sweepbatcher: unit tests with SQL loopdb as well

This is needed to cover the code of SQLStore with tests.

To achieve compatibility with loopdb (SQLite), the following changes were done:

 - DestAddr is filled to avoid crash in SQL layer
 - Preimage is filled to avoid uniqueness checks by the DB
 - the code working with batch IDs was changed to work correctly
   when batch_id starts with 1 instead of 0
 - SQL swap store has to have a swap with swap_hash from sweep
   to satisfy foreign key constraint of the DB

sweepbatcher/sweep_batcher_test.go

@@ -3,6 +3,7 @@ package sweepbatcher
 import (
 	"context"
 	"errors"
+	"fmt"
 	"sync"
 	"testing"
 	"time"
@@ -30,6 +31,17 @@ const (
 	ntfnBufferSize = 1024
 )
 
+// destAddr is a dummy p2wkh address to use as the destination address for
+// the swaps.
+var destAddr = func() btcutil.Address {
+	p2wkhAddr := "bcrt1qq68r6ff4k4pjx39efs44gcyccf7unqnu5qtjjz"
+	addr, err := btcutil.DecodeAddress(p2wkhAddr, nil)
+	if err != nil {
+		panic(err)
+	}
+	return addr
+}()
+
 func testMuSig2SignSweep(ctx context.Context,
 	protocolVersion loopdb.ProtocolVersion, swapHash lntypes.Hash,
 	paymentAddr [32]byte, nonce []byte, sweepTxPsbt []byte,
@@ -54,21 +66,34 @@ func checkBatcherError(t *testing.T, err error) {
 	}
 }
 
-// TestSweepBatcherBatchCreation tests that sweep requests enter the expected
+// getOnlyBatch makes sure the batcher has exactly one batch and returns it.
+func getOnlyBatch(batcher *Batcher) *batch {
+	if len(batcher.batches) != 1 {
+		panic(fmt.Sprintf("getOnlyBatch called on a batcher having "+
+			"%d batches", len(batcher.batches)))
+	}
+
+	for _, batch := range batcher.batches {
+		return batch
+	}
+
+	panic("unreachable")
+}
+
+// testSweepBatcherBatchCreation tests that sweep requests enter the expected
 // batch based on their timeout distance.
-func TestSweepBatcherBatchCreation(t *testing.T) {
+func testSweepBatcherBatchCreation(t *testing.T, store testStore,
+	batcherStore testBatcherStore) {
+
 	defer test.Guard(t)()
 
 	lnd := test.NewMockLnd()
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	store := loopdb.NewStoreMock(t)
 	sweepStore, err := NewSweepFetcherFromSwapStore(store, lnd.ChainParams)
 	require.NoError(t, err)
 
-	batcherStore := NewStoreMock()
-
 	batcher := NewBatcher(lnd.WalletKit, lnd.ChainNotifier, lnd.Signer,
 		testMuSig2SignSweep, nil, lnd.ChainParams, batcherStore,
 		sweepStore)
@@ -94,6 +119,7 @@ func TestSweepBatcherBatchCreation(t *testing.T) {
 			AmountRequested: 111,
 		},
 
+		DestAddr:    destAddr,
 		SwapInvoice: swapInvoice,
 	}
 
@@ -133,7 +159,11 @@ func TestSweepBatcherBatchCreation(t *testing.T) {
 		SwapContract: loopdb.SwapContract{
 			CltvExpiry:      111 + defaultMaxTimeoutDistance - 1,
 			AmountRequested: 222,
+
+			// Make preimage unique to pass SQL constraints.
+			Preimage: lntypes.Preimage{2},
 		},
+		DestAddr:    destAddr,
 		SwapInvoice: swapInvoice,
 	}
 
@@ -165,7 +195,11 @@ func TestSweepBatcherBatchCreation(t *testing.T) {
 		SwapContract: loopdb.SwapContract{
 			CltvExpiry:      111 + defaultMaxTimeoutDistance + 1,
 			AmountRequested: 333,
+
+			// Make preimage unique to pass SQL constraints.
+			Preimage: lntypes.Preimage{3},
 		},
+		DestAddr:    destAddr,
 		SwapInvoice: swapInvoice,
 	}
 
@@ -211,21 +245,20 @@ func TestSweepBatcherBatchCreation(t *testing.T) {
 	require.True(t, batcherStore.AssertSweepStored(sweepReq3.SwapHash))
 }
 
