Add ChainConfig to ethclient (#1040)

* add ChainConfig to ethclient

* return ChainConfig

* return ChainConfig in internal api

* Revert "return ChainConfig in internal api"

This reverts commit c64d231.

* Revert "return ChainConfig"

This reverts commit 0071f64.

Author: cam-schultz

ethclient/ethclient.go

@@ -38,6 +38,7 @@ import (
 	"github.com/ava-labs/subnet-evm/accounts/abi/bind"
 	"github.com/ava-labs/subnet-evm/core/types"
 	"github.com/ava-labs/subnet-evm/interfaces"
+	"github.com/ava-labs/subnet-evm/params"
 	"github.com/ava-labs/subnet-evm/rpc"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
@@ -69,6 +70,7 @@ var (
 type Client interface {
 	Client() *rpc.Client
 	Close()
+	ChainConfig(context.Context) (*params.ChainConfigWithUpgradesJSON, error)
 	ChainID(context.Context) (*big.Int, error)
 	BlockByHash(context.Context, common.Hash) (*types.Block, error)
 	BlockByNumber(context.Context, *big.Int) (*types.Block, error)
@@ -141,6 +143,16 @@ func (ec *client) Client() *rpc.Client {
 
 // Blockchain Access
 
+// ChainConfig retrieves the current chain config.
+func (ec *client) ChainConfig(ctx context.Context) (*params.ChainConfigWithUpgradesJSON, error) {
+	var result *params.ChainConfigWithUpgradesJSON
+	err := ec.c.CallContext(ctx, &result, "eth_getChainConfig")
+	if err != nil {
+		return nil, err
+	}
+	return result, err
+}
+
 // ChainID retrieves the current chain ID for transaction replay protection.
 func (ec *client) ChainID(ctx context.Context) (*big.Int, error) {
 	var result hexutil.Big