both the concrete *testing.T for + // channel creation and the rapid.T for test reporting. + harness := newChainWatcherTestHarnessFromReporter( + testingT, t, withRequiredConfs(uint32(requiredConfs)), + ) + + // Create initial transaction. + tx1 := createCloseTx(harness, ct, 5000) + + // Generate alternative transactions for each reorg. + altTxs := generateAltTxsForReorgs( + harness, ct, tx1, numReorgs, sameTxAtEnd, + ) + + // Send the initial spend. + harness.sendSpend(tx1) + harness.waitForConfRegistration() + + // Execute the set of re-orgs, based on our random sample, we'll + // mine N blocks, do a re-org of size N, then wait for + // detection, and repeat. + for i := 0; i < numReorgs; i++ { + // Generate random reorg depth (1 to requiredConfs-1). + // We cap it to avoid reorging too far back. + reorgDepth := rapid.IntRange( + 1, requiredConfs-1, + ).Draw(t, "reorgDepth") + + // Mine some blocks (but less than required confs). + blocksToMine := rapid.IntRange( + 1, requiredConfs-1, + ).Draw(t, "blocksToMine") + harness.mineBlocks(int32(blocksToMine)) + + // Trigger reorg. + if i == 0 { + harness.triggerReorg( + tx1, int32(reorgDepth), + ) + } else { + harness.triggerReorg( + altTxs[i-1], int32(reorgDepth), + ) + } + + harness.waitForSpendRegistration() + + harness.sendSpend(altTxs[i]) + harness.waitForConfRegistration() + } + + // Mine enough blocks to confirm final transaction. + harness.mineBlocks(1) + finalTx := altTxs[numReorgs-1] + harness.confirmTx(finalTx, harness.currentHeight) + + // Wait for and verify close event. + event := waitForCloseEvent(harness, ct, 10*time.Second) + assertCloseEventTx(harness, ct, event, finalTx) + } +} + +// TestChainWatcherReorgAllCloseTypes runs property-based tests for reorg +// handling across all channel close types. It generates random combinations of +// the following: +// - Close type (coop, remote unilateral, local force, breach) +// - Number of confirmations required (2-6) +// - Number of reorgs (1-3) +// - Whether the final tx is same as original or different. +func TestChainWatcherReorgAllCloseTypes(t *testing.T) { + t.Parallel() + + rapid.Check(t, testReorgProperties(t)) +} + +// TestRemoteUnilateralCloseWithSingleReorg tests that a remote unilateral +// close is properly handled when a single reorg occurs during confirmation. +func TestRemoteUnilateralCloseWithSingleReorg(t *testing.T) { + t.Parallel() + + harness := newChainWatcherTestHarness(t) + + // Create two remote unilateral close transactions. + // Since these are commitment transactions, we can only have one per + // state, so we'll use the current one as tx1. + tx1 := harness.createRemoteForceCloseTx() + + // Advance channel state to get a different commitment. + _ = harness.createBreachCloseTx() + tx2 := harness.createRemoteForceCloseTx() + + // Send initial spend. + harness.sendSpend(tx1) + harness.waitForConfRegistration() + + // Mine a block and trigger reorg. + harness.mineBlocks(1) + harness.triggerReorg(tx1, 1) + + // Send alternative transaction after reorg. + harness.waitForSpendRegistration() + harness.sendSpend(tx2) + harness.waitForConfRegistration() + harness.mineBlocks(1) + harness.confirmTx(tx2, harness.currentHeight) + + // Verify correct event. + closeInfo := harness.waitForRemoteUnilateralClose(5 * time.Second) + harness.assertRemoteUnilateralCloseTx(closeInfo, tx2) +} + +// TestLocalForceCloseWithMultipleReorgs tests that a local force close is +// properly handled through multiple consecutive reorgs. +func TestLocalForceCloseWithMultipleReorgs(t *testing.T) { + t.Parallel() + + harness := newChainWatcherTestHarness(t) + + // For local force close, we can only broadcast our current commitment. + // We'll simulate multiple reorgs where the same tx keeps getting + // reorganized out and re-broadcast. + tx := harness.createLocalForceCloseTx() + + // First spend and reorg. + harness.sendSpend(tx) + harness.waitForConfRegistration() + harness.mineBlocks(1) + harness.triggerReorg(tx, 1) + + // Second spend and reorg. + harness.waitForSpendRegistration() + harness.sendSpend(tx) + harness.waitForConfRegistration() + harness.mineBlocks(1) + harness.triggerReorg(tx, 1) + + // Third spend - this one confirms. + harness.waitForSpendRegistration() + harness.sendSpend(tx) + harness.waitForConfRegistration() + harness.mineBlocks(1) + harness.confirmTx(tx, harness.currentHeight) + + // Verify correct event. + closeInfo := harness.waitForLocalUnilateralClose(5 * time.Second) + harness.assertLocalUnilateralCloseTx(closeInfo, tx) +} + +// TestBreachCloseWithDeepReorg tests that a breach (revoked commitment) is +// properly detected after a deep reorganization. +func TestBreachCloseWithDeepReorg(t *testing.T) { + t.Parallel() + + harness := newChainWatcherTestHarness(t) + + // Create a revoked commitment transaction. + revokedTx := harness.createBreachCloseTx() + + // Send spend and wait for confirmation registration. + harness.sendSpend(revokedTx) + harness.waitForConfRegistration() + + // Mine several blocks and then trigger a deep reorg. + harness.mineBlocks(5) + harness.triggerReorg(revokedTx, 5) + + // Re-broadcast same transaction after reorg. + harness.waitForSpendRegistration() + harness.sendSpend(revokedTx) + harness.waitForConfRegistration() + harness.mineBlocks(1) + harness.confirmTx(revokedTx, harness.currentHeight) + + // Verify breach detection. + breachInfo := harness.waitForBreach(5 * time.Second) + harness.assertBreachTx(breachInfo, revokedTx) +} + +// TestCoopCloseReorgToForceClose tests the edge case where a cooperative +// close gets reorged out and is replaced by a force close. +func TestCoopCloseReorgToForceClose(t *testing.T) { + t.Parallel() + + harness := newChainWatcherTestHarness(t) + + // Create a cooperative close and a force close transaction. + coopTx := harness.createCoopCloseTx(5000) + forceTx := harness.createRemoteForceCloseTx() + + // Send cooperative close. + harness.sendSpend(coopTx) + harness.waitForConfRegistration() + + // Trigger reorg that removes coop close. + harness.mineBlocks(1) + harness.triggerReorg(coopTx, 1) + + // Send force close as alternative. + harness.waitForSpendRegistration() + harness.sendSpend(forceTx) + harness.waitForConfRegistration() + harness.mineBlocks(1) + harness.confirmTx(forceTx, harness.currentHeight) + + // Should receive remote unilateral close event, not coop close. + closeInfo := harness.waitForRemoteUnilateralClose(5 * time.Second) + harness.assertRemoteUnilateralCloseTx(closeInfo, forceTx) +}