@@ -729,8 +729,8 @@ accounts[:],
 	)
 }
 
-// GetAccounts returns a list of accounts from the DB
-func (hdb *HistoryDB) GetAccounts() ([]common.Account, error) {
+// GetAllAccounts returns a list of accounts from the DB
+func (hdb *HistoryDB) GetAllAccounts() ([]common.Account, error) {
 	var accs []*common.Account
 	err := meddler.QueryAll(
 		hdb.db, &accs,

@@ -293,7 +293,7 @@ accs := test.GenAccounts(nAccounts, 0, tokens, nil, nil, batches)
 	err = historyDB.AddAccounts(accs)
 	assert.NoError(t, err)
 	// Fetch accounts
-	fetchedAccs, err := historyDB.GetAccounts()
+	fetchedAccs, err := historyDB.GetAllAccounts()
 	assert.NoError(t, err)
 	// Compare fetched accounts vs generated accounts
 	for i, acc := range fetchedAccs {

@@ -249,7 +249,6 @@ // those checkpoints will remain in the storage, and eventually will be
 // deleted when MakeCheckpoint overwrites them.  `closeCurrent` will close the
 // currently opened db before doing the reset.
 func (s *StateDB) reset(batchNum common.BatchNum, closeCurrent bool) error {
-	checkpointPath := s.path + PathBatchNum + strconv.Itoa(int(batchNum))
 	currentPath := s.path + PathCurrent
 
 	if closeCurrent {
@@ -271,9 +270,19 @@ }
 		s.db = sto
 		s.idx = 255
 		s.currentBatch = batchNum
+
+		if s.mt != nil {
+			// open the MT for the current s.db
+			mt, err := merkletree.NewMerkleTree(s.db.WithPrefix(PrefixKeyMT), s.mt.MaxLevels())
+			if err != nil {
+				return err
+			}
+			s.mt = mt
+		}
 		return nil
 	}
 
+	checkpointPath := s.path + PathBatchNum + strconv.Itoa(int(batchNum))
 	// copy 'BatchNumX' to 'current'
 	err = pebbleMakeCheckpoint(checkpointPath, currentPath)
 	if err != nil {

@@ -289,11 +289,12 @@ batchNum, err := s.historyDB.GetLastBatchNum()
 	if err != nil && err != sql.ErrNoRows {
 		return 0, err
 	}
-	if batchNum != 0 {
-		err = s.stateDB.Reset(batchNum)
-		if err != nil {
-			return 0, err
-		}
+	if err == sql.ErrNoRows {
+		batchNum = 0
+	}
+	err = s.stateDB.Reset(batchNum)
+	if err != nil {
+		return 0, err
 	}
 
 	return blockNum, nil

@@ -7,6 +7,7 @@ "fmt"
 	"io/ioutil"
 	"math/big"
 	"os"
+	"sort"
 	"testing"
 
 	ethCommon "github.com/ethereum/go-ethereum/common"
@@ -32,6 +33,10 @@ func (t *timer) Time() int64 {
 	currentTime := t.time
 	t.time++
 	return currentTime
+}
+
+func accountsCmp(accounts []common.Account) func(i, j int) bool {
+	return func(i, j int) bool { return accounts[i].Idx < accounts[j].Idx }
 }
 
