feat(rpc): add eth_chainId to tm rpc (#1364)

rpc/client/client.go

@@ -8,6 +8,8 @@ import (
 	"time"
 
 	sdkerrors "cosmossdk.io/errors"
+	"github.com/dymensionxyz/gerr-cosmos/gerrc"
+	evmostypes "github.com/evmos/evmos/v12/types"
 	abci "github.com/tendermint/tendermint/abci/types"
 	"github.com/tendermint/tendermint/config"
 	tmbytes "github.com/tendermint/tendermint/libs/bytes"
@@ -22,8 +24,6 @@ import (
 	tmtypes "github.com/tendermint/tendermint/types"
 	tm_version "github.com/tendermint/tendermint/version"
 
-	"github.com/dymensionxyz/gerr-cosmos/gerrc"
-
 	"github.com/dymensionxyz/dymint/mempool"
 	"github.com/dymensionxyz/dymint/node"
 	"github.com/dymensionxyz/dymint/types"
@@ -68,6 +68,10 @@ type ResultBlockValidated struct {
 	Result  BlockValidationStatus
 }
 
+type ResultChainId struct {
+	ChainID string
+}
+
 // NewClient returns Client working with given node.
 func NewClient(node *node.Node) *Client {
 	return &Client{
@@ -824,6 +828,14 @@ func (c *Client) CheckTx(ctx context.Context, tx tmtypes.Tx) (*ctypes.ResultChec
 	return &ctypes.ResultCheckTx{ResponseCheckTx: *res}, nil
 }
 
+func (c *Client) ChainID() (*ResultChainId, error) {
+	eip155ChainID, err := evmostypes.ParseChainID(c.node.BlockManager.State.ChainID)
+	if err != nil {
+		return &ResultChainId{}, nil
+	}
+	return &ResultChainId{ChainID: fmt.Sprintf("0x%x", eip155ChainID)}, nil
+}
+
 func (c *Client) BlockValidated(height *int64) (*ResultBlockValidated, error) {
 	_, _, chainID := c.node.P2P.Info()
 	// invalid height

rpc/json/handler.go

@@ -16,6 +16,7 @@ import (
 	"github.com/gorilla/rpc/v2"
 	"github.com/gorilla/rpc/v2/json2"
 
+	"github.com/dymensionxyz/dymint/rpc/client"
 	"github.com/dymensionxyz/dymint/types"
 )
 
@@ -111,6 +112,13 @@ func (h *handler) serveJSONRPCforWS(w http.ResponseWriter, r *http.Request, wsCo
 	// from the declared content-type
 	w.Header().Set("x-content-type-options", "nosniff")
 
+	// it is necessary to return a plain string instead of json object for eth_chainId, since it is required by Metamask to validate chain id
+	if errResult == nil && method == "eth_chainId" {
+		result := (*client.ResultChainId)(rets[0].UnsafePointer())
+		codecReq.WriteResponse(w, result.ChainID)
+		return
+	}
+
 	// Encode the response.
 	if errResult == nil {
 		var raw json.RawMessage

rpc/json/service.go

@@ -110,6 +110,7 @@ func newService(c *client.Client, l types.Logger, opts ...option) *service {
 		"abci_info":            newMethod(s.ABCIInfo),
 		"broadcast_evidence":   newMethod(s.BroadcastEvidence),
 		"block_validated":      newMethod(s.BlockValidated),
+		"eth_chainId":          newMethod(s.ChainId),
 	}
 
 	for _, opt := range opts {
@@ -295,3 +296,7 @@ func (s *service) BlockValidated(req *http.Request, args *blockArgs) (*client.Re
 	fmt.Println(args)
 	return s.client.BlockValidated((*int64)(&args.Height))
 }
+
+func (s *service) ChainId(req *http.Request, args *blockArgs) (*client.ResultChainId, error) {
+	return s.client.ChainID()
+}