lnd/sweep/tx_input_set_test.go
Joost Jager e01600fdb8
sweep: add wallet inputs to reach dust limit
This commit allows sweeper to sweep inputs that on its own are not able
to form a sweep transaction that meets the dust limit.

This functionality is useful for sweeping small outputs. In the future,
this will be particularly important to sweep anchors. Anchors will
typically be spent with a relatively large fee to pay for the parent tx.
It will then be necessary to attach an additional wallet utxo.
2019-12-17 22:00:39 +01:00

110 lines
2.7 KiB
Go

package sweep
import (
"testing"
"github.com/btcsuite/btcutil"
"github.com/lightningnetwork/lnd/input"
"github.com/lightningnetwork/lnd/lnwallet"
)
// TestTxInputSet tests adding various sized inputs to the set.
func TestTxInputSet(t *testing.T) {
const (
feeRate = 1000
relayFee = 300
maxInputs = 10
)
set := newTxInputSet(nil, feeRate, relayFee, maxInputs)
if set.dustLimit != 537 {
t.Fatalf("incorrect dust limit")
}
// Create a 300 sat input. The fee to sweep this input to a P2WKH output
// is 439 sats. That means that this input yields -139 sats and we
// expect it not to be added.
if set.add(createP2WKHInput(300), false) {
t.Fatal("expected add of negatively yielding input to fail")
}
// A 700 sat input should be accepted into the set, because it yields
// positively.
if !set.add(createP2WKHInput(700), false) {
t.Fatal("expected add of positively yielding input to succeed")
}
// The tx output should now be 700-439 = 261 sats. The dust limit isn't
// reached yet.
if set.outputValue != 261 {
t.Fatal("unexpected output value")
}
if set.dustLimitReached() {
t.Fatal("expected dust limit not yet to be reached")
}
// Add a 1000 sat input. This increases the tx fee to 712 sats. The tx
// output should now be 1000+700 - 712 = 988 sats.
if !set.add(createP2WKHInput(1000), false) {
t.Fatal("expected add of positively yielding input to succeed")
}
if set.outputValue != 988 {
t.Fatal("unexpected output value")
}
if !set.dustLimitReached() {
t.Fatal("expected dust limit to be reached")
}
}
// TestTxInputSetFromWallet tests adding a wallet input to a TxInputSet to reach
// the dust limit.
func TestTxInputSetFromWallet(t *testing.T) {
const (
feeRate = 500
relayFee = 300
maxInputs = 10
)
wallet := &mockWallet{}
set := newTxInputSet(wallet, feeRate, relayFee, maxInputs)
// Add a 700 sat input to the set. It yields positively, but doesn't
// reach the output dust limit.
if !set.add(createP2WKHInput(700), false) {
t.Fatal("expected add of positively yielding input to succeed")
}
if set.dustLimitReached() {
t.Fatal("expected dust limit not yet to be reached")
}
err := set.tryAddWalletInputsIfNeeded()
if err != nil {
t.Fatal(err)
}
if !set.dustLimitReached() {
t.Fatal("expected dust limit to be reached")
}
}
// createP2WKHInput returns a P2WKH test input with the specified amount.
func createP2WKHInput(amt btcutil.Amount) input.Input {
input := createTestInput(int64(amt), input.WitnessKeyHash)
return &input
}
type mockWallet struct {
Wallet
}
func (m *mockWallet) ListUnspentWitness(minconfirms, maxconfirms int32) (
[]*lnwallet.Utxo, error) {
return []*lnwallet.Utxo{
{
AddressType: lnwallet.WitnessPubKey,
Value: 10000,
},
}, nil
}