package sweep import ( "os" "runtime/debug" "runtime/pprof" "testing" "time" "github.com/btcsuite/btcd/btcec" "github.com/btcsuite/btcd/chaincfg/chainhash" "github.com/btcsuite/btcd/wire" "github.com/btcsuite/btcutil" "github.com/lightningnetwork/lnd/build" "github.com/lightningnetwork/lnd/input" "github.com/lightningnetwork/lnd/keychain" "github.com/lightningnetwork/lnd/lntest/mock" "github.com/lightningnetwork/lnd/lnwallet" "github.com/lightningnetwork/lnd/lnwallet/chainfee" "github.com/stretchr/testify/require" ) var ( testLog = build.NewSubLogger("SWPR_TEST", nil) testMaxSweepAttempts = 3 testMaxInputsPerTx = 3 defaultFeePref = Params{Fee: FeePreference{ConfTarget: 1}} ) type sweeperTestContext struct { t *testing.T sweeper *UtxoSweeper notifier *MockNotifier estimator *mockFeeEstimator backend *mockBackend store *MockSweeperStore timeoutChan chan chan time.Time publishChan chan wire.MsgTx } var ( spendableInputs []*input.BaseInput testInputCount int testPubKey, _ = btcec.ParsePubKey([]byte{ 0x04, 0x11, 0xdb, 0x93, 0xe1, 0xdc, 0xdb, 0x8a, 0x01, 0x6b, 0x49, 0x84, 0x0f, 0x8c, 0x53, 0xbc, 0x1e, 0xb6, 0x8a, 0x38, 0x2e, 0x97, 0xb1, 0x48, 0x2e, 0xca, 0xd7, 0xb1, 0x48, 0xa6, 0x90, 0x9a, 0x5c, 0xb2, 0xe0, 0xea, 0xdd, 0xfb, 0x84, 0xcc, 0xf9, 0x74, 0x44, 0x64, 0xf8, 0x2e, 0x16, 0x0b, 0xfa, 0x9b, 0x8b, 0x64, 0xf9, 0xd4, 0xc0, 0x3f, 0x99, 0x9b, 0x86, 0x43, 0xf6, 0x56, 0xb4, 0x12, 0xa3, }, btcec.S256()) ) func createTestInput(value int64, witnessType input.WitnessType) input.BaseInput { hash := chainhash.Hash{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, byte(testInputCount)} input := input.MakeBaseInput( &wire.OutPoint{ Hash: hash, }, witnessType, &input.SignDescriptor{ Output: &wire.TxOut{ Value: value, }, KeyDesc: keychain.KeyDescriptor{ PubKey: testPubKey, }, }, 0, nil, ) testInputCount++ return input } func init() { // Create a set of test spendable inputs. for i := 0; i < 5; i++ { input := createTestInput(int64(10000+i*500), input.CommitmentTimeLock) spendableInputs = append(spendableInputs, &input) } } func createSweeperTestContext(t *testing.T) *sweeperTestContext { notifier := NewMockNotifier(t) store := NewMockSweeperStore() backend := newMockBackend(t, notifier) backend.walletUtxos = []*lnwallet.Utxo{ { Value: btcutil.Amount(10000), AddressType: lnwallet.WitnessPubKey, }, } estimator := newMockFeeEstimator(10000, chainfee.FeePerKwFloor) ctx := &sweeperTestContext{ notifier: notifier, publishChan: backend.publishChan, t: t, estimator: estimator, backend: backend, store: store, timeoutChan: make(chan chan time.Time, 1), } var outputScriptCount byte ctx.sweeper = New(&UtxoSweeperConfig{ Notifier: notifier, Wallet: backend, NewBatchTimer: func() <-chan time.Time { c := make(chan time.Time, 1) ctx.timeoutChan <- c return c }, Store: store, Signer: &mock.DummySigner{}, GenSweepScript: func() ([]byte, error) { script := []byte{outputScriptCount} outputScriptCount++ return script, nil }, FeeEstimator: estimator, MaxInputsPerTx: testMaxInputsPerTx, MaxSweepAttempts: testMaxSweepAttempts, NextAttemptDeltaFunc: func(attempts int) int32 { // Use delta func without random factor. return 1 << uint(attempts-1) }, MaxFeeRate: DefaultMaxFeeRate, FeeRateBucketSize: DefaultFeeRateBucketSize, }) ctx.sweeper.Start() return ctx } func (ctx *sweeperTestContext) restartSweeper() { ctx.t.Helper() ctx.sweeper.Stop() ctx.sweeper = New(ctx.sweeper.cfg) ctx.sweeper.Start() } func (ctx *sweeperTestContext) tick() { testLog.Trace("Waiting for tick to be consumed") select { case c := <-ctx.timeoutChan: select { case c <- time.Time{}: testLog.Trace("Tick") case <-time.After(defaultTestTimeout): debug.PrintStack() ctx.t.Fatal("tick timeout - tick not consumed") } case <-time.After(defaultTestTimeout): debug.PrintStack() ctx.t.Fatal("tick timeout - no new timer created") } } // assertNoTick asserts that the sweeper does not wait for a tick. func (ctx *sweeperTestContext) assertNoTick() { ctx.t.Helper() select { case <-ctx.timeoutChan: ctx.t.Fatal("unexpected tick") case <-time.After(processingDelay): } } func (ctx *sweeperTestContext) assertNoNewTimer() { select { case <-ctx.timeoutChan: ctx.t.Fatal("no new timer expected") default: } } func (ctx *sweeperTestContext) finish(expectedGoroutineCount int) { // We assume that when finish is called, sweeper has finished all its // goroutines. This implies that the waitgroup is empty. signalChan := make(chan struct{}) go func() { ctx.sweeper.wg.Wait() close(signalChan) }() // Simulate exits of the expected number of running goroutines. for i := 0; i < expectedGoroutineCount; i++ { ctx.sweeper.wg.Done() } // We now expect the Wait to succeed. select { case <-signalChan: case <-time.After(time.Second): pprof.Lookup("goroutine").WriteTo(os.Stdout, 1) ctx.t.Fatalf("lingering goroutines detected after test " + "is finished") } // Restore waitgroup state to what it was before. ctx.sweeper.wg.Add(expectedGoroutineCount) // Stop sweeper. ctx.sweeper.Stop() // We should have consumed and asserted all published transactions in // our unit tests. ctx.assertNoTx() ctx.assertNoNewTimer() if !ctx.backend.isDone() { ctx.t.Fatal("unconfirmed txes remaining") } } func (ctx *sweeperTestContext) assertNoTx() { ctx.t.Helper() select { case <-ctx.publishChan: ctx.t.Fatalf("unexpected transactions published") default: } } func (ctx *sweeperTestContext) receiveTx() wire.MsgTx { ctx.t.Helper() var tx wire.MsgTx select { case tx = <-ctx.publishChan: return tx case <-time.After(5 * time.Second): pprof.Lookup("goroutine").WriteTo(os.Stdout, 1) ctx.t.Fatalf("tx not published") } return tx } func (ctx *sweeperTestContext) expectResult(c chan Result, expected error) { ctx.t.Helper() select { case result := <-c: if result.Err != expected { ctx.t.Fatalf("expected %v result, but got %v", expected, result.Err, ) } case <-time.After(defaultTestTimeout): ctx.t.Fatalf("no result received") } } func (ctx *sweeperTestContext) assertPendingInputs(inputs ...input.Input) { ctx.t.Helper() inputSet := make(map[wire.OutPoint]struct{}, len(inputs)) for _, input := range inputs { inputSet[*input.OutPoint()] = struct{}{} } pendingInputs, err := ctx.sweeper.PendingInputs() if err != nil { ctx.t.Fatal(err) } if len(pendingInputs) != len(inputSet) { ctx.t.Fatalf("expected %d pending inputs, got %d", len(inputSet), len(pendingInputs)) } for input := range pendingInputs { if _, ok := inputSet[input]; !ok { ctx.t.Fatalf("found unexpected input %v", input) } } } // assertTxSweepsInputs ensures that the transaction returned within the value // received from resultChan spends the given inputs. func assertTxSweepsInputs(t *testing.T, sweepTx *wire.MsgTx, inputs ...input.Input) { t.Helper() if len(sweepTx.TxIn) != len(inputs) { t.Fatalf("expected sweep tx to contain %d inputs, got %d", len(inputs), len(sweepTx.TxIn)) } m := make(map[wire.OutPoint]struct{}, len(inputs)) for _, input := range inputs { m[*input.OutPoint()] = struct{}{} } for _, txIn := range sweepTx.TxIn { if _, ok := m[txIn.PreviousOutPoint]; !ok { t.Fatalf("expected tx %v to spend input %v", txIn.PreviousOutPoint, sweepTx.TxHash()) } } } // assertTxFeeRate asserts that the transaction was created with the given // inputs and fee rate. // // NOTE: This assumes that transactions only have one output, as this is the // only type of transaction the UtxoSweeper can create at the moment. func assertTxFeeRate(t *testing.T, tx *wire.MsgTx, expectedFeeRate chainfee.SatPerKWeight, inputs ...input.Input) { t.Helper() if len(tx.TxIn) != len(inputs) { t.Fatalf("expected %d inputs, got %d", len(tx.TxIn), len(inputs)) } m := make(map[wire.OutPoint]input.Input, len(inputs)) for _, input := range inputs { m[*input.OutPoint()] = input } var inputAmt int64 for _, txIn := range tx.TxIn { input, ok := m[txIn.PreviousOutPoint] if !ok { t.Fatalf("expected input %v to be provided", txIn.PreviousOutPoint) } inputAmt += input.SignDesc().Output.Value } outputAmt := tx.TxOut[0].Value fee := btcutil.Amount(inputAmt - outputAmt) _, estimator := getWeightEstimate(inputs, 0) txWeight := estimator.weight() expectedFee := expectedFeeRate.FeeForWeight(int64(txWeight)) if fee != expectedFee { t.Fatalf("expected fee rate %v results in %v fee, got %v fee", expectedFeeRate, expectedFee, fee) } } // TestSuccess tests the sweeper happy flow. func TestSuccess(t *testing.T) { ctx := createSweeperTestContext(t) // Sweeping an input without a fee preference should result in an error. _, err := ctx.sweeper.SweepInput(spendableInputs[0], Params{}) if err != ErrNoFeePreference { t.Fatalf("expected ErrNoFeePreference, got %v", err) } resultChan, err := ctx.sweeper.SweepInput( spendableInputs[0], defaultFeePref, ) if err != nil { t.Fatal(err) } ctx.tick() sweepTx := ctx.receiveTx() ctx.backend.mine() select { case result := <-resultChan: if result.Err != nil { t.Fatalf("expected successful spend, but received "+ "error %v instead", result.Err) } if result.Tx.TxHash() != sweepTx.TxHash() { t.Fatalf("expected sweep tx ") } case <-time.After(5 * time.Second): t.Fatalf("no result received") } ctx.finish(1) // Assert that last tx is stored in the database so we can republish // on restart. lastTx, err := ctx.store.GetLastPublishedTx() if err != nil { t.Fatal(err) } if lastTx == nil || sweepTx.TxHash() != lastTx.TxHash() { t.Fatalf("last tx not stored") } } // TestDust asserts that inputs that are not big enough to raise above the dust // limit, are held back until the total set does surpass the limit. func TestDust(t *testing.T) { ctx := createSweeperTestContext(t) // Sweeping a single output produces a tx of 486 weight units. With the // test fee rate, the sweep tx will pay 4860 sat in fees. // // Create an input so that the output after paying fees is still // positive (400 sat), but less than the dust limit (537 sat) for the // sweep tx output script (P2WPKH). dustInput := createTestInput(5260, input.CommitmentTimeLock) _, err := ctx.sweeper.SweepInput(&dustInput, defaultFeePref) if err != nil { t.Fatal(err) } // No sweep transaction is expected now. The sweeper should recognize // that the sweep output will not be relayed and not generate the tx. It // isn't possible to attach a wallet utxo either, because the added // weight would create a negatively yielding transaction at this fee // rate. // Sweep another input that brings the tx output above the dust limit. largeInput := createTestInput(100000, input.CommitmentTimeLock) _, err = ctx.sweeper.SweepInput(&largeInput, defaultFeePref) if err != nil { t.Fatal(err) } ctx.tick() // The second input brings the sweep output above the dust limit. We // expect a sweep tx now. sweepTx := ctx.receiveTx() if len(sweepTx.TxIn) != 2 { t.Fatalf("Expected tx to sweep 2 inputs, but contains %v "+ "inputs instead", len(sweepTx.TxIn)) } ctx.backend.mine() ctx.finish(1) } // TestWalletUtxo asserts that inputs that are not big enough to raise above the // dust limit are accompanied by a wallet utxo to make them sweepable. func TestWalletUtxo(t *testing.T) { ctx := createSweeperTestContext(t) // Sweeping a single output produces a tx of 439 weight units. At the // fee floor, the sweep tx will pay 439*253/1000 = 111 sat in fees. // // Create an input so that the output after paying fees is still // positive (183 sat), but less than the dust limit (537 sat) for the // sweep tx output script (P2WPKH). // // What we now expect is that the sweeper will attach a utxo from the // wallet. This increases the tx weight to 712 units with a fee of 180 // sats. The tx yield becomes then 294-180 = 114 sats. dustInput := createTestInput(294, input.WitnessKeyHash) _, err := ctx.sweeper.SweepInput( &dustInput, Params{Fee: FeePreference{FeeRate: chainfee.FeePerKwFloor}}, ) if err != nil { t.Fatal(err) } ctx.tick() sweepTx := ctx.receiveTx() if len(sweepTx.TxIn) != 2 { t.Fatalf("Expected tx to sweep 2 inputs, but contains %v "+ "inputs instead", len(sweepTx.TxIn)) } // Calculate expected output value based on wallet utxo of 10000 sats. expectedOutputValue := int64(294 + 10000 - 180) if sweepTx.TxOut[0].Value != expectedOutputValue { t.Fatalf("Expected output value of %v, but got %v", expectedOutputValue, sweepTx.TxOut[0].Value) } ctx.backend.mine() ctx.finish(1) } // TestNegativeInput asserts that no inputs with a negative yield are swept. // Negative yield means that the value minus the added fee is negative. func TestNegativeInput(t *testing.T) { ctx := createSweeperTestContext(t) // Sweep an input large enough to cover fees, so in any case the tx // output will be above the dust limit. largeInput := createTestInput(100000, input.CommitmentNoDelay) largeInputResult, err := ctx.sweeper.SweepInput( &largeInput, defaultFeePref, ) if err != nil { t.Fatal(err) } // Sweep an additional input with a negative net yield. The weight of // the HtlcAcceptedRemoteSuccess input type adds more in fees than its // value at the current fee level. negInput := createTestInput(2900, input.HtlcOfferedRemoteTimeout) negInputResult, err := ctx.sweeper.SweepInput(&negInput, defaultFeePref) if err != nil { t.Fatal(err) } // Sweep a third input that has a smaller output than the previous one, // but yields positively because of its lower weight. positiveInput := createTestInput(2800, input.CommitmentNoDelay) positiveInputResult, err := ctx.sweeper.SweepInput( &positiveInput, defaultFeePref, ) if err != nil { t.Fatal(err) } ctx.tick() // We expect that a sweep tx is published now, but it should only // contain the large input. The negative input should stay out of sweeps // until fees come down to get a positive net yield. sweepTx1 := ctx.receiveTx() assertTxSweepsInputs(t, &sweepTx1, &largeInput, &positiveInput) ctx.backend.mine() ctx.expectResult(largeInputResult, nil) ctx.expectResult(positiveInputResult, nil) // Lower fee rate so that the negative input is no longer negative. ctx.estimator.updateFees(1000, 1000) // Create another large input. secondLargeInput := createTestInput(100000, input.CommitmentNoDelay) secondLargeInputResult, err := ctx.sweeper.SweepInput( &secondLargeInput, defaultFeePref, ) if err != nil { t.Fatal(err) } ctx.tick() sweepTx2 := ctx.receiveTx() assertTxSweepsInputs(t, &sweepTx2, &secondLargeInput, &negInput) ctx.backend.mine() ctx.expectResult(secondLargeInputResult, nil) ctx.expectResult(negInputResult, nil) ctx.finish(1) } // TestChunks asserts that large sets of inputs are split into multiple txes. func TestChunks(t *testing.T) { ctx := createSweeperTestContext(t) // Sweep five inputs. for _, input := range spendableInputs[:5] { _, err := ctx.sweeper.SweepInput(input, defaultFeePref) if err != nil { t.Fatal(err) } } ctx.tick() // We expect two txes to be published because of the max input count of // three. sweepTx1 := ctx.receiveTx() if len(sweepTx1.TxIn) != 3 { t.Fatalf("Expected first tx to sweep 3 inputs, but contains %v "+ "inputs instead", len(sweepTx1.TxIn)) } sweepTx2 := ctx.receiveTx() if len(sweepTx2.TxIn) != 2 { t.Fatalf("Expected first tx to sweep 2 inputs, but contains %v "+ "inputs instead", len(sweepTx1.TxIn)) } ctx.backend.mine() ctx.finish(1) } // TestRemoteSpend asserts that remote spends are properly detected and handled // both before the sweep is published as well as after. func TestRemoteSpend(t *testing.T) { t.Run("pre-sweep", func(t *testing.T) { testRemoteSpend(t, false) }) t.Run("post-sweep", func(t *testing.T) { testRemoteSpend(t, true) }) } func testRemoteSpend(t *testing.T, postSweep bool) { ctx := createSweeperTestContext(t) resultChan1, err := ctx.sweeper.SweepInput( spendableInputs[0], defaultFeePref, ) if err != nil { t.Fatal(err) } resultChan2, err := ctx.sweeper.SweepInput( spendableInputs[1], defaultFeePref, ) if err != nil { t.Fatal(err) } // Spend the input with an unknown tx. remoteTx := &wire.MsgTx{ TxIn: []*wire.TxIn{ { PreviousOutPoint: *(spendableInputs[0].OutPoint()), }, }, } err = ctx.backend.publishTransaction(remoteTx) if err != nil { t.Fatal(err) } if postSweep { ctx.tick() // Tx publication by sweeper returns ErrDoubleSpend. Sweeper // will retry the inputs without reporting a result. It could be // spent by the remote party. ctx.receiveTx() } ctx.backend.mine() select { case result := <-resultChan1: if result.Err != ErrRemoteSpend { t.Fatalf("expected remote spend") } if result.Tx.TxHash() != remoteTx.TxHash() { t.Fatalf("expected remote spend tx") } case <-time.After(5 * time.Second): t.Fatalf("no result received") } if !postSweep { // Assert that the sweeper sweeps the remaining input. ctx.tick() sweepTx := ctx.receiveTx() if len(sweepTx.TxIn) != 1 { t.Fatal("expected sweep to only sweep the one remaining output") } ctx.backend.mine() ctx.expectResult(resultChan2, nil) ctx.finish(1) } else { // Expected sweeper to be still listening for spend of the // error input. ctx.finish(2) select { case <-resultChan2: t.Fatalf("no result expected for error input") default: } } } // TestIdempotency asserts that offering the same input