modulate base fee with Anvil over a period of time (#931)

client/rpc_suite.go

@@ -0,0 +1,67 @@
+package client
+
+import (
+	"fmt"
+	"strconv"
+	"time"
+
+	"github.com/rs/zerolog"
+)
+
+// ModulateBaseFeeOverDuration will cause the gas price to rise or drop to a certain percentage of the starting gas price
+// over the duration specified.
+// Minimum duration is 1 s
+// if spike is true, the gas price will rise to the target price
+// if spike is false, the gas price will drop to the target price
+func (m *RPCClient) ModulateBaseFeeOverDuration(lggr zerolog.Logger, startingBaseFee int64, percentage float64, duration time.Duration, spike bool) error {
+	if duration < time.Second {
+		return fmt.Errorf("duration must be at least 1s")
+	}
+	// Calculate the target gas price
+	targetBaseFee := float64(startingBaseFee) * (1 + percentage)
+	if !spike {
+		targetBaseFee = float64(startingBaseFee) * (1 - percentage)
+	}
+	lggr.Info().
+		Int64("Starting Base Fee", startingBaseFee).
+		Float64("Percentage", percentage).
+		Dur("Duration", duration).
+		Int64("Target Base Fee", int64(targetBaseFee)).
+		Msg("Modulating base fee per gas over duration")
+
+	// Divide the duration into 10 parts and update the gas price every part
+	intTargetBaseFee := int64(targetBaseFee)
+	partUpdate := (intTargetBaseFee - startingBaseFee) / 10
+	partDuration := duration / 10
+	ticker := time.NewTicker(partDuration)
+	defer ticker.Stop()
+	baseFeeToUpdate := startingBaseFee
+	for range ticker.C {
+		lggr.Info().
+			Int64("Base Fee", baseFeeToUpdate).
+			Int64("Updating By", partUpdate).
+			Msg("Updating base fee per gas")
+		baseFeeToUpdate = baseFeeToUpdate + partUpdate
+		if spike {
+			if baseFeeToUpdate > intTargetBaseFee {
+				baseFeeToUpdate = intTargetBaseFee
+			}
+		} else {
+			if baseFeeToUpdate < intTargetBaseFee {
+				baseFeeToUpdate = intTargetBaseFee
+			}
