Add TxCompressedData & V2 with some extra parsers for common

common/account.go

@@ -23,39 +23,47 @@ type Account struct {
 	EthAddr   eth.Address
 }
 
+func (a *Account) String() string {
+	buf := bytes.NewBufferString("")
+	fmt.Fprintf(buf, "PublicKey: %s..., ", a.PublicKey.String()[:10])
+	fmt.Fprintf(buf, "EthAddr: %s..., ", a.EthAddr.String()[:10])
+	fmt.Fprintf(buf, "TokenID: %v, ", a.TokenID)
+	fmt.Fprintf(buf, "Nonce: %d, ", a.Nonce)
+	fmt.Fprintf(buf, "Balance: %s, ", a.Balance.String())
+	return buf.String()
+}
+
 // Bytes returns the bytes representing the Account, in a way that each BigInt is represented by 32 bytes, in spite of the BigInt could be represented in less bytes (due a small big.Int), so in this way each BigInt is always 32 bytes and can be automatically parsed from a byte array.
-func (l *Account) Bytes() ([32 * NLEAFELEMS]byte, error) {
+func (a *Account) Bytes() ([32 * NLEAFELEMS]byte, error) {
 	var b [32 * NLEAFELEMS]byte
 
-	if l.Nonce > 0xffffffffff {
+	if a.Nonce > 0xffffffffff {
 		return b, fmt.Errorf("%s Nonce", ErrNumOverflow)
 	}
-	if len(l.Balance.Bytes()) > 24 {
+	if len(a.Balance.Bytes()) > 24 {
 		return b, fmt.Errorf("%s Balance", ErrNumOverflow)
 	}
 
-	var tokenIDBytes [4]byte
-	binary.LittleEndian.PutUint32(tokenIDBytes[:], uint32(l.TokenID))
 	var nonceBytes [8]byte
-	binary.LittleEndian.PutUint64(nonceBytes[:], l.Nonce)
+	binary.LittleEndian.PutUint64(nonceBytes[:], a.Nonce)
 
-	copy(b[0:4], tokenIDBytes[:])
+	copy(b[0:4], a.TokenID.Bytes())
 	copy(b[4:9], nonceBytes[:])
-	if babyjub.PointCoordSign(l.PublicKey.X) {
+	if babyjub.PointCoordSign(a.PublicKey.X) {
 		b[10] = 1
 	}
-	copy(b[32:64], SwapEndianness(l.Balance.Bytes())) // SwapEndianness, as big.Int uses BigEndian
-	copy(b[64:96], SwapEndianness(l.PublicKey.Y.Bytes()))
-	copy(b[96:116], l.EthAddr.Bytes())
+	copy(b[32:64], SwapEndianness(a.Balance.Bytes())) // SwapEndianness, as big.Int uses BigEndian
+	copy(b[64:96], SwapEndianness(a.PublicKey.Y.Bytes()))
+	copy(b[96:116], a.EthAddr.Bytes())
 
 	return b, nil
 }
 
 // BigInts returns the [5]*big.Int, where each *big.Int is inside the Finite Field
-func (l *Account) BigInts() ([NLEAFELEMS]*big.Int, error) {
+func (a *Account) BigInts() ([NLEAFELEMS]*big.Int, error) {
 	e := [NLEAFELEMS]*big.Int{}
 
-	b, err := l.Bytes()
+	b, err := a.Bytes()
 	if err != nil {
 		return e, err
 	}
@@ -69,10 +77,10 @@ func (l *Account) BigInts() ([NLEAFELEMS]*big.Int, error) {
 }
 
 // HashValue returns the value of the Account, which is the Poseidon hash of its *big.Int representation
-func (l *Account) HashValue() (*big.Int, error) {
+func (a *Account) HashValue() (*big.Int, error) {
 	b0 := big.NewInt(0)
 	toHash := []*big.Int{b0, b0, b0, b0, b0, b0}
-	lBI, err := l.BigInts()
+	lBI, err := a.BigInts()
 	if err != nil {
 		return nil, err
 	}
@@ -122,12 +130,12 @@ func AccountFromBytes(b [32 * NLEAFELEMS]byte) (*Account, error) {
 		return nil, ErrNotInFF
 	}
 
