[api] impl eth_blobBaseFee (#4528)

Author: envestcc

api/web3server.go

@@ -26,6 +26,7 @@ import (
 	"google.golang.org/grpc/status"
 
 	"github.com/iotexproject/iotex-core/v2/action"
+	"github.com/iotexproject/iotex-core/v2/action/protocol"
 	rewardingabi "github.com/iotexproject/iotex-core/v2/action/protocol/rewarding/ethabi"
 	stakingabi "github.com/iotexproject/iotex-core/v2/action/protocol/staking/ethabi"
 	apitypes "github.com/iotexproject/iotex-core/v2/api/types"
@@ -170,6 +171,8 @@ func (svr *web3Handler) handleWeb3Req(ctx context.Context, web3Req *gjson.Result
 		res, err = svr.maxPriorityFee()
 	case "eth_feeHistory":
 		res, err = svr.feeHistory(ctx, web3Req)
+	case "eth_blobBaseFee":
+		res, err = svr.blobBaseFee()
 	case "eth_getBlockByHash":
 		res, err = svr.getBlockByHash(web3Req)
 	case "eth_chainId":
@@ -368,6 +371,14 @@ func (svr *web3Handler) getChainID() (interface{}, error) {
 	return uint64ToHex(uint64(svr.coreService.EVMNetworkID())), nil
 }
 
+func (svr *web3Handler) blobBaseFee() (interface{}, error) {
+	blk, err := svr.coreService.BlockByHeight(svr.coreService.TipHeight())
+	if err != nil {
+		return nil, err
+	}
+	return bigIntToHex(protocol.CalcBlobFee(protocol.CalcExcessBlobGas(blk.Block.ExcessBlobGas(), blk.Block.BlobGasUsed()))), nil
+}
+
 func (svr *web3Handler) getBlockNumber() (interface{}, error) {
 	return uint64ToHex(svr.coreService.TipHeight()), nil
 }

api/web3server_integrity_test.go

@@ -161,6 +161,10 @@ func TestWeb3ServerIntegrity(t *testing.T) {
 	t.Run("eth_feeHistory", func(t *testing.T) {
 		feeHistory(t, handler, bc, dao, actPool)
 	})
+
+	t.Run("eth_blobBaseFee", func(t *testing.T) {
+		blobBaseFee(t, handler, bc, dao, actPool)
+	})
 }
 
 func setupTestServer() (*ServerV2, blockchain.Blockchain, blockdao.BlockDAO, actpool.ActPool, func()) {
@@ -849,3 +853,22 @@ func feeHistory(t *testing.T, handler *hTTPHandler, bc blockchain.Blockchain, da
   }`, oldnest), string(actual))
 	}
 }
+
+func blobBaseFee(t *testing.T, handler *hTTPHandler, bc blockchain.Blockchain, dao blockdao.BlockDAO, actPool actpool.ActPool) {
+	require := require.New(t)
+	for _, test := range []struct {
+		params   string
+		expected int
+	}{
+		{`[]`, 1},
+	} {
+		result := serveTestHTTP(require, handler, "eth_blobBaseFee", test.params)
+		if test.expected == 0 {
+			require.Nil(result)
+			continue
+		}
+		actual, ok := result.(string)
+		require.True(ok)
+		require.Equal("0x1", actual)
+	}
+}

api/web3server_utils.go

@@ -60,10 +60,7 @@ func uint64ToHex(val uint64) string {
 }
 
 func bigIntToHex(b *big.Int) string {
-	if b == nil {
-		return "0x0"
-	}
-	if b.Sign() == 0 {
+	if b == nil || b.Sign() == 0 {
 		return "0x0"
 	}
 	return "0x" + b.Text(16)