 // Check Sync output and HistoryDB state against expected values generated by
@@ -194,6 +199,80 @@ dbExit.MerkleProof = exit.MerkleProof
 			assert.Equal(t, &exit, dbExit) //nolint:gosec
 		}
 	}
+
+	// Compare accounts from HistoryDB with StateDB (they should match)
+	dbAccounts, err := s.historyDB.GetAllAccounts()
+	require.Nil(t, err)
+	sdbAccounts, err := s.stateDB.GetAccounts()
+	require.Nil(t, err)
+	assertEqualAccountsHistoryDBStateDB(t, dbAccounts, sdbAccounts)
+}
+
+func assertEqualAccountsHistoryDBStateDB(t *testing.T, hdbAccs, sdbAccs []common.Account) {
+	assert.Equal(t, len(hdbAccs), len(sdbAccs))
+	sort.SliceStable(hdbAccs, accountsCmp(hdbAccs))
+	sort.SliceStable(sdbAccs, accountsCmp(sdbAccs))
+	for i := range hdbAccs {
+		hdbAcc := hdbAccs[i]
+		sdbAcc := sdbAccs[i]
+		assert.Equal(t, hdbAcc.Idx, sdbAcc.Idx)
+		assert.Equal(t, hdbAcc.TokenID, sdbAcc.TokenID)
+		assert.Equal(t, hdbAcc.EthAddr, sdbAcc.EthAddr)
+		assert.Equal(t, hdbAcc.PublicKey, sdbAcc.PublicKey)
+	}
+}
+
+// ethAddTokens adds the tokens from the blocks to the blockchain
+func ethAddTokens(blocks []common.BlockData, client *test.Client) {
+	for _, block := range blocks {
+		for _, token := range block.Rollup.AddedTokens {
+			consts := eth.ERC20Consts{
+				Name:     fmt.Sprintf("Token %d", token.TokenID),
+				Symbol:   fmt.Sprintf("TK%d", token.TokenID),
+				Decimals: 18,
+			}
+			tokenConsts[token.TokenID] = consts
+			client.CtlAddERC20(token.EthAddr, consts)
+		}
+	}
+}
+
+// ethAddBlocks adds block data to the smart contracts
+func ethAddBlocks(t *testing.T, blocks []common.BlockData,
+	client *test.Client, clientSetup *test.ClientSetup) {
+	for _, block := range blocks {
+		for _, token := range block.Rollup.AddedTokens {
+			_, err := client.RollupAddTokenSimple(token.EthAddr, clientSetup.RollupVariables.FeeAddToken)
+			require.Nil(t, err)
+		}
+		for _, tx := range block.Rollup.L1UserTxs {
+			client.CtlSetAddr(tx.FromEthAddr)
+			_, err := client.RollupL1UserTxERC20ETH(tx.FromBJJ, int64(tx.FromIdx), tx.LoadAmount, tx.Amount,
+				uint32(tx.TokenID), int64(tx.ToIdx))
+			require.Nil(t, err)
+		}
+		client.CtlSetAddr(clientSetup.AuctionVariables.BootCoordinator)
+		for _, batch := range block.Rollup.Batches {
+			_, err := client.RollupForgeBatch(&eth.RollupForgeBatchArgs{
+				NewLastIdx:            batch.Batch.LastIdx,
+				NewStRoot:             batch.Batch.StateRoot,
+				NewExitRoot:           batch.Batch.ExitRoot,
+				L1CoordinatorTxs:      batch.L1CoordinatorTxs,
+				L1CoordinatorTxsAuths: [][]byte{}, // Intentionally empty
+				L2TxsData:             batch.L2Txs,
+				FeeIdxCoordinator:     batch.Batch.FeeIdxsCoordinator,
+				// Circuit selector
+				VerifierIdx: 0, // Intentionally empty
+				L1Batch:     batch.L1Batch,
+				ProofA:      [2]*big.Int{},    // Intentionally empty
+				ProofB:      [2][2]*big.Int{}, // Intentionally empty
+				ProofC:      [2]*big.Int{},    // Intentionally empty
+			})
+			require.Nil(t, err)
+		}
+		// Mine block and sync
+		client.CtlMineBlock()
+	}
 }
 
 func TestSync(t *testing.T) {
@@ -322,62 +401,14 @@ require.Equal(t, 2, len(blocks[i].Rollup.Batches))
 	require.Equal(t, 3, len(blocks[i].Rollup.Batches[0].L2Txs))
 
 	// Generate extra required data
-	for _, block := range blocks {
-		for _, token := range block.Rollup.AddedTokens {
-			consts := eth.ERC20Consts{
-				Name:     fmt.Sprintf("Token %d", token.TokenID),
-				Symbol:   fmt.Sprintf("TK%d", token.TokenID),
-				Decimals: 18,
-			}
-			tokenConsts[token.TokenID] = consts
-			client.CtlAddERC20(token.EthAddr, consts)
-		}
-	}
+	ethAddTokens(blocks, client)
 
 	err = tc.FillBlocksExtra(blocks, &tilCfgExtra)
 	assert.Nil(t, err)
 	tc.FillBlocksL1UserTxsBatchNum(blocks)
 