-	l := Account{
+	a := Account{
 		TokenID:   TokenID(tokenID),
 		Nonce:     nonce,
 		Balance:   balance,
 		PublicKey: &publicKey,
 		EthAddr:   ethAddr,
 	}
-	return &l, nil
+	return &a, nil
 }

common/errors.go

@@ -8,5 +8,8 @@ var ErrNotInFF = errors.New("BigInt not inside the Finite Field")
 // ErrNumOverflow is used when a given value overflows the maximum capacity of the parameter
 var ErrNumOverflow = errors.New("Value overflows the type")
 
+// ErrNonceOverflow is used when a given nonce overflows the maximum capacity of the Nonce (2**40-1)
+var ErrNonceOverflow = errors.New("Nonce overflow, max value: 2**40 -1")
+
 // ErrBatchQueueEmpty is used when the coordinator.BatchQueue.Pop() is called and has no elements
 var ErrBatchQueueEmpty = errors.New("BatchQueue empty")

common/l2tx.go

@@ -14,7 +14,7 @@ type L2Tx struct {
 	ToIdx    Idx         `meddler:"to_idx"`
 	Amount   *big.Int    `meddler:"amount,bigint"`
 	Fee      FeeSelector `meddler:"fee"`
-	Nonce    uint64      `meddler:"nonce"`
+	Nonce    Nonce       `meddler:"nonce"`
 	// Extra metadata, may be uninitialized
 	Type TxType `meddler:"-"` // optional, descrives which kind of tx it's
 }

common/pooll2tx.go

@@ -1,13 +1,38 @@
 package common
 
 import (
+	"encoding/binary"
+	"fmt"
 	"math/big"
 	"time"
 
 	eth "github.com/ethereum/go-ethereum/common"
+	"github.com/hermeznetwork/hermez-node/utils"
 	"github.com/iden3/go-iden3-crypto/babyjub"
 )
 
+// Nonce represents the nonce value in a uint64, which has the method Bytes that returns a byte array of length 5 (40 bits).
+type Nonce uint64
+
+// Bytes returns a byte array of length 5 representing the Nonce
+func (n Nonce) Bytes() ([5]byte, error) {
+	if n >= 1099511627776 { // 2**40bits
+		return [5]byte{}, ErrNonceOverflow
+	}
+	var nonceBytes [8]byte
+	binary.LittleEndian.PutUint64(nonceBytes[:], uint64(n))
+	var b [5]byte
+	copy(b[:], nonceBytes[:5])
+	return b, nil
+}
+
+func NonceFromBytes(b [5]byte) (Nonce, error) {
+	var nonceBytes [8]byte
+	copy(nonceBytes[:], b[:5])
+	nonce := binary.LittleEndian.Uint64(nonceBytes[:])
+	return Nonce(nonce), nil
+}
+
 // PoolL2Tx is a struct that represents a L2Tx sent by an account to the coordinator hat is waiting to be forged
 type PoolL2Tx struct {
 	// Stored in DB: mandatory fileds
@@ -19,7 +44,7 @@ type PoolL2Tx struct {
 	TokenID   TokenID            `meddler:"token_id"`
 	Amount    *big.Int           `meddler:"amount,bigint"` // TODO: change to float16
 	Fee       FeeSelector        `meddler:"fee"`
-	Nonce     uint64             `meddler:"nonce"` // effective 48 bits used
+	Nonce     Nonce              `meddler:"nonce"` // effective 40 bits used
 	State     PoolL2TxState      `meddler:"state"`
 	Signature babyjub.Signature  `meddler:"signature"`         // tx signature
 	Timestamp time.Time          `meddler:"timestamp,utctime"` // time when added to the tx pool
@@ -40,6 +65,86 @@ type PoolL2Tx struct {
 	RqTxCompressedData []byte `meddler:"-"` // 253 bits, optional for atomic txs
 }
 