multiple times is // handled correctly. func TestIdempotency(t *testing.T) { ctx := createSweeperTestContext(t) input := spendableInputs[0] resultChan1, err := ctx.sweeper.SweepInput(input, defaultFeePref) if err != nil { t.Fatal(err) } resultChan2, err := ctx.sweeper.SweepInput(input, defaultFeePref) if err != nil { t.Fatal(err) } ctx.tick() ctx.receiveTx() resultChan3, err := ctx.sweeper.SweepInput(input, defaultFeePref) if err != nil { t.Fatal(err) } // Spend the input of the sweep tx. ctx.backend.mine() ctx.expectResult(resultChan1, nil) ctx.expectResult(resultChan2, nil) ctx.expectResult(resultChan3, nil) // Offer the same input again. The sweeper will register a spend ntfn // for this input. Because the input has already been spent, it will // immediately receive the spend notification with a spending tx hash. // Because the sweeper kept track of all of its sweep txes, it will // recognize the spend as its own. resultChan4, err := ctx.sweeper.SweepInput(input, defaultFeePref) if err != nil { t.Fatal(err) } ctx.expectResult(resultChan4, nil) // Timer is still running, but spend notification was delivered before // it expired. ctx.tick() ctx.finish(1) } // TestNoInputs asserts that nothing happens if nothing happens. func TestNoInputs(t *testing.T) { ctx := createSweeperTestContext(t) // No tx should appear. This is asserted in finish(). ctx.finish(1) } // TestRestart asserts that the sweeper picks up sweeping properly after // a restart. func TestRestart(t *testing.T) { ctx := createSweeperTestContext(t) // Sweep input and expect sweep tx. input1 := spendableInputs[0] if _, err := ctx.sweeper.SweepInput(input1, defaultFeePref); err != nil { t.Fatal(err) } ctx.tick() ctx.receiveTx() // Restart sweeper. ctx.restartSweeper() // Expect last tx to be republished. ctx.receiveTx() // Simulate other subsystem (e.g. contract resolver) re-offering inputs. spendChan1, err := ctx.sweeper.SweepInput(input1, defaultFeePref) if err != nil { t.Fatal(err) } input2 := spendableInputs[1] spendChan2, err := ctx.sweeper.SweepInput(input2, defaultFeePref) if err != nil { t.Fatal(err) } // Spend inputs of sweep txes and verify that spend channels signal // spends. ctx.backend.mine() // Sweeper should recognize that its sweep tx of the previous run is // spending the input. select { case result := <-spendChan1: if result.Err != nil { t.Fatalf("expected successful sweep") } case <-time.After(defaultTestTimeout): t.Fatalf("no result received") } // Timer tick should trigger republishing a sweep for the remaining // input. ctx.tick() ctx.receiveTx() ctx.backend.mine() select { case result := <-spendChan2: if result.Err != nil { t.Fatalf("expected successful sweep") } case <-time.After(defaultTestTimeout): t.Fatalf("no result received") } // Restart sweeper again. No action is expected. ctx.restartSweeper() // Expect last tx to be republished. ctx.receiveTx() ctx.finish(1) } // TestRestartRemoteSpend asserts that the sweeper picks up sweeping properly after // a restart with remote spend. func TestRestartRemoteSpend(t *testing.T) { ctx := createSweeperTestContext(t) // Sweep input. input1 := spendableInputs[0] if _, err := ctx.sweeper.SweepInput(input1, defaultFeePref); err != nil { t.Fatal(err) } // Sweep another input. input2 := spendableInputs[1] if _, err := ctx.sweeper.SweepInput(input2, defaultFeePref); err != nil { t.Fatal(err) } ctx.tick() sweepTx := ctx.receiveTx() // Restart sweeper. ctx.restartSweeper() // Expect last tx to be republished. ctx.receiveTx() // Replace the sweep tx with a remote tx spending input 1. ctx.backend.deleteUnconfirmed(sweepTx.TxHash()) remoteTx := &wire.MsgTx{ TxIn: []*wire.TxIn{ { PreviousOutPoint: *(input2.OutPoint()), }, }, } if err := ctx.backend.publishTransaction(remoteTx); err != nil { t.Fatal(err) } // Mine remote spending tx. ctx.backend.mine() // Simulate other subsystem (e.g. contract resolver) re-offering input 0. spendChan, err := ctx.sweeper.SweepInput(input1, defaultFeePref) if err != nil { t.Fatal(err) } // Expect sweeper to construct a new tx, because input 1 was spend // remotely. ctx.tick() ctx.receiveTx() ctx.backend.mine() ctx.expectResult(spendChan, nil) ctx.finish(1) } // TestRestartConfirmed asserts that the sweeper