-// TestSweepBatcherSimpleLifecycle tests the simple lifecycle of the batches
+// testSweepBatcherSimpleLifecycle tests the simple lifecycle of the batches
 // that are created and run by the batcher.
-func TestSweepBatcherSimpleLifecycle(t *testing.T) {
+func testSweepBatcherSimpleLifecycle(t *testing.T, store testStore,
+	batcherStore testBatcherStore) {
+
 	defer test.Guard(t)()
 
 	lnd := test.NewMockLnd()
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	store := loopdb.NewStoreMock(t)
 	sweepStore, err := NewSweepFetcherFromSwapStore(store, lnd.ChainParams)
 	require.NoError(t, err)
 
-	batcherStore := NewStoreMock()
-
 	batcher := NewBatcher(lnd.WalletKit, lnd.ChainNotifier, lnd.Signer,
 		testMuSig2SignSweep, nil, lnd.ChainParams, batcherStore,
 		sweepStore)
@@ -250,6 +283,7 @@ func TestSweepBatcherSimpleLifecycle(t *testing.T) {
 			CltvExpiry:      111,
 			AmountRequested: 111,
 		},
+		DestAddr:        destAddr,
 		SwapInvoice:     swapInvoice,
 		SweepConfTarget: 111,
 	}
@@ -351,21 +385,20 @@ func TestSweepBatcherSimpleLifecycle(t *testing.T) {
 	}, test.Timeout, eventuallyCheckFrequency)
 }
 
-// TestSweepBatcherSweepReentry tests that when an old version of the batch tx
+// testSweepBatcherSweepReentry tests that when an old version of the batch tx
 // gets confirmed the sweep leftovers are sent back to the batcher.
-func TestSweepBatcherSweepReentry(t *testing.T) {
+func testSweepBatcherSweepReentry(t *testing.T, store testStore,
+	batcherStore testBatcherStore) {
+
 	defer test.Guard(t)()
 
 	lnd := test.NewMockLnd()
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	store := loopdb.NewStoreMock(t)
 	sweepStore, err := NewSweepFetcherFromSwapStore(store, lnd.ChainParams)
 	require.NoError(t, err)
 
-	batcherStore := NewStoreMock()
-
 	batcher := NewBatcher(lnd.WalletKit, lnd.ChainNotifier, lnd.Signer,
 		testMuSig2SignSweep, nil, lnd.ChainParams, batcherStore,
 		sweepStore)
@@ -391,6 +424,7 @@ func TestSweepBatcherSweepReentry(t *testing.T) {
 			CltvExpiry:      111,
 			AmountRequested: 111,
 		},
+		DestAddr:        destAddr,
 		SwapInvoice:     swapInvoice,
 		SweepConfTarget: 111,
 	}
@@ -413,7 +447,11 @@ func TestSweepBatcherSweepReentry(t *testing.T) {
 		SwapContract: loopdb.SwapContract{
 			CltvExpiry:      111,
 			AmountRequested: 222,
+
+			// Make preimage unique to pass SQL constraints.
+			Preimage: lntypes.Preimage{2},
 		},
+		DestAddr:        destAddr,
 		SwapInvoice:     swapInvoice,
 		SweepConfTarget: 111,
 	}
@@ -436,7 +474,11 @@ func TestSweepBatcherSweepReentry(t *testing.T) {
 		SwapContract: loopdb.SwapContract{
 			CltvExpiry:      111,
 			AmountRequested: 333,
+
+			// Make preimage unique to pass SQL constraints.
+			Preimage: lntypes.Preimage{3},
 		},
+		DestAddr:        destAddr,
 		SwapInvoice:     swapInvoice,
 		SweepConfTarget: 111,
 	}
@@ -561,21 +603,20 @@ func TestSweepBatcherSweepReentry(t *testing.T) {
 	require.Equal(t, b.state, Open)
 }
 
-// TestSweepBatcherNonWalletAddr tests that sweep requests that sweep to a non
+// testSweepBatcherNonWalletAddr tests that sweep requests that sweep to a non
 // wallet address enter individual batches.
-func TestSweepBatcherNonWalletAddr(t *testing.T) {
+func testSweepBatcherNonWalletAddr(t *testing.T, store testStore,
+	batcherStore testBatcherStore) {
+
 	defer test.Guard(t)()
 
 	lnd := test.NewMockLnd()
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	store := loopdb.NewStoreMock(t)
 	sweepStore, err := NewSweepFetcherFromSwapStore(store, lnd.ChainParams)
 	require.NoError(t, err)
 
-	batcherStore := NewStoreMock()
-
 	batcher := NewBatcher(lnd.WalletKit, lnd.ChainNotifier, lnd.Signer,
 		testMuSig2SignSweep, nil, lnd.ChainParams, batcherStore,
 		sweepStore)
@@ -601,6 +642,7 @@ func TestSweepBatcherNonWalletAddr(t *testing.T) {
 			AmountRequested: 111,
 		},
 		IsExternalAddr: true,
+		DestAddr:       destAddr,
 		SwapInvoice:    swapInvoice,
 	}
 