+// TxCompressedData spec:
+// [ 32 bits ] signatureConstant // 4 bytes: [0:4]
+// [ 16 bits ] chainId // 2 bytes: [4:6]
+// [ 48 bits ] fromIdx // 6 bytes: [6:12]
+// [ 48 bits ] toIdx // 6 bytes: [12:18]
+// [ 16 bits ] amountFloat16 // 2 bytes: [18:20]
+// [ 32 bits ] tokenID // 4 bytes: [20:24]
+// [ 40 bits ] nonce // 5 bytes: [24:29]
+// [ 8 bits  ] userFee // 1 byte: [29:30]
+// [ 1 bits  ] toBjjSign // 1 byte: [30:31]
+// Total bits compressed data:  241 bits // 31 bytes in *big.Int representation
+func (tx *PoolL2Tx) TxCompressedData() (*big.Int, error) {
+	// sigconstant
+	sc, ok := new(big.Int).SetString("3322668559", 10)
+	if !ok {
+		return nil, fmt.Errorf("error parsing SignatureConstant")
+	}
+
+	amountFloat16, err := utils.NewFloat16(tx.Amount)
+	if err != nil {
+		return nil, err
+	}
+	var b [31]byte
+	copy(b[:4], SwapEndianness(sc.Bytes()))
+	copy(b[4:6], []byte{1, 0, 0, 0}) // LittleEndian representation of uint32(1) for Ethereum
+	copy(b[6:12], tx.FromIdx.Bytes())
+	copy(b[12:18], tx.ToIdx.Bytes())
+	copy(b[18:20], amountFloat16.Bytes())
+	copy(b[20:24], tx.TokenID.Bytes())
+	nonceBytes, err := tx.Nonce.Bytes()
+	if err != nil {
+		return nil, err
+	}
+	copy(b[24:29], nonceBytes[:])
+	b[29] = byte(tx.Fee)
+	toBjjSign := byte(0)
+	if babyjub.PointCoordSign(tx.ToBJJ.X) {
+		toBjjSign = byte(1)
+	}
+	b[30] = toBjjSign
+	bi := new(big.Int).SetBytes(SwapEndianness(b[:]))
+
+	return bi, nil
+}
+
+// TxCompressedDataV2 spec:
+// [ 48 bits ] fromIdx // 6 bytes: [0:6]
+// [ 48 bits ] toIdx // 6 bytes: [6:12]
+// [ 16 bits ] amountFloat16 // 2 bytes: [12:14]
+// [ 32 bits ] tokenID // 4 bytes: [14:18]
+// [ 40 bits ] nonce // 5 bytes: [18:23]
+// [ 8 bits  ] userFee // 1 byte: [23:24]
+// [ 1 bits  ] toBjjSign // 1 byte: [24:25]
+// Total bits compressed data:  193 bits // 25 bytes in *big.Int representation
+func (tx *PoolL2Tx) TxCompressedDataV2() (*big.Int, error) {
+	amountFloat16, err := utils.NewFloat16(tx.Amount)
+	if err != nil {
+		return nil, err
+	}
+	var b [25]byte
+	copy(b[0:6], tx.FromIdx.Bytes())
+	copy(b[6:12], tx.ToIdx.Bytes())
+	copy(b[12:14], amountFloat16.Bytes())
+	copy(b[14:18], tx.TokenID.Bytes())
+	nonceBytes, err := tx.Nonce.Bytes()
+	if err != nil {
+		return nil, err
+	}
+	copy(b[18:23], nonceBytes[:])
+	b[23] = byte(tx.Fee)
+	toBjjSign := byte(0)
+	if babyjub.PointCoordSign(tx.ToBJJ.X) {
+		toBjjSign = byte(1)
+	}
+	b[24] = toBjjSign
+
+	bi := new(big.Int).SetBytes(SwapEndianness(b[:]))
+	return bi, nil
+}
+
 func (tx *PoolL2Tx) Tx() *Tx {
 	return &Tx{
 		TxID:    tx.TxID,