picks up sweeping properly after // a restart with a confirm of our own sweep tx. func TestRestartConfirmed(t *testing.T) { ctx := createSweeperTestContext(t) // Sweep input. input := spendableInputs[0] if _, err := ctx.sweeper.SweepInput(input, defaultFeePref); err != nil { t.Fatal(err) } ctx.tick() ctx.receiveTx() // Restart sweeper. ctx.restartSweeper() // Expect last tx to be republished. ctx.receiveTx() // Mine the sweep tx. ctx.backend.mine() // Simulate other subsystem (e.g. contract resolver) re-offering input 0. spendChan, err := ctx.sweeper.SweepInput(input, defaultFeePref) if err != nil { t.Fatal(err) } // Here we expect again a successful sweep. ctx.expectResult(spendChan, nil) // Timer started but not needed because spend ntfn was sent. ctx.tick() ctx.finish(1) } // TestRestartRepublish asserts that sweeper republishes the last published // tx on restart. func TestRestartRepublish(t *testing.T) { ctx := createSweeperTestContext(t) _, err := ctx.sweeper.SweepInput(spendableInputs[0], defaultFeePref) if err != nil { t.Fatal(err) } ctx.tick() sweepTx := ctx.receiveTx() // Restart sweeper again. No action is expected. ctx.restartSweeper() republishedTx := ctx.receiveTx() if sweepTx.TxHash() != republishedTx.TxHash() { t.Fatalf("last tx not republished") } // Mine the tx to conclude the test properly. ctx.backend.mine() ctx.finish(1) } // TestRetry tests the sweeper retry flow. func TestRetry(t *testing.T) { ctx := createSweeperTestContext(t) resultChan0, err := ctx.sweeper.SweepInput( spendableInputs[0], defaultFeePref, ) if err != nil { t.Fatal(err) } ctx.tick() // We expect a sweep to be published. ctx.receiveTx() // New block arrives. This should trigger a new sweep attempt timer // start. ctx.notifier.NotifyEpoch(1000) // Offer a fresh input. resultChan1, err := ctx.sweeper.SweepInput( spendableInputs[1], defaultFeePref, ) if err != nil { t.Fatal(err) } ctx.tick() // Two txes are expected to be published, because new and retry inputs // are separated. ctx.receiveTx() ctx.receiveTx() ctx.backend.mine() ctx.expectResult(resultChan0, nil) ctx.expectResult(resultChan1, nil) ctx.finish(1) } // TestGiveUp asserts that the sweeper gives up on an input if it can't be swept // after a configured number of attempts.a func TestGiveUp(t *testing.T) { ctx := createSweeperTestContext(t) resultChan0, err := ctx.sweeper.SweepInput( spendableInputs[0], defaultFeePref, ) if err != nil { t.Fatal(err) } ctx.tick() // We expect a sweep to be published at height 100 (mockChainIOHeight). ctx.receiveTx() // Because of MaxSweepAttemps, two more sweeps will be attempted. We // configured exponential back-off without randomness for the test. The // second attempt, we expect to happen at 101. The third attempt at 103. // At that point, the input is expected to be failed. // Second attempt ctx.notifier.NotifyEpoch(101) ctx.tick() ctx.receiveTx() // Third attempt ctx.notifier.NotifyEpoch(103) ctx.tick() ctx.receiveTx() ctx.expectResult(resultChan0, ErrTooManyAttempts) ctx.backend.mine() ctx.finish(1) } // TestDifferentFeePreferences ensures that the sweeper can have different // transactions for different fee preferences. These transactions should be // broadcast from highest to lowest fee rate. func TestDifferentFeePreferences(t *testing.T) { ctx := createSweeperTestContext(t) // Throughout this test, we'll be attempting to sweep three inputs, two // with the higher fee preference, and the last with the lower. We do // this to ensure the sweeper can broadcast distinct transactions for // each sweep with a different fee preference. lowFeePref := FeePreference{ConfTarget: 12} lowFeeRate := chainfee.SatPerKWeight(5000) ctx.estimator.blocksToFee[lowFeePref.ConfTarget] = lowFeeRate highFeePref := FeePreference{ConfTarget: 6} highFeeRate := chainfee.SatPerKWeight(10000) ctx.estimator.blocksToFee[highFeePref.ConfTarget] = highFeeRate input1 := spendableInputs[0] resultChan1, err := ctx.sweeper.SweepInput( input1, Params{Fee: highFeePref}, ) if err != nil { t.Fatal(err) } input2 := spendableInputs[1] resultChan2, err := ctx.sweeper.SweepInput( input2, Params{Fee: highFeePref}, ) if err != nil { t.Fatal(err) } input3 := spendableInputs[2] resultChan3, err := ctx.sweeper.SweepInput( input3, Params{Fee: lowFeePref}, ) if err != nil { t.Fatal(err) } // Start the sweeper's batch ticker, which should cause the sweep // transactions to be broadcast in order of high to low fee preference. ctx.tick() // The first transaction broadcast should be the one spending the higher // fee rate inputs. sweepTx1 := ctx.receiveTx() assertTxFeeRate(t, &sweepTx1, highFeeRate, input1, input2) // The second should be the one spending the lower fee rate inputs. sweepTx2 := ctx.receiveTx() assertTxFeeRate(t, &sweepTx2, lowFeeRate, input3) // With the transactions broadcast, we'll mine a block to so that the // result is delivered to each respective client. ctx.backend.mine() resultChans := []chan Result{resultChan1, resultChan2, resultChan3} for _, resultChan := range resultChans { ctx.expectResult(resultChan, nil) } ctx.finish(1) } // TestPendingInputs ensures that the sweeper correctly determines the inputs // pending to be swept. func TestPendingInputs(t *testing.T) { ctx := createSweeperTestContext(t) // Throughout this test, we'll be attempting to sweep three inputs, two // with the higher fee preference, and the last with the lower. We do // this to ensure the sweeper can return all pending inputs, even those // with different fee preferences. const ( lowFeeRate = 5000 highFeeRate = 10000 ) lowFeePref := FeePreference{ ConfTarget: 12, } ctx.estimator.blocksToFee[lowFeePref.ConfTarget] = lowFeeRate highFeePref := FeePreference{ ConfTarget: 6, } ctx.estimator.blocksToFee[highFeePref.ConfTarget] = highFeeRate input1 := spendableInputs[0] resultChan1, err := ctx.sweeper.SweepInput( input1, Params{Fee: highFeePref}, ) if err != nil { t.Fatal(err) } input2 := spendableInputs[1] _, err = ctx.sweeper.SweepInput( input2, Params{Fee: highFeePref}, ) if err != nil { t.Fatal(err) } input3 := spendableInputs[2] resultChan3, err := ctx.sweeper.SweepInput( input3, Params{Fee: lowFeePref}, ) if err != nil { t.Fatal(err) } // We should expect to see all inputs pending. ctx.assertPendingInputs(input1, input2, input3) // We should expect to see both sweep transactions broadcast. The higher // fee rate sweep should be broadcast first. We'll remove the lower fee // rate sweep to ensure we can detect pending inputs after a sweep. // Once the higher fee rate sweep confirms, we should no longer see // those inputs pending. ctx.tick() ctx.receiveTx() lowFeeRateTx := ctx.receiveTx() ctx.backend.deleteUnconfirmed(lowFeeRateTx.TxHash()) ctx.backend.mine() ctx.expectResult(resultChan1, nil) ctx.assertPendingInputs(input3) // We'll then trigger a new block to rebroadcast the lower fee rate // sweep. Once again we'll ensure those inputs are no longer pending // once the sweep transaction confirms. ctx.backend.notifier.NotifyEpoch(101) ctx.tick() ctx.receiveTx() ctx.backend.mine() ctx.expectResult(resultChan3, nil) ctx.assertPendingInputs() ctx.finish(1) } // TestBumpFeeRBF ensures that the UtxoSweeper can properly handle a fee bump // request for an input it is currently attempting to sweep. When sweeping the // input with the higher fee rate, a replacement transaction is created. func TestBumpFeeRBF(t *testing.T) { ctx := createSweeperTestContext(t) lowFeePref := FeePreference{ConfTarget: 144} lowFeeRate := chainfee.FeePerKwFloor ctx.estimator.blocksToFee[lowFeePref.ConfTarget] = lowFeeRate // We'll first try to bump the fee of an output currently unknown to the // UtxoSweeper. Doing so should result in a lnwallet.ErrNotMine error. _, err := ctx.sweeper.UpdateParams( wire.OutPoint{}, ParamsUpdate{Fee: lowFeePref}, ) if err != lnwallet.ErrNotMine { t.Fatalf("expected error lnwallet.ErrNotMine, got \"%v\"", err) } // We'll then attempt to sweep an input, which we'll use to bump its fee // later on. input := createTestInput( btcutil.SatoshiPerBitcoin, input.CommitmentTimeLock, ) sweepResult, err := ctx.sweeper.SweepInput( &input, Params{Fee: lowFeePref}, ) if err != nil { t.Fatal(err) } // Ensure that a transaction is broadcast with the lower fee preference. ctx.tick() lowFeeTx := ctx.receiveTx() assertTxFeeRate(t, &lowFeeTx, lowFeeRate, &input) // We'll then attempt to bump its fee rate. highFeePref := FeePreference{ConfTarget: 6} highFeeRate := DefaultMaxFeeRate