@@ -2,11 +2,13 @@ package common
 
 import (
 	"math/big"
+
+	"github.com/iden3/go-merkletree"
 )
 
 type ExitInfo struct {
 	AccountIdx  Idx
-	MerkleProof []byte
+	MerkleProof *merkletree.CircomVerifierProof
 	Balance     *big.Int
 	Nullifier   *big.Int
 }

@@ -130,7 +130,7 @@ return nil
 }
 
 // DeleteCheckpoint removes if exist the checkpoint of the given batchNum
-func (s *StateDB) DeleteCheckpoint(batchNum uint64) error {
+func (s *StateDB) DeleteCheckpoint(batchNum common.BatchNum) error {
 	checkpointPath := s.path + PATHBATCHNUM + strconv.Itoa(int(batchNum))
 
 	if _, err := os.Stat(checkpointPath); os.IsNotExist(err) {
@@ -144,7 +144,7 @@ // Reset resets the StateDB to the checkpoint at the given batchNum. Reset
 // does not delete the checkpoints between old current and the new current,
 // those checkpoints will remain in the storage, and eventually will be
 // deleted when MakeCheckpoint overwrites them.
-func (s *StateDB) Reset(batchNum uint64) error {
+func (s *StateDB) Reset(batchNum common.BatchNum) error {
 	if batchNum == 0 {
 		s.idx = 0
 		return nil
@@ -331,7 +331,7 @@ }
 
 // Reset performs a reset in the LocaStateDB. If fromSynchronizer is true, it
 // gets the state from LocalStateDB.synchronizerStateDB for the given batchNum. If fromSynchronizer is false, get the state from LocalStateDB checkpoints.
-func (l *LocalStateDB) Reset(batchNum uint64, fromSynchronizer bool) error {
+func (l *LocalStateDB) Reset(batchNum common.BatchNum, fromSynchronizer bool) error {
 	if batchNum == 0 {
 		l.idx = 0
 		return nil

@@ -193,13 +193,13 @@ cb, err = sdb.GetCurrentBatch()
 	assert.Nil(t, err)
 	assert.Equal(t, common.BatchNum(4), cb)
 
-	err = sdb.DeleteCheckpoint(uint64(9))
+	err = sdb.DeleteCheckpoint(common.BatchNum(9))
 	assert.Nil(t, err)
-	err = sdb.DeleteCheckpoint(uint64(10))
+	err = sdb.DeleteCheckpoint(common.BatchNum(10))
 	assert.Nil(t, err)
-	err = sdb.DeleteCheckpoint(uint64(9)) // does not exist, should return err
+	err = sdb.DeleteCheckpoint(common.BatchNum(9)) // does not exist, should return err
 	assert.NotNil(t, err)
-	err = sdb.DeleteCheckpoint(uint64(11)) // does not exist, should return err
+	err = sdb.DeleteCheckpoint(common.BatchNum(11)) // does not exist, should return err
 	assert.NotNil(t, err)
 
 	// Create a LocalStateDB from the initial StateDB

@@ -13,20 +13,12 @@
 // keyidx is used as key in the db to store the current Idx
 var keyidx = []byte("idx")
 
-// FUTURE This will be used from common once pending PR is merged
-type ExitInfo struct {
-	Idx       *common.Idx
-	Proof     *merkletree.CircomVerifierProof
-	Nullifier *big.Int
-	Balance   *big.Int
-}
-
 // ProcessTxs process the given L1Txs & L2Txs applying the needed updates to
 // the StateDB depending on the transaction Type. Returns the common.ZKInputs
 // to generate the SnarkProof later used by the BatchBuilder, and if
 // cmpExitTree is set to true, returns common.ExitTreeLeaf that is later used
 // by the Synchronizer to update the HistoryDB.
-func (s *StateDB) ProcessTxs(cmpExitTree bool, l1usertxs, l1coordinatortxs []*common.L1Tx, l2txs []*common.L2Tx) (*common.ZKInputs, []*ExitInfo, error) {
+func (s *StateDB) ProcessTxs(cmpExitTree bool, l1usertxs, l1coordinatortxs []*common.L1Tx, l2txs []*common.L2Tx) (*common.ZKInputs, []*common.ExitInfo, error) {
 	var err error
 	var exitTree *merkletree.MerkleTree
 	exits := make(map[common.Idx]common.Account)
@@ -71,8 +63,8 @@ return nil, nil, nil
 	}
 