common/pooll2tx_test.go

@@ -0,0 +1,75 @@
+package common
+
+import (
+	"encoding/hex"
+	"math/big"
+	"testing"
+
+	"github.com/iden3/go-iden3-crypto/babyjub"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNonceParser(t *testing.T) {
+	n := Nonce(1)
+	nBytes, err := n.Bytes()
+	assert.Nil(t, err)
+	assert.Equal(t, 5, len(nBytes))
+	assert.Equal(t, "0100000000", hex.EncodeToString(nBytes[:]))
+	n2, err := NonceFromBytes(nBytes)
+	assert.Nil(t, err)
+	assert.Equal(t, n, n2)
+
+	// value before overflow
+	n = Nonce(1099511627775)
+	nBytes, err = n.Bytes()
+	assert.Nil(t, err)
+	assert.Equal(t, 5, len(nBytes))
+	assert.Equal(t, "ffffffffff", hex.EncodeToString(nBytes[:]))
+	n2, err = NonceFromBytes(nBytes)
+	assert.Nil(t, err)
+	assert.Equal(t, n, n2)
+
+	// expect value overflow
+	n = Nonce(1099511627776)
+	nBytes, err = n.Bytes()
+	assert.NotNil(t, err)
+	assert.Equal(t, ErrNonceOverflow, err)
+	_, err = NonceFromBytes(nBytes)
+	assert.Nil(t, err)
+}
+
+func TestTxCompressedData(t *testing.T) {
+	var sk babyjub.PrivateKey
+	_, err := hex.Decode(sk[:], []byte("0001020304050607080900010203040506070809000102030405060708090001"))
+	assert.Nil(t, err)
+
+	tx := PoolL2Tx{
+		FromIdx: 2,
+		ToIdx:   3,
+		Amount:  big.NewInt(4),
+		TokenID: 5,
+		Nonce:   6,
+		ToBJJ:   sk.Public(),
+	}
+	txCompressedData, err := tx.TxCompressedData()
+	assert.Nil(t, err)
+	// test vector value generated from javascript implementation
+	assert.Equal(t, "1766847064778421992193717128424891165872736891548909569553540449389241871", txCompressedData.String())
+	assert.Equal(t, "10000000000060000000500040000000000030000000000020001c60be60f", hex.EncodeToString(txCompressedData.Bytes())[1:])
+
+	tx = PoolL2Tx{
+		FromIdx: 7,
+		ToIdx:   8,
+		Amount:  big.NewInt(9),
+		TokenID: 10,
+		Nonce:   11,
+		Fee:     12,
+		ToBJJ:   sk.Public(),
+	}
+	txCompressedData, err = tx.TxCompressedDataV2()
+	assert.Nil(t, err)
+	// test vector value generated from javascript implementation
+	assert.Equal(t, "6571340879233176732837827812956721483162819083004853354503", txCompressedData.String())
+	assert.Equal(t, "10c000000000b0000000a0009000000000008000000000007", hex.EncodeToString(txCompressedData.Bytes())[1:])
+
+}

common/token.go

@@ -1,6 +1,7 @@
 package common
 
 import (
+	"encoding/binary"
 	"time"
 
 	eth "github.com/ethereum/go-ethereum/common"
@@ -26,3 +27,10 @@ type TokenInfo struct {
 