@@ -640,7 +682,11 @@ func TestSweepBatcherNonWalletAddr(t *testing.T) {
 		SwapContract: loopdb.SwapContract{
 			CltvExpiry:      111 + defaultMaxTimeoutDistance - 1,
 			AmountRequested: 222,
+
+			// Make preimage unique to pass SQL constraints.
+			Preimage: lntypes.Preimage{2},
 		},
+		DestAddr:       destAddr,
 		SwapInvoice:    swapInvoice,
 		IsExternalAddr: true,
 	}
@@ -677,7 +723,11 @@ func TestSweepBatcherNonWalletAddr(t *testing.T) {
 		SwapContract: loopdb.SwapContract{
 			CltvExpiry:      111 + defaultMaxTimeoutDistance + 1,
 			AmountRequested: 333,
+
+			// Make preimage unique to pass SQL constraints.
+			Preimage: lntypes.Preimage{3},
 		},
+		DestAddr:       destAddr,
 		SwapInvoice:    swapInvoice,
 		IsExternalAddr: true,
 	}
@@ -729,21 +779,20 @@ func TestSweepBatcherNonWalletAddr(t *testing.T) {
 	require.True(t, batcherStore.AssertSweepStored(sweepReq3.SwapHash))
 }
 
-// TestSweepBatcherComposite tests that sweep requests that sweep to both wallet
+// testSweepBatcherComposite tests that sweep requests that sweep to both wallet
 // addresses and non-wallet addresses enter the correct batches.
-func TestSweepBatcherComposite(t *testing.T) {
+func testSweepBatcherComposite(t *testing.T, store testStore,
+	batcherStore testBatcherStore) {
+
 	defer test.Guard(t)()
 
 	lnd := test.NewMockLnd()
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	store := loopdb.NewStoreMock(t)
 	sweepStore, err := NewSweepFetcherFromSwapStore(store, lnd.ChainParams)
 	require.NoError(t, err)
 
-	batcherStore := NewStoreMock()
-
 	batcher := NewBatcher(lnd.WalletKit, lnd.ChainNotifier, lnd.Signer,
 		testMuSig2SignSweep, nil, lnd.ChainParams, batcherStore,
 		sweepStore)
@@ -769,6 +818,7 @@ func TestSweepBatcherComposite(t *testing.T) {
 			AmountRequested: 111,
 		},
 
+		DestAddr:    destAddr,
 		SwapInvoice: swapInvoice,
 	}
 
@@ -792,7 +842,11 @@ func TestSweepBatcherComposite(t *testing.T) {
 		SwapContract: loopdb.SwapContract{
 			CltvExpiry:      111 + defaultMaxTimeoutDistance - 1,
 			AmountRequested: 222,
+
+			// Make preimage unique to pass SQL constraints.
+			Preimage: lntypes.Preimage{2},
 		},
+		DestAddr:    destAddr,
 		SwapInvoice: swapInvoice,
 	}
 
@@ -816,7 +870,11 @@ func TestSweepBatcherComposite(t *testing.T) {
 		SwapContract: loopdb.SwapContract{
 			CltvExpiry:      111 + defaultMaxTimeoutDistance - 3,
 			AmountRequested: 333,
+
+			// Make preimage unique to pass SQL constraints.
+			Preimage: lntypes.Preimage{3},
 		},
+		DestAddr:       destAddr,
 		SwapInvoice:    swapInvoice,
 		IsExternalAddr: true,
 	}
@@ -841,7 +899,11 @@ func TestSweepBatcherComposite(t *testing.T) {
 		SwapContract: loopdb.SwapContract{
 			CltvExpiry:      111 + defaultMaxTimeoutDistance + 1,
 			AmountRequested: 444,
+
+			// Make preimage unique to pass SQL constraints.
+			Preimage: lntypes.Preimage{4},
 		},
+		DestAddr:    destAddr,
 		SwapInvoice: swapInvoice,
 	}
 
@@ -865,7 +927,11 @@ func TestSweepBatcherComposite(t *testing.T) {
 		SwapContract: loopdb.SwapContract{
 			CltvExpiry:      111 + defaultMaxTimeoutDistance + 5,
 			AmountRequested: 555,
+
+			// Make preimage unique to pass SQL constraints.
+			Preimage: lntypes.Preimage{5},
 		},
+		DestAddr:    destAddr,
 		SwapInvoice: swapInvoice,
 	}
 
@@ -889,7 +955,11 @@ func TestSweepBatcherComposite(t *testing.T) {
 		SwapContract: loopdb.SwapContract{
 			CltvExpiry:      111 + defaultMaxTimeoutDistance + 6,
 			AmountRequested: 666,
+
+			// Make preimage unique to pass SQL constraints.
+			Preimage: lntypes.Preimage{6},
 		},
+		DestAddr:       destAddr,
 		SwapInvoice:    swapInvoice,
 		IsExternalAddr: true,
 	}
@@ -1013,9 +1083,11 @@ func makeTestTx(value int64) *wire.MsgTx {
 	return tx
 }
 
