Add backward compatibility for EIP-1898 getBalance method

Signed-off-by: Luca Georges Francois <luca.georges-francois@epitech.eu>

jsonrpc/codec.go

@@ -3,6 +3,7 @@ package jsonrpc
 import (
 	"encoding/json"
 	"fmt"
+	"strconv"
 	"strings"
 
 	"github.com/0xPolygon/polygon-sdk/types"
@@ -103,13 +104,61 @@ const (
 type BlockNumber int64
 
 type BlockNumberOrHash struct {
-	BlockNumber      BlockNumber
-	BlockHash        types.Hash
-	RequireCanonical bool
+	BlockNumber *BlockNumber `json:"blockNumber,omitempty"`
+	BlockHash   *types.Hash  `json:"blockHash,omitempty"`
 }
 
-func (h *BlockNumberOrHash) Extract() {
+func (bnh *BlockNumberOrHash) Unmarshal(input *interface{}) error {
+	var placeholder BlockNumberOrHash
 
+	data, err := json.Marshal(*input)
+	if err != nil {
+		return fmt.Errorf("failed to serialize input: %v", err)
+	}
+
+	err = json.Unmarshal(data, &placeholder)
+	if err != nil {
+		var keyword string
+		err = json.Unmarshal(data, &keyword)
+		if err == nil {
+			// Try to extract keyword
+			switch keyword {
+			case "pending":
+				n := PendingBlockNumber
+				bnh.BlockNumber = &n
+				return nil
+			case "latest":
+				n := LatestBlockNumber
+				bnh.BlockNumber = &n
+				return nil
+			case "earliest":
+				n := EarliestBlockNumber
+				bnh.BlockNumber = &n
+				return nil
+			default:
+				// Try to extract hex number
+				s, ok := (*input).(string)
+				if !ok {
+					return fmt.Errorf("input cannot be converted to string")
+				}
+				number, err := strconv.ParseInt(s[2:], 16, 64)
+				if err != nil {
+					return fmt.Errorf("failed to convert hex string to int64: %v", err)
+				}
+				bnh.BlockNumber = (*BlockNumber)(&number)
+				return nil
+			}
+		}
+	}
+
+	// Try to extract object
+	bnh.BlockNumber = placeholder.BlockNumber
+	bnh.BlockHash = placeholder.BlockHash
+	return nil
+}
+
+func (bnh *BlockNumberOrHash) GetNumber() BlockNumber {
+	return *bnh.BlockNumber
 }
 
 func stringToBlockNumber(str string) (BlockNumber, error) {

jsonrpc/eth_endpoint.go

@@ -550,34 +550,33 @@ func (e *Eth) GetLogs(filterOptions *LogFilter) (interface{}, error) {
 	return result, nil
 }
 
-// GetBalance returns the account's balance at the referenced block
-func (e *Eth) GetBalance(
-	address types.Address,
-	filter *BlockNumberOrHash,
-) (interface{}, error) {
-	var number *BlockNumber
-	var blockHash string
+// GetBalance returns the account's balance at the referenced block.
+func (e *Eth) GetBalance(address types.Address, filter interface{}) (interface{}, error) {
+	var bnh BlockNumberOrHash
 	var header *types.Header
 	var err error
 
 	if filter == nil {
-		number, _ = createBlockNumberPointer("latest")
+		bnh.BlockNumber, _ = createBlockNumberPointer("latest")
 	} else {
-		number = &filter.BlockNumber
+		err = bnh.Unmarshal(&filter)
+		if err != nil {
+			return nil, fmt.Errorf("failed to decode filter: %v", err)
+		}
 	}
 
-	if filter != nil && filter.BlockHash != types.ZeroHash {
-		block, ok := e.d.store.GetBlockByHash(filter.BlockHash, false)
+	if bnh.BlockNumber != nil {
+		header, err = e.d.getBlockHeaderImpl(*bnh.BlockNumber)
+		if err != nil {
+			return nil, err
+		}
+	} else {
+		block, ok := e.d.store.GetBlockByHash(*bnh.BlockHash, false)
 		if !ok {
-			return nil, fmt.Errorf("could not find block referenced by the hash %s", blockHash)
+			return nil, fmt.Errorf("could not find block referenced by the hash %s", bnh.BlockHash.String())
 		}
 
 		header = block.Header
-	} else {
-		header, err = e.d.getBlockHeaderImpl(*number)
-		if err != nil {
-			return nil, err
-		}
 	}
 
 	acc, err := e.d.store.GetAccount(header.StateRoot, address)

jsonrpc/eth_endpoint_test.go

@@ -425,12 +425,14 @@ func TestEth_State_GetBalance(t *testing.T) {
 	if err != nil {
 		assert.Error(t, err)
 	}
-	balance, err := dispatcher.endpoints.Eth.GetBalance(addr0, &BlockNumberOrHash{BlockNumber: *blockNumber})
+	param := BlockNumberOrHash{BlockNumber: blockNumber}
+	balance, err := dispatcher.endpoints.Eth.GetBalance(addr0, &param)
 	assert.NoError(t, err)
 	assert.Equal(t, balance, argBigPtr(big.NewInt(100)))
 
 	// address not found
-	balance, err = dispatcher.endpoints.Eth.GetBalance(addr1, &BlockNumberOrHash{BlockNumber: *blockNumber})
+	param = BlockNumberOrHash{BlockNumber: blockNumber}
+	balance, err = dispatcher.endpoints.Eth.GetBalance(addr1, &param)
 	assert.NoError(t, err)
 	assert.Equal(t, balance, argUintPtr(0))