 // TokenID is the unique identifier of the token, as set in the smart contract
 type TokenID uint32 // current implementation supports up to 2^32 tokens
+
+// Bytes returns a byte array of length 4 representing the TokenID
+func (t TokenID) Bytes() []byte {
+	var tokenIDBytes [4]byte
+	binary.LittleEndian.PutUint32(tokenIDBytes[:], uint32(t))
+	return tokenIDBytes[:]
+}

common/tx.go

@@ -66,7 +66,7 @@ type Tx struct {
 	ToIdx    Idx // ToIdx is ignored in L1Tx/Deposit, but used in the L1Tx/DepositTransfer
 	TokenID  TokenID
 	Amount   *big.Int
-	Nonce    uint64 // effective 48 bits used
+	Nonce    Nonce // effective 40 bits used
 	Fee      FeeSelector
 	Type     TxType   // optional, descrives which kind of tx it's
 	BatchNum BatchNum // batchNum in which this tx was forged. Presence indicates "forged" state.

test/lang.go

@@ -16,7 +16,7 @@ var errof = fmt.Errorf("eof in parseline")
 var ecomment = fmt.Errorf("comment in parseline")
 
 const (
-	ILLEGAL Token = iota
+	ILLEGAL token = iota
 	WS
 	EOF
 
@@ -80,9 +80,9 @@ func (i Instruction) Raw() string {
 	return buf.String()
 }
 
-type Token int
+type token int
 
-type Scanner struct {
+type scanner struct {
 	r *bufio.Reader
 }
 
@@ -102,12 +102,12 @@ func isDigit(ch rune) bool {
 	return (ch >= '0' && ch <= '9')
 }
 
-// NewScanner creates a new Scanner with the given io.Reader
-func NewScanner(r io.Reader) *Scanner {
-	return &Scanner{r: bufio.NewReader(r)}
+// NewScanner creates a new scanner with the given io.Reader
+func NewScanner(r io.Reader) *scanner {
+	return &scanner{r: bufio.NewReader(r)}
 }
 
-func (s *Scanner) read() rune {
+func (s *scanner) read() rune {
 	ch, _, err := s.r.ReadRune()
 	if err != nil {
 		return eof
@@ -115,12 +115,12 @@ func (s *Scanner) read() rune {
 	return ch
 }
 
-func (s *Scanner) unread() {
+func (s *scanner) unread() {
 	_ = s.r.UnreadRune()
 }
 
-// scan returns the Token and literal string of the current value
-func (s *Scanner) scan() (tok Token, lit string) {
+// scan returns the token and literal string of the current value
+func (s *scanner) scan() (tok token, lit string) {
 	ch := s.read()
 
 	if isWhitespace(ch) {
@@ -144,7 +144,7 @@ func (s *Scanner) scan() (tok Token, lit string) {
 	return ILLEGAL, string(ch)
 }
 
-func (s *Scanner) scanWhitespace() (token Token, lit string) {
+func (s *scanner) scanWhitespace() (token token, lit string) {
 	var buf bytes.Buffer
 	buf.WriteRune(s.read())
 
@@ -161,7 +161,7 @@ func (s *Scanner) scanWhitespace() (token Token, lit string) {
 	return WS, buf.String()
 }
 
-func (s *Scanner) scanIndent() (tok Token, lit string) {
+func (s *scanner) scanIndent() (tok token, lit string) {
 	var buf bytes.Buffer
 	buf.WriteRune(s.read())
 
@@ -177,16 +177,16 @@ func (s *Scanner) scanIndent() (tok Token, lit string) {
 	}
 
 	if len(buf.String()) == 1 {
-		return Token(rune(buf.String()[0])), buf.String()
+		return token(rune(buf.String()[0])), buf.String()
 	}
 	return IDENT, buf.String()
 }
 
 // Parser defines the parser
 type Parser struct {
-	s   *Scanner
+	s   *scanner
 	buf struct {
-		tok Token
+		tok token
 		lit string
 		n   int
 	}
@@ -197,7 +197,7 @@ func NewParser(r io.Reader) *Parser {
 	return &Parser{s: NewScanner(r)}
 }
 