ctx.estimator.blocksToFee[highFeePref.ConfTarget] = highFeeRate // We should expect to see an error if a fee preference isn't provided. _, err = ctx.sweeper.UpdateParams(*input.OutPoint(), ParamsUpdate{}) if err != ErrNoFeePreference { t.Fatalf("expected ErrNoFeePreference, got %v", err) } bumpResult, err := ctx.sweeper.UpdateParams( *input.OutPoint(), ParamsUpdate{Fee: highFeePref}, ) if err != nil { t.Fatalf("unable to bump input's fee: %v", err) } // A higher fee rate transaction should be immediately broadcast. ctx.tick() highFeeTx := ctx.receiveTx() assertTxFeeRate(t, &highFeeTx, highFeeRate, &input) // We'll finish our test by mining the sweep transaction. ctx.backend.mine() ctx.expectResult(sweepResult, nil) ctx.expectResult(bumpResult, nil) ctx.finish(1) } // TestExclusiveGroup tests the sweeper exclusive group functionality. func TestExclusiveGroup(t *testing.T) { ctx := createSweeperTestContext(t) // Sweep three inputs in the same exclusive group. var results []chan Result for i := 0; i < 3; i++ { exclusiveGroup := uint64(1) result, err := ctx.sweeper.SweepInput( spendableInputs[i], Params{ Fee: FeePreference{ConfTarget: 6}, ExclusiveGroup: &exclusiveGroup, }, ) if err != nil { t.Fatal(err) } results = append(results, result) } // We expect all inputs to be published in separate transactions, even // though they share the same fee preference. ctx.tick() for i := 0; i < 3; i++ { sweepTx := ctx.receiveTx() if len(sweepTx.TxOut) != 1 { t.Fatal("expected a single tx out in the sweep tx") } // Remove all txes except for the one that sweeps the first // input. This simulates the sweeps being conflicting. if sweepTx.TxIn[0].PreviousOutPoint != *spendableInputs[0].OutPoint() { ctx.backend.deleteUnconfirmed(sweepTx.TxHash()) } } // Mine the first sweep tx. ctx.backend.mine() // Expect the first input to be swept by the confirmed sweep tx. result0 := <-results[0] if result0.Err != nil { t.Fatal("expected first input to be swept") } // Expect the other two inputs to return an error. They have no chance // of confirming. result1 := <-results[1] if result1.Err != ErrExclusiveGroupSpend { t.Fatal("expected second input to be canceled") } result2 := <-results[2] if result2.Err != ErrExclusiveGroupSpend { t.Fatal("expected third input to be canceled") } } // TestCpfp tests that the sweeper spends cpfp inputs at a fee rate that exceeds // the parent tx fee rate. func TestCpfp(t *testing.T) { ctx := createSweeperTestContext(t) ctx.estimator.updateFees(1000, chainfee.FeePerKwFloor) // Offer an input with an unconfirmed parent tx to the sweeper. The // parent tx pays 3000 sat/kw. hash := chainhash.Hash{1} input := input.MakeBaseInput( &wire.OutPoint{Hash: hash}, input.CommitmentTimeLock, &input.SignDescriptor{ Output: &wire.TxOut{ Value: 330, }, KeyDesc: keychain.KeyDescriptor{ PubKey: testPubKey, }, }, 0, &input.TxInfo{ Weight: 300, Fee: 900, }, ) feePref := FeePreference{ConfTarget: 6} result, err := ctx.sweeper.SweepInput( &input, Params{Fee: feePref, Force: true}, ) require.NoError(t, err) // Because we sweep at 1000 sat/kw, the parent cannot be paid for. We // expect the sweeper to remain idle. ctx.assertNoTick() // Increase the fee estimate to above the parent tx fee rate. ctx.estimator.updateFees(5000, chainfee.FeePerKwFloor) // Signal a new block. This is a trigger for the sweeper to refresh fee // estimates. ctx.notifier.NotifyEpoch(1000) // Now we do expect a sweep transaction to be published with our input // and an attached wallet utxo. ctx.tick() tx := ctx.receiveTx() require.Len(t, tx.TxIn, 2) require.Len(t, tx.TxOut, 1) // As inputs we have 10000 sats from the wallet and 330 sats from the // cpfp input. The sweep tx is weight expected to be 759 units. There is // an additional 300 weight units from the parent to include in the // package, making a total of 1059. At 5000 sat/kw, the required fee for // the package is 5295 sats. The parent already paid 900 sats, so there // is 4395 sat remaining to be paid. The expected output value is // therefore: 10000 + 330 - 4395 = 5935. require.Equal(t, int64(5935), tx.TxOut[0].Value) // Mine the tx and assert that the result is passed back. ctx.backend.mine() ctx.expectResult(result, nil) ctx.finish(1) }