 	// Add block data to the smart contracts
-	for _, block := range blocks {
-		for _, token := range block.Rollup.AddedTokens {
-			_, err := client.RollupAddTokenSimple(token.EthAddr, clientSetup.RollupVariables.FeeAddToken)
-			require.Nil(t, err)
-		}
-		for _, tx := range block.Rollup.L1UserTxs {
-			client.CtlSetAddr(tx.FromEthAddr)
-			_, err := client.RollupL1UserTxERC20ETH(tx.FromBJJ, int64(tx.FromIdx), tx.LoadAmount, tx.Amount,
-				uint32(tx.TokenID), int64(tx.ToIdx))
-			require.Nil(t, err)
-		}
-		client.CtlSetAddr(bootCoordAddr)
-		// feeIdxCoordinator := []common.Idx{}
-		// if block.Block.EthBlockNum > 2 {
-		// 	// After blockNum=2 we have some accounts, use them as
-		// 	// coordinator owned to receive fees.
-		// 	feeIdxCoordinator = []common.Idx{common.Idx(256), common.Idx(259)}
-		// }
-		for _, batch := range block.Rollup.Batches {
-			_, err := client.RollupForgeBatch(&eth.RollupForgeBatchArgs{
-				NewLastIdx:            batch.Batch.LastIdx,
-				NewStRoot:             batch.Batch.StateRoot,
-				NewExitRoot:           batch.Batch.ExitRoot,
-				L1CoordinatorTxs:      batch.L1CoordinatorTxs,
-				L1CoordinatorTxsAuths: [][]byte{}, // Intentionally empty
-				L2TxsData:             batch.L2Txs,
-				FeeIdxCoordinator:     batch.Batch.FeeIdxsCoordinator,
-				// Circuit selector
-				VerifierIdx: 0, // Intentionally empty
-				L1Batch:     batch.L1Batch,
-				ProofA:      [2]*big.Int{},    // Intentionally empty
-				ProofB:      [2][2]*big.Int{}, // Intentionally empty
-				ProofC:      [2]*big.Int{},    // Intentionally empty
-			})
-			require.Nil(t, err)
-		}
-		// Mine block and sync
-		client.CtlMineBlock()
-	}
+	ethAddBlocks(t, blocks, client, clientSetup)
 
 	//
 	// Sync to synchronize the current state from the test smart contracts,
@@ -467,25 +498,94 @@ assert.Equal(t, rollupVars, dbRollupVars)
 	assert.Equal(t, auctionVars, dbAuctionVars)
 	assert.Equal(t, wDelayerVars, dbWDelayerVars)
 
-	// TODO: Reorg will be properly tested once we have the mock ethClient implemented
-	/*
-		// Force a Reorg
-		lastSavedBlock, err := historyDB.GetLastBlock()
-		require.Nil(t, err)
+	//
+	// Reorg test
+	//
+
+	// Redo blocks 2-5 (as a reorg) only leaving:
+	// - 2 create account transactions
+	// - 2 add tokens
+	// We add a 6th block so that the synchronizer can detect the reorg
+	set2 := `
+		Type: Blockchain
+
+		AddToken(1)
+		AddToken(2)
+
+		CreateAccountDeposit(1) C: 2000 // Idx=256+1=257
+
+		CreateAccountCoordinator(1) A // Idx=256+0=256
+
+		> batchL1 // forge L1UserTxs{nil}, freeze defined L1UserTxs{1}
+		> batchL1 // forge defined L1UserTxs{1}, freeze L1UserTxs{nil}
+		> block // blockNum=2
+		> block // blockNum=3
+		> block // blockNum=4
+		> block // blockNum=5
+		> block // blockNum=6
+	`
+	tc = til.NewContext(common.RollupConstMaxL1UserTx)
+	tilCfgExtra = til.ConfigExtra{
+		BootCoordAddr: bootCoordAddr,
+		CoordUser:     "A",
+	}
+	blocks, err = tc.GenerateBlocks(set2)
+	require.Nil(t, err)
+
+	for i := 0; i < 4; i++ {
+		client.CtlRollback()
+	}
+	blockNum := client.CtlCurrentBlock()
+	require.Equal(t, int64(1), blockNum)
+
+	// Generate extra required data
+	ethAddTokens(blocks, client)
 