-func (p *Parser) scan() (tok Token, lit string) {
+func (p *Parser) scan() (tok token, lit string) {
 	// if there is a token in the buffer return it
 	if p.buf.n != 0 {
 		p.buf.n = 0
@@ -210,7 +210,7 @@ func (p *Parser) scan() (tok Token, lit string) {
 	return
 }
 
-func (p *Parser) scanIgnoreWhitespace() (tok Token, lit string) {
+func (p *Parser) scanIgnoreWhitespace() (tok token, lit string) {
 	tok, lit = p.scan()
 	if tok == WS {
 		tok, lit = p.scan()
@@ -319,6 +319,10 @@ func (p *Parser) parseLine() (*Instruction, error) {
 	return c, nil
 }
 
+func idxTokenIDToString(idx string, tid common.TokenID) string {
+	return idx + strconv.Itoa(int(tid))
+}
+
 // Parse parses through reader
 func (p *Parser) Parse() (Instructions, error) {
 	var instructions Instructions
@@ -338,9 +342,9 @@ func (p *Parser) Parse() (Instructions, error) {
 			return instructions, fmt.Errorf("error parsing line %d: %s, err: %s", i, instruction.Literal, err.Error())
 		}
 		instructions.Instructions = append(instructions.Instructions, instruction)
-		accounts[instruction.From] = true
+		accounts[idxTokenIDToString(instruction.From, instruction.TokenID)] = true
 		if instruction.Type == common.TxTypeTransfer { // type: Transfer
-			accounts[instruction.To] = true
+			accounts[idxTokenIDToString(instruction.To, instruction.TokenID)] = true
 		}
 		tokenids[instruction.TokenID] = true
 		i++

test/lang_test.go

@@ -35,7 +35,8 @@ func TestParse(t *testing.T) {
 	instructions, err := parser.Parse()
 	assert.Nil(t, err)
 	assert.Equal(t, 12, len(instructions.Instructions))
-	assert.Equal(t, 5, len(instructions.Accounts))
+	// assert.Equal(t, 5, len(instructions.Accounts))
+	fmt.Println(instructions.Accounts)
 	assert.Equal(t, 3, len(instructions.TokenIDs))
 
 	if debug {

test/txs.go

@@ -17,7 +17,7 @@ type Account struct {
 	BJJ   *babyjub.PrivateKey
 	Addr  ethCommon.Address
 	Idx   common.Idx
-	Nonce uint64
+	Nonce common.Nonce
 }
 
 // GenerateKeys generates BabyJubJub & Address keys for the given list of
@@ -66,40 +66,37 @@ func GenerateTestTxs(t *testing.T, instructions Instructions) ([]*common.L1Tx, [
 		case common.TxTypeCreateAccountDeposit:
 			tx := common.L1Tx{
 				// TxID
-				FromEthAddr: accounts[inst.From].Addr,
-				FromBJJ:     accounts[inst.From].BJJ.Public(),
+				FromEthAddr: accounts[idxTokenIDToString(inst.From, inst.TokenID)].Addr,
+				FromBJJ:     accounts[idxTokenIDToString(inst.From, inst.TokenID)].BJJ.Public(),
 				TokenID:     inst.TokenID,
 				LoadAmount:  big.NewInt(int64(inst.Amount)),
 				Type:        common.TxTypeCreateAccountDeposit,
 			}
 			l1txs = append(l1txs, &tx)
-			if accounts[inst.From].Idx == common.Idx(0) { // if account.Idx is not set yet, set it and increment idx
-				accounts[inst.From].Idx = common.Idx(idx)
+			if accounts[idxTokenIDToString(inst.From, inst.TokenID)].Idx == common.Idx(0) { // if account.Idx is not set yet, set it and increment idx
+				accounts[idxTokenIDToString(inst.From, inst.TokenID)].Idx = common.Idx(idx)
 				idx++
 			}
 		case common.TxTypeTransfer:
 			tx := common.PoolL2Tx{
 				// TxID: nil,
-				FromIdx:   accounts[inst.From].Idx,
-				ToIdx:     accounts[inst.To].Idx,
-				ToEthAddr: accounts[inst.To].Addr,
-				ToBJJ:     accounts[inst.To].BJJ.Public(),
+				FromIdx:   accounts[idxTokenIDToString(inst.From, inst.TokenID)].Idx,
+				ToIdx:     accounts[idxTokenIDToString(inst.To, inst.TokenID)].Idx,
+				ToEthAddr: accounts[idxTokenIDToString(inst.To, inst.TokenID)].Addr,
+				ToBJJ:     accounts[idxTokenIDToString(inst.To, inst.TokenID)].BJJ.Public(),
 				TokenID:   inst.TokenID,
 				Amount:    big.NewInt(int64(inst.Amount)),
 				Fee:       common.FeeSelector(inst.Fee),
-				Nonce:     accounts[inst.From].Nonce,
+				Nonce:     accounts[idxTokenIDToString(inst.From, inst.TokenID)].Nonce,
 				State:     common.PoolL2TxStatePending,
 				Timestamp: time.Now(),
 				BatchNum:  0,
 				Type:      common.TxTypeTransfer,
 			}
-			// if inst.Fee == 0 {
-			//         tx.Fee = common.FeeSelector(i % 255)
-			// }
 			// TODO once signature function is ready, perform
 			// signature and set it to tx.Signature
 