-// TestGetFeePortionForSweep tests that the fee portion for a sweep is correctly
+// testGetFeePortionForSweep tests that the fee portion for a sweep is correctly
 // calculated.
-func TestGetFeePortionForSweep(t *testing.T) {
+func testGetFeePortionForSweep(t *testing.T, store testStore,
+	batcherStore testBatcherStore) {
+
 	tests := []struct {
 		name                 string
 		spendTxValue         int64
@@ -1050,19 +1122,19 @@ func TestGetFeePortionForSweep(t *testing.T) {
 	}
 }
 
-// TestRestoringEmptyBatch tests that the batcher can be restored with an empty
+// testRestoringEmptyBatch tests that the batcher can be restored with an empty
 // batch.
-func TestRestoringEmptyBatch(t *testing.T) {
+func testRestoringEmptyBatch(t *testing.T, store testStore,
+	batcherStore testBatcherStore) {
+
 	defer test.Guard(t)()
 
 	lnd := test.NewMockLnd()
 	ctx, cancel := context.WithCancel(context.Background())
 
-	store := loopdb.NewStoreMock(t)
 	sweepStore, err := NewSweepFetcherFromSwapStore(store, lnd.ChainParams)
 	require.NoError(t, err)
 
-	batcherStore := NewStoreMock()
 	_, err = batcherStore.InsertSweepBatch(ctx, &dbBatch{})
 	require.NoError(t, err)
 
@@ -1099,6 +1171,7 @@ func TestRestoringEmptyBatch(t *testing.T) {
 			AmountRequested: 111,
 		},
 
+		DestAddr:    destAddr,
 		SwapInvoice: swapInvoice,
 	}
 
@@ -1138,11 +1211,20 @@ func TestRestoringEmptyBatch(t *testing.T) {
 type loopStoreMock struct {
 	loops map[lntypes.Hash]*loopdb.LoopOut
 	mu    sync.Mutex
+
+	// backend is the store passed to the test. An empty swap with the ID
+	// passed is stored to this place to satisfy SQL foreign key constraint.
+	backend testStore
+
+	// preimage is last preimage first byte used in fake swap in backend.
+	// It has to be unique to satisfy SQL constraint.
+	preimage byte
 }
 
-func newLoopStoreMock() *loopStoreMock {
+func newLoopStoreMock(backend testStore) *loopStoreMock {
 	return &loopStoreMock{
-		loops: make(map[lntypes.Hash]*loopdb.LoopOut),
+		loops:   make(map[lntypes.Hash]*loopdb.LoopOut),
+		backend: backend,
 	}
 }
 
@@ -1164,23 +1246,67 @@ func (s *loopStoreMock) putLoopOutSwap(hash lntypes.Hash, out *loopdb.LoopOut) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 
+	_, existed := s.loops[hash]
 	s.loops[hash] = out
+
+	if existed {
+		// The swap exists, no need to create one in backend, since it
+		// stores fake data anyway.
+		return
+	}
+
+	if _, ok := s.backend.(*loopdb.StoreMock); ok {
+		// Do not create a fake loop in loopdb.StoreMock, because it
+		// blocks on notification channels and this is not needed.
+		return
+	}
+
+	// Put a swap with the same ID to backend store to satisfy SQL foreign
+	// key constraint. Don't store the data to ensure it is not used.
+	err := s.backend.CreateLoopOut(context.Background(), hash,
+		&loopdb.LoopOutContract{
+			SwapContract: loopdb.SwapContract{
+				CltvExpiry:      999,
+				AmountRequested: 999,
+
+				// Make preimage unique to pass SQL constraints.
+				Preimage: lntypes.Preimage{s.preimage},
+			},
+
+			DestAddr:    destAddr,
+			SwapInvoice: swapInvoice,
+		},
+	)
+
+	s.backend.AssertLoopOutStored()
+
+	// Make preimage unique to pass SQL constraints.
+	s.preimage++
+
+	if err != nil {
+		panic(err)
+	}
 }
 
-// TestHandleSweepTwice tests that handing the same sweep twice must not
+// AssertLoopOutStored asserts that a swap is stored.
+func (s *loopStoreMock) AssertLoopOutStored() {
+	s.backend.AssertLoopOutStored()
+}
+
+// testHandleSweepTwice tests that handing the same sweep twice must not
 // add it to different batches.
-func TestHandleSweepTwice(t *testing.T) {
+func testHandleSweepTwice(t *testing.T, backend testStore,
+	batcherStore testBatcherStore) {
+
 	defer test.Guard(t)()
 
 	lnd := test.NewMockLnd()
 	ctx, cancel := context.WithCancel(context.Background())
 