 	// once all txs processed (exitTree root frozen), for each leaf
-	// generate ExitInfo data
-	var exitInfos []*ExitInfo
+	// generate common.ExitInfo data
+	var exitInfos []*common.ExitInfo
 	for exitIdx, exitAccount := range exits {
 		// 0. generate MerkleProof
 		p, err := exitTree.GenerateCircomVerifierProof(exitIdx.BigInt(), nil)
@@ -92,12 +84,12 @@ })
 		if err != nil {
 			return nil, nil, err
 		}
-		// 2. generate ExitInfo
-		ei := &ExitInfo{
-			Idx:       &exitIdx,
-			Proof:     p,
-			Nullifier: nullifier,
-			Balance:   exitAccount.Balance,
+		// 2. generate common.ExitInfo
+		ei := &common.ExitInfo{
+			AccountIdx:  exitIdx,
+			MerkleProof: p,
+			Nullifier:   nullifier,
+			Balance:     exitAccount.Balance,
 		}
 		exitInfos = append(exitInfos, ei)
 	}

@@ -57,7 +57,8 @@ panic(err)
 	}
 	//nolint:errcheck
 	defer logger.Sync()
-	log = logger.Sugar()
+	withOptions := logger.WithOptions(zap.AddCallerSkip(1))
+	log = withOptions.Sugar()
 
 	if errorsPath != "" {
 		log.Infof("file where errors will be written: %s", errorsPath)

@@ -52,7 +52,7 @@ }
 
 // Reset tells the TxSelector to get it's internal AccountsDB
 // from the required `batchNum`
-func (txsel *TxSelector) Reset(batchNum uint64) error {
+func (txsel *TxSelector) Reset(batchNum common.BatchNum) error {
 	err := txsel.localAccountsDB.Reset(batchNum, true)
 	if err != nil {
 		return err
@@ -61,7 +61,7 @@ return nil
 }
 
 // GetL2TxSelection returns a selection of the L2Txs for the next batch, from the L2DB pool
-func (txsel *TxSelector) GetL2TxSelection(batchNum uint64) ([]*common.PoolL2Tx, error) {
+func (txsel *TxSelector) GetL2TxSelection(batchNum common.BatchNum) ([]*common.PoolL2Tx, error) {
 	// get pending l2-tx from tx-pool
 	l2TxsRaw, err := txsel.l2db.GetPendingTxs() // once l2db ready, maybe use parameter 'batchNum'
 	if err != nil {
@@ -90,7 +90,7 @@ return txs, nil
 }
 
 // GetL1L2TxSelection returns the selection of L1 + L2 txs
-func (txsel *TxSelector) GetL1L2TxSelection(batchNum uint64, l1txs []*common.L1Tx) ([]*common.L1Tx, []*common.L1Tx, []*common.PoolL2Tx, error) {
+func (txsel *TxSelector) GetL1L2TxSelection(batchNum common.BatchNum, l1txs []*common.L1Tx) ([]*common.L1Tx, []*common.L1Tx, []*common.PoolL2Tx, error) {
 	// apply l1-user-tx to localAccountDB
 	//     create new leaves
 	//     update balances
@@ -153,6 +153,9 @@ }
 
 func (txsel *TxSelector) getL2Profitable(txs txs, max uint64) txs {
 	sort.Sort(txs)
+	if len(txs) < int(max) {
+		return txs
+	}
 	return txs[:max]
 }
 func (txsel *TxSelector) createL1OperatorTxForL2Tx(accounts []*common.Account) []*common.L1Tx {