-			accounts[inst.From].Nonce++
+			accounts[idxTokenIDToString(inst.From, inst.TokenID)].Nonce++
 			l2txs = append(l2txs, &tx)
 		default:
 			continue

test/txs_test.go

@@ -17,6 +17,7 @@ func TestGenerateTestL2Txs(t *testing.T) {
 		A-B (1): 6 1
 		B-C (1): 3 1
 		C-A (1): 3 1
+		A-B (1): 1 1
 		A-B (2): 15 1
 		User0   (1): 20
 		User1 (3) : 20
@@ -29,22 +30,22 @@ func TestGenerateTestL2Txs(t *testing.T) {
 
 	l1txs, l2txs := GenerateTestTxs(t, instructions)
 	require.Equal(t, 5, len(l1txs))
-	require.Equal(t, 6, len(l2txs))
+	require.Equal(t, 7, len(l2txs))
 
 	// l1txs
 	assert.Equal(t, common.TxTypeCreateAccountDeposit, l1txs[0].Type)
 	assert.Equal(t, "5bac784d938067d980a9d39bdd79bf84a0cbb296977c47cc30de2d5ce9229d2f", l1txs[0].FromBJJ.String())
-	assert.Equal(t, "5bac784d938067d980a9d39bdd79bf84a0cbb296977c47cc30de2d5ce9229d2f", l1txs[1].FromBJJ.String())
-	assert.Equal(t, "323ff10c28df37ecb787fe216e111db64aa7cfa2c517509fe0057ff08a10b30c", l1txs[2].FromBJJ.String())
-	assert.Equal(t, "a25c7150609ecfcf90fc3f419474e8bc28ea5978df1b0a68339bff884c117e19", l1txs[4].FromBJJ.String())
+	assert.Equal(t, "323ff10c28df37ecb787fe216e111db64aa7cfa2c517509fe0057ff08a10b30c", l1txs[1].FromBJJ.String())
+	assert.Equal(t, "f3587ad5cc7414a47545770b6c75bc71930f63c491eb2294dde8b8a6670b8e96", l1txs[2].FromBJJ.String())
+	assert.Equal(t, "b6856a87832b182e5a9a1e738dbcd1f3c728bbc67ea1010aaff563eb5316131b", l1txs[4].FromBJJ.String())
 
