From eca135b40e568c277f10efa581520b6caf3f5276 Mon Sep 17 00:00:00 2001
From: ptrus <peter@u-s.si>
Date: Wed, 20 Nov 2024 10:09:24 +0100
Subject: [PATCH] feat: support eth_maxPriorityFeePerGas query

---
 rpc/eth/api.go         | 9 +++++++++
 rpc/eth/metrics/api.go | 9 +++++++++
 tests/rpc/rpc_test.go  | 9 +++++++++
 3 files changed, 27 insertions(+)

diff --git a/rpc/eth/api.go b/rpc/eth/api.go
index 7abd0f00..e3144a4a 100644
--- a/rpc/eth/api.go
+++ b/rpc/eth/api.go
@@ -64,6 +64,8 @@ type API interface {
 	ChainId() (*hexutil.Big, error)
 	// GasPrice returns a suggestion for a gas price for legacy transactions.
 	GasPrice(ctx context.Context) (*hexutil.Big, error)
+	// MaxPriorityFeePerGas returns a suggestion for a gas tip cap for dynamic fee transactions
+	MaxPriorityFeePerGas(ctx context.Context) (*hexutil.Big, error)
 	// FeeHistory returns the transaction base fee per gas and effective priority fee per gas for the requested/supported block range.
 	FeeHistory(ctx context.Context, blockCount math.HexOrDecimal64, lastBlock ethrpc.BlockNumber, rewardPercentiles []float64) (*gas.FeeHistoryResult, error)
 	// GetBlockTransactionCountByHash returns the number of transactions in the block identified by hash.
@@ -294,6 +296,13 @@ func (api *publicAPI) GasPrice(_ context.Context) (*hexutil.Big, error) {
 	return api.gasPriceOracle.GasPrice(), nil
 }
 
+func (api *publicAPI) MaxPriorityFeePerGas(_ context.Context) (*hexutil.Big, error) {
+	logger := api.Logger.With("method", "eth_maxPriorityFeePerGas")
+	logger.Debug("request")
+
+	return api.gasPriceOracle.GasPrice(), nil
+}
+
 func (api *publicAPI) FeeHistory(_ context.Context, blockCount math.HexOrDecimal64, lastBlock ethrpc.BlockNumber, rewardPercentiles []float64) (*gas.FeeHistoryResult, error) {
 	logger := api.Logger.With("method", "eth_feeHistory", "block_count", blockCount, "last_block", lastBlock, "reward_percentiles", rewardPercentiles)
 	logger.Debug("request")
diff --git a/rpc/eth/metrics/api.go b/rpc/eth/metrics/api.go
index 508dc118..052aad26 100644
--- a/rpc/eth/metrics/api.go
+++ b/rpc/eth/metrics/api.go
@@ -148,6 +148,15 @@ func (m *metricsWrapper) GasPrice(ctx context.Context) (res *hexutil.Big, err er
 	return
 }
 
+// MaxPriorityFeePerGas implements eth.API.
+func (m *metricsWrapper) MaxPriorityFeePerGas(ctx context.Context) (res *hexutil.Big, err error) {
+	r, s, f, i, d := metrics.GetAPIMethodMetrics("eth_maxPriorityFeePerGas")
+	defer metrics.InstrumentCaller(r, s, f, i, d, &err)()
+
+	res, err = m.api.MaxPriorityFeePerGas(ctx)
+	return
+}
+
 // FeeHistory implements eth.API.
 func (m *metricsWrapper) FeeHistory(ctx context.Context, blockCount math.HexOrDecimal64, lastBlock ethrpc.BlockNumber, rewardPercentiles []float64) (res *gas.FeeHistoryResult, err error) {
 	r, s, f, i, d := metrics.GetAPIMethodMetrics("eth_feeHistory")
diff --git a/tests/rpc/rpc_test.go b/tests/rpc/rpc_test.go
index a2d6170b..1b4bfc39 100644
--- a/tests/rpc/rpc_test.go
+++ b/tests/rpc/rpc_test.go
@@ -146,6 +146,15 @@ func TestEth_GasPrice(t *testing.T) {
 	t.Logf("gas price: %v", price)
 }
 
+func TestEth_MaxPriorityFeePerGas(t *testing.T) {
+	ec := localClient(t, false)
+
+	price, err := ec.SuggestGasTipCap(context.Background())
+	require.Nil(t, err, "get maxPriorityFeePerGas")
+
+	t.Logf("max priority fee per gas: %v", price)
+}
+
 func TestEth_FeeHistory(t *testing.T) {
 	ec := localClient(t, false)