-	store := newLoopStoreMock()
+	store := newLoopStoreMock(backend)
 	sweepStore, err := NewSweepFetcherFromSwapStore(store, lnd.ChainParams)
 	require.NoError(t, err)
 
-	batcherStore := NewStoreMock()
-
 	batcher := NewBatcher(lnd.WalletKit, lnd.ChainNotifier, lnd.Signer,
 		testMuSig2SignSweep, nil, lnd.ChainParams, batcherStore,
 		sweepStore)
@@ -1221,6 +1347,7 @@ func TestHandleSweepTwice(t *testing.T) {
 				CltvExpiry:      shortCltv,
 				AmountRequested: 111,
 			},
+			DestAddr:    destAddr,
 			SwapInvoice: swapInvoice,
 		},
 	}
@@ -1244,6 +1371,7 @@ func TestHandleSweepTwice(t *testing.T) {
 				CltvExpiry:      longCltv,
 				AmountRequested: 222,
 			},
+			DestAddr:    destAddr,
 			SwapInvoice: swapInvoice,
 		},
 	}
@@ -1284,6 +1412,7 @@ func TestHandleSweepTwice(t *testing.T) {
 				CltvExpiry:      shortCltv,
 				AmountRequested: 222,
 			},
+			DestAddr:    destAddr,
 			SwapInvoice: swapInvoice,
 		},
 	}
@@ -1300,24 +1429,31 @@ func TestHandleSweepTwice(t *testing.T) {
 			return false
 		}
 
+		// Find the batch with largest ID. It must be the second batch.
+		// Variable batches is a map, not a slice, so we have to visit
+		// all the items and find the one with maximum id.
+		var secondBatch *batch
+		for _, batch := range batches {
+			if secondBatch == nil || batch.id > secondBatch.id {
+				secondBatch = batch
+			}
+		}
+
 		// Make sure the second batch has the second sweep.
-		sweep2, has := batches[1].sweeps[sweepReq2.SwapHash]
+		sweep2, has := secondBatch.sweeps[sweepReq2.SwapHash]
 		if !has {
 			return false
 		}
 
 		// Make sure the second sweep's timeout has been updated.
-		if sweep2.timeout != shortCltv {
-			return false
-		}
-
-		return true
+		return sweep2.timeout == shortCltv
 	}, test.Timeout, eventuallyCheckFrequency)
 
 	// Make sure each batch has one sweep. If the second sweep was added to
 	// both batches, the following check won't pass.
-	require.Equal(t, 1, len(batcher.batches[0].sweeps))
-	require.Equal(t, 1, len(batcher.batches[1].sweeps))
+	for _, batch := range batcher.batches {
+		require.Equal(t, 1, len(batch.sweeps))
+	}
 
 	// Now make the batcher quit by canceling the context.
 	cancel()
@@ -1326,20 +1462,19 @@ func TestHandleSweepTwice(t *testing.T) {
 	checkBatcherError(t, runErr)
 }
 
-// TestRestoringPreservesConfTarget tests that after the batch is written to DB
+// testRestoringPreservesConfTarget tests that after the batch is written to DB
 // and loaded back, its batchConfTarget value is preserved.
-func TestRestoringPreservesConfTarget(t *testing.T) {
+func testRestoringPreservesConfTarget(t *testing.T, store testStore,
+	batcherStore testBatcherStore) {
+
 	defer test.Guard(t)()
 
 	lnd := test.NewMockLnd()
 	ctx, cancel := context.WithCancel(context.Background())
 
-	store := loopdb.NewStoreMock(t)
 	sweepStore, err := NewSweepFetcherFromSwapStore(store, lnd.ChainParams)
 	require.NoError(t, err)
 
-	batcherStore := NewStoreMock()
-
 	batcher := NewBatcher(lnd.WalletKit, lnd.ChainNotifier, lnd.Signer,
 		testMuSig2SignSweep, nil, lnd.ChainParams, batcherStore,
 		sweepStore)
@@ -1373,6 +1508,7 @@ func TestRestoringPreservesConfTarget(t *testing.T) {
 			AmountRequested: 111,
 		},
 