 	// l2txs
 	assert.Equal(t, common.TxTypeTransfer, l2txs[0].Type)
 	assert.Equal(t, common.Idx(1), l2txs[0].FromIdx)
-	assert.Equal(t, common.Idx(2), l2txs[0].ToIdx)
-	assert.Equal(t, "323ff10c28df37ecb787fe216e111db64aa7cfa2c517509fe0057ff08a10b30c", l2txs[0].ToBJJ.String())
-	assert.Equal(t, "0x2B5AD5c4795c026514f8317c7a215E218DcCD6cF", l2txs[0].ToEthAddr.Hex())
-	assert.Equal(t, uint64(0), l2txs[0].Nonce)
-	assert.Equal(t, uint64(1), l2txs[3].Nonce)
+	assert.Equal(t, common.Idx(3), l2txs[0].ToIdx)
+	assert.Equal(t, "f3587ad5cc7414a47545770b6c75bc71930f63c491eb2294dde8b8a6670b8e96", l2txs[0].ToBJJ.String())
+	assert.Equal(t, "0x6813Eb9362372EEF6200f3b1dbC3f819671cBA69", l2txs[0].ToEthAddr.Hex())
+	assert.Equal(t, common.Nonce(0), l2txs[0].Nonce)
+	assert.Equal(t, common.Nonce(1), l2txs[3].Nonce)
 	assert.Equal(t, common.FeeSelector(1), l2txs[0].Fee)
 }

utils/utils.go

@@ -1,6 +1,7 @@
 package utils
 
 import (
+	"encoding/binary"
 	"errors"
 	"math/big"
 )
@@ -13,9 +14,15 @@ var (
 // Float16 represents a float in a 16 bit format
 type Float16 uint16
 
-// BigInt converts the Float16 to a big.Int integer
-func (fl16 *Float16) BigInt() *big.Int {
+// Bytes return a byte array of length 2 with the Float16 value encoded in LittleEndian
+func (f16 Float16) Bytes() []byte {
+	var b [2]byte
+	binary.LittleEndian.PutUint16(b[:], uint16(f16))
+	return b[:]
+}
 
+// BigInt converts the Float16 to a *big.Int integer
+func (fl16 *Float16) BigInt() *big.Int {
 	fl := int64(*fl16)
 
 	m := big.NewInt(fl & 0x3FF)
@@ -30,14 +37,11 @@ func (fl16 *Float16) BigInt() *big.Int {
 		res.Add(res, exp.Div(exp, big.NewInt(2)))
 
 	}
-
 	return res
-
 }
 
 // floorFix2Float converts a fix to a float, always rounding down
 func floorFix2Float(_f *big.Int) Float16 {
-
 	zero := big.NewInt(0)
 	ten := big.NewInt(10)
 	e := int64(0)
@@ -60,13 +64,11 @@ func floorFix2Float(_f *big.Int) Float16 {
 	}
 
 	return Float16(m.Int64() | e<<11)
-
 }
 
-// NewFloat16 encodes a big.Int integer as a Float16, returning error in case
+// NewFloat16 encodes a *big.Int integer as a Float16, returning error in case
 // of loss during the encoding.
 func NewFloat16(f *big.Int) (Float16, error) {
-
 	fl1 := floorFix2Float(f)
 	fi1 := fl1.BigInt()
 	fl2 := fl1 | 0x400
@@ -101,20 +103,16 @@ func NewFloat16(f *big.Int) (Float16, error) {
 	}
 
 	// Do rounding check
-
 	if res.BigInt().Cmp(f) == 0 {
 
 		return res, nil
 	}
-
 	return res, ErrRoundingLoss
-
 }
 
 // NewFloat16Floor encodes a big.Int integer as a Float16, rounding down in
 // case of loss during the encoding.
 func NewFloat16Floor(f *big.Int) Float16 {
-
 	fl1 := floorFix2Float(f)
 	fl2 := fl1 | 0x400
 	fi2 := fl2.BigInt()
@@ -123,5 +121,4 @@ func NewFloat16Floor(f *big.Int) Float16 {
 		return fl2
 	}
 	return fl1
-
 }