-		lastSavedBlock.EthBlockNum++
-		err = historyDB.AddBlock(lastSavedBlock)
-		require.Nil(t, err)
+	err = tc.FillBlocksExtra(blocks, &tilCfgExtra)
+	assert.Nil(t, err)
+	tc.FillBlocksL1UserTxsBatchNum(blocks)
 
-		lastSavedBlock.EthBlockNum++
-		err = historyDB.AddBlock(lastSavedBlock)
-		require.Nil(t, err)
+	// Add block data to the smart contracts
+	ethAddBlocks(t, blocks, client, clientSetup)
 
-		log.Debugf("Wait for the blockchain to generate some blocks...")
-		time.Sleep(40 * time.Second)
+	// First sync detects the reorg and discards 4 blocks
+	syncBlock, discards, err = s.Sync2(ctx, nil)
+	require.Nil(t, err)
+	expetedDiscards := int64(4)
+	require.Equal(t, &expetedDiscards, discards)
+	require.Nil(t, syncBlock)
 
+	// At this point, the DB only has data up to block 1
+	dbBlock, err := s.historyDB.GetLastBlock()
+	require.Nil(t, err)
+	assert.Equal(t, int64(1), dbBlock.EthBlockNum)
 
-		err = s.Sync()
+	// Accounts in HistoryDB and StateDB must be empty
+	dbAccounts, err := s.historyDB.GetAllAccounts()
+	require.Nil(t, err)
+	sdbAccounts, err := s.stateDB.GetAccounts()
+	require.Nil(t, err)
+	assert.Equal(t, 0, len(dbAccounts))
+	assertEqualAccountsHistoryDBStateDB(t, dbAccounts, sdbAccounts)
+
+	// Sync blocks 2-6
+	for i := 0; i < 5; i++ {
+		syncBlock, discards, err = s.Sync2(ctx, nil)
 		require.Nil(t, err)
-	*/
+		require.Nil(t, discards)
+		require.NotNil(t, syncBlock)
+		assert.Equal(t, int64(2+i), syncBlock.Block.EthBlockNum)
+	}
+
+	dbBlock, err = s.historyDB.GetLastBlock()
+	require.Nil(t, err)
+	assert.Equal(t, int64(6), dbBlock.EthBlockNum)
+
+	// Accounts in HistoryDB and StateDB is only 2 entries
+	dbAccounts, err = s.historyDB.GetAllAccounts()
+	require.Nil(t, err)
+	sdbAccounts, err = s.stateDB.GetAccounts()
+	require.Nil(t, err)
+	assert.Equal(t, 2, len(dbAccounts))
+	assertEqualAccountsHistoryDBStateDB(t, dbAccounts, sdbAccounts)
 }

@@ -67,7 +67,6 @@ }
 
 func (r *RollupBlock) addTransaction(tx *types.Transaction) *types.Transaction {
 	txHash := tx.Hash()
-	fmt.Printf("DBG txHash %v\n", txHash.Hex())
 	r.Txs[txHash] = tx
 	return tx
 }
@@ -552,6 +551,13 @@ //
 // Ethereum
 //
 
+// CtlCurrentBlock returns the current blockNum without checks
+func (c *Client) CtlCurrentBlock() int64 {
+	c.rw.RLock()
+	defer c.rw.RUnlock()
+	return c.blockNum
+}
+
 // EthCurrentBlock returns the current blockNum
 func (c *Client) EthCurrentBlock() (int64, error) {
 	c.rw.RLock()
@@ -822,7 +828,6 @@ data, err := json.Marshal(transactionData{name, value})
 	if err != nil {
 		panic(err)
 	}
-	fmt.Printf("DBG dataJSON: %v\n", string(data))
 	return types.NewTransaction(0, ethCommon.Address{}, nil, 0, nil,
 		data)
 }