+		DestAddr:        destAddr,
 		SwapInvoice:     swapInvoice,
 		SweepConfTarget: 123,
 	}
@@ -1391,12 +1527,26 @@ func TestRestoringPreservesConfTarget(t *testing.T) {
 	// Once batcher receives sweep request it will eventually spin up a
 	// batch.
 	require.Eventually(t, func() bool {
-		// Make sure that the sweep was stored and we have exactly one
-		// active batch, with one sweep and proper batchConfTarget.
-		return batcherStore.AssertSweepStored(sweepReq.SwapHash) &&
-			len(batcher.batches) == 1 &&
-			len(batcher.batches[0].sweeps) == 1 &&
-			batcher.batches[0].cfg.batchConfTarget == 123
+		// Make sure that the sweep was stored
+		if !batcherStore.AssertSweepStored(sweepReq.SwapHash) {
+			return false
+		}
+
+		// Make sure there is exactly one active batch.
+		if len(batcher.batches) != 1 {
+			return false
+		}
+
+		// Get the batch.
+		batch := getOnlyBatch(batcher)
+
+		// Make sure the batch has one sweep.
+		if len(batch.sweeps) != 1 {
+			return false
+		}
+
+		// Make sure the batch has proper batchConfTarget.
+		return batch.cfg.batchConfTarget == 123
 	}, test.Timeout, eventuallyCheckFrequency)
 
 	// Make sure we have stored the batch.
@@ -1427,13 +1577,25 @@ func TestRestoringPreservesConfTarget(t *testing.T) {
 
 	// Wait for batch to load.
 	require.Eventually(t, func() bool {
-		return batcherStore.AssertSweepStored(sweepReq.SwapHash) &&
-			len(batcher.batches) == 1 &&
-			len(batcher.batches[0].sweeps) == 1
+		// Make sure that the sweep was stored
+		if !batcherStore.AssertSweepStored(sweepReq.SwapHash) {
+			return false
+		}
+
+		// Make sure there is exactly one active batch.
+		if len(batcher.batches) != 1 {
+			return false
+		}
+
+		// Get the batch.
+		batch := getOnlyBatch(batcher)
+
+		// Make sure the batch has one sweep.
+		return len(batch.sweeps) == 1
 	}, test.Timeout, eventuallyCheckFrequency)
 
 	// Make sure batchConfTarget was preserved.
-	require.Equal(t, 123, int(batcher.batches[0].cfg.batchConfTarget))
+	require.Equal(t, 123, int(getOnlyBatch(batcher).cfg.batchConfTarget))
 
 	// Expect registration for spend notification.
 	<-lnd.RegisterSpendChannel
@@ -1456,8 +1618,10 @@ func (f *sweepFetcherMock) FetchSweep(ctx context.Context, hash lntypes.Hash) (
 	return f.store[hash], nil
 }
 
-// TestSweepFetcher tests providing custom sweep fetcher to Batcher.
-func TestSweepFetcher(t *testing.T) {
+// testSweepFetcher tests providing custom sweep fetcher to Batcher.
+func testSweepFetcher(t *testing.T, store testStore,
+	batcherStore testBatcherStore) {
+
 	defer test.Guard(t)()
 
 	lnd := test.NewMockLnd()
@@ -1479,7 +1643,33 @@ func TestSweepFetcher(t *testing.T) {
 		},
 	}
 
-	batcherStore := NewStoreMock()
+	// Create a sweep request.
+	sweepReq := SweepRequest{
+		SwapHash: lntypes.Hash{1, 1, 1},
+		Value:    111,
+		Outpoint: wire.OutPoint{
+			Hash:  chainhash.Hash{1, 1},
+			Index: 1,
+		},
+		Notifier: &dummyNotifier,
+	}
+
+	// Create a swap in the DB. It is needed to satisfy SQL constraints in
+	// case of SQL test. The data is not actually used, since we pass sweep
+	// fetcher, so put different conf target to make sure it is not used.
+	swap := &loopdb.LoopOutContract{
+		SwapContract: loopdb.SwapContract{
+			CltvExpiry:      222,
+			AmountRequested: 222,
+		},
+
+		DestAddr:        destAddr,
+		SwapInvoice:     swapInvoice,
+		SweepConfTarget: 321,
+	}
+	err = store.CreateLoopOut(ctx, sweepReq.SwapHash, swap)
+	require.NoError(t, err)
+	store.AssertLoopOutStored()
 
 	batcher := NewBatcher(lnd.WalletKit, lnd.ChainNotifier, lnd.Signer,
 		testMuSig2SignSweep, nil, lnd.ChainParams, batcherStore,
@@ -1497,17 +1687,6 @@ func TestSweepFetcher(t *testing.T) {
 	// Wait for the batcher to be initialized.
 	<-batcher.initDone
 
-	// Create a sweep request.
-	sweepReq := SweepRequest{
-		SwapHash: lntypes.Hash{1, 1, 1},
-		Value:    111,
-		Outpoint: wire.OutPoint{
-			Hash:  chainhash.Hash{1, 1},
-			Index: 1,
-		},
-		Notifier: &dummyNotifier,
-	}
-
 	// Deliver sweep request to batcher.
 	require.NoError(t, batcher.AddSweep(&sweepReq))
 
@@ -1518,12 +1697,26 @@ func TestSweepFetcher(t *testing.T) {
 	// Once batcher receives sweep request it will eventually spin up a
 	// batch.
 	require.Eventually(t, func() bool {
-		// Make sure that the sweep was stored and we have exactly one
-		// active batch, with one sweep and proper batchConfTarget.
-		return batcherStore.AssertSweepStored(sweepReq.SwapHash) &&
-			len(batcher.batches) == 1 &&
-			len(batcher.batches[0].sweeps) == 1 &&
-			batcher.batches[0].cfg.batchConfTarget == 123
+		// Make sure that the sweep was stored
+		if !batcherStore.AssertSweepStored(sweepReq.SwapHash) {
+			return false
+		}
+
+		// Make sure there is exactly one active batch.
+		if len(batcher.batches) != 1 {
+			return false
+		}
+
+		// Get the batch.
+		batch := getOnlyBatch(batcher)
+
+		// Make sure the batch has one sweep.
+		if len(batch.sweeps) != 1 {
+			return false
+		}
+
+		// Make sure the batch has proper batchConfTarget.
+		return batch.cfg.batchConfTarget == 123
 	}, test.Timeout, eventuallyCheckFrequency)
 
 	// Make sure we have stored the batch.
@@ -1539,21 +1732,20 @@ func TestSweepFetcher(t *testing.T) {
 	checkBatcherError(t, runErr)
 }
 
-// TestSweepBatcherCloseDuringAdding tests that sweep batcher works correctly
+// testSweepBatcherCloseDuringAdding tests that sweep batcher works correctly
 // if it is closed (stops running) during AddSweep call.
-func TestSweepBatcherCloseDuringAdding(t *testing.T) {
+func testSweepBatcherCloseDuringAdding(t *testing.T, store testStore,
+	batcherStore testBatcherStore) {
+
 	defer test.Guard(t)()
 
 	lnd := test.NewMockLnd()
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	store := loopdb.NewStoreMock(t)
 	sweepStore, err := NewSweepFetcherFromSwapStore(store, lnd.ChainParams)
 	require.NoError(t, err)
 
-	batcherStore := NewStoreMock()
-
 	batcher := NewBatcher(lnd.WalletKit, lnd.ChainNotifier, lnd.Signer,
 		testMuSig2SignSweep, nil, lnd.ChainParams, batcherStore,
 		sweepStore)
@@ -1571,8 +1763,12 @@ func TestSweepBatcherCloseDuringAdding(t *testing.T) {
 			SwapContract: loopdb.SwapContract{
 				CltvExpiry:      111,
 				AmountRequested: 111,
+
+				// Make preimage unique to pass SQL constraints.
+				Preimage: lntypes.Preimage{i},
 			},
 
+			DestAddr:    destAddr,
 			SwapInvoice: swapInvoice,
 		}
 
@@ -1634,3 +1830,173 @@ func TestSweepBatcherCloseDuringAdding(t *testing.T) {
 	close(quit)
 	<-registrationChan
 }
+
+// TestSweepBatcherBatchCreation tests that sweep requests enter the expected
+// batch based on their timeout distance.
+func TestSweepBatcherBatchCreation(t *testing.T) {
+	runTests(t, testSweepBatcherBatchCreation)
+}
+
+// TestSweepBatcherSimpleLifecycle tests the simple lifecycle of the batches
+// that are created and run by the batcher.
+func TestSweepBatcherSimpleLifecycle(t *testing.T) {
+	runTests(t, testSweepBatcherSimpleLifecycle)
+}
+
+// TestSweepBatcherSweepReentry tests that when an old version of the batch tx
+// gets confirmed the sweep leftovers are sent back to the batcher.
+func TestSweepBatcherSweepReentry(t *testing.T) {
+	runTests(t, testSweepBatcherSweepReentry)
+}
+
+// TestSweepBatcherNonWalletAddr tests that sweep requests that sweep to a non
+// wallet address enter individual batches.
+func TestSweepBatcherNonWalletAddr(t *testing.T) {
+	runTests(t, testSweepBatcherNonWalletAddr)
+}
+
+// TestSweepBatcherComposite tests that sweep requests that sweep to both wallet
+// addresses and non-wallet addresses enter the correct batches.
+func TestSweepBatcherComposite(t *testing.T) {
+	runTests(t, testSweepBatcherComposite)
+}
+
+// TestGetFeePortionForSweep tests that the fee portion for a sweep is correctly
+// calculated.
+func TestGetFeePortionForSweep(t *testing.T) {
+	runTests(t, testGetFeePortionForSweep)
+}
+
+// TestRestoringEmptyBatch tests that the batcher can be restored with an empty
+// batch.
+func TestRestoringEmptyBatch(t *testing.T) {
+	runTests(t, testRestoringEmptyBatch)
+}
+
+// TestHandleSweepTwice tests that handing the same sweep twice must not
+// add it to different batches.
+func TestHandleSweepTwice(t *testing.T) {
+	runTests(t, testHandleSweepTwice)
+}
+
+// TestRestoringPreservesConfTarget tests that after the batch is written to DB
+// and loaded back, its batchConfTarget value is preserved.
+func TestRestoringPreservesConfTarget(t *testing.T) {
+	runTests(t, testRestoringPreservesConfTarget)
+}
+
+// TestSweepFetcher tests providing custom sweep fetcher to Batcher.
+func TestSweepFetcher(t *testing.T) {
+	runTests(t, testSweepFetcher)
+}
+
+// TestSweepBatcherCloseDuringAdding tests that sweep batcher works correctly
+// if it is closed (stops running) during AddSweep call.
+func TestSweepBatcherCloseDuringAdding(t *testing.T) {
+	runTests(t, testSweepBatcherCloseDuringAdding)
+}
+
+// testBatcherStore is BatcherStore used in tests.
+type testBatcherStore interface {
+	BatcherStore
+
+	// AssertSweepStored asserts that a sweep is stored.
+	AssertSweepStored(id lntypes.Hash) bool
+}
+
+type loopdbBatcherStore struct {
+	BatcherStore
+
+	sweepsSet map[lntypes.Hash]struct{}
+}
+
+// UpsertSweep inserts a sweep into the database, or updates an existing sweep
+// if it already exists. This wrapper was added to update sweepsSet.
+func (s *loopdbBatcherStore) UpsertSweep(ctx context.Context,
+	sweep *dbSweep) error {
+
+	err := s.BatcherStore.UpsertSweep(ctx, sweep)
+	if err == nil {
+		s.sweepsSet[sweep.SwapHash] = struct{}{}
+	}
+	return err
+}
+
+// AssertSweepStored asserts that a sweep is stored.
+func (s *loopdbBatcherStore) AssertSweepStored(id lntypes.Hash) bool {
+	_, has := s.sweepsSet[id]
+	return has
+}
+
+// testStore is loopdb used in tests.
+type testStore interface {
+	loopdb.SwapStore
+
+	// AssertLoopOutStored asserts that a swap is stored.
+	AssertLoopOutStored()
+}
+
+// loopdbStore wraps loopdb.SwapStore and implements testStore interface.
+type loopdbStore struct {
+	loopdb.SwapStore
+
+	t *testing.T
+
+	loopOutStoreChan chan struct{}
+}
+
+// newLoopdbStore creates new loopdbStore instance.
+func newLoopdbStore(t *testing.T, swapStore loopdb.SwapStore) *loopdbStore {
+	return &loopdbStore{
+		SwapStore:        swapStore,
+		t:                t,
+		loopOutStoreChan: make(chan struct{}, 1),
+	}
+}
+
+// CreateLoopOut adds an initiated swap to the store.
+func (s *loopdbStore) CreateLoopOut(ctx context.Context, hash lntypes.Hash,
+	swap *loopdb.LoopOutContract) error {
+
+	err := s.SwapStore.CreateLoopOut(ctx, hash, swap)
+	if err == nil {
+		s.loopOutStoreChan <- struct{}{}
+	}
+
+	return err
+}
+
+// AssertLoopOutStored asserts that a swap is stored.
+func (s *loopdbStore) AssertLoopOutStored() {
+	s.t.Helper()
+
+	select {
+	case <-s.loopOutStoreChan:
+	case <-time.After(test.Timeout):
+		s.t.Fatalf("expected swap to be stored")
+	}
+}
+
+// runTests runs a test with both mock and loopdb.
+func runTests(t *testing.T, testFn func(t *testing.T, store testStore,
+	batcherStore testBatcherStore)) {
+
+	t.Run("mocks", func(t *testing.T) {
+		store := loopdb.NewStoreMock(t)
+		batcherStore := NewStoreMock()
+		testFn(t, store, batcherStore)
+	})
+
+	t.Run("loopdb", func(t *testing.T) {
+		sqlDB := loopdb.NewTestDB(t)
+		typedSqlDB := loopdb.NewTypedStore[Querier](sqlDB)
+		lnd := test.NewMockLnd()
+		batcherStore := NewSQLStore(typedSqlDB, lnd.ChainParams)
+		testStore := newLoopdbStore(t, sqlDB)
+		testBatcherStore := &loopdbBatcherStore{
+			BatcherStore: batcherStore,
+			sweepsSet:    make(map[lntypes.Hash]struct{}),
+		}
+		testFn(t, testStore, testBatcherStore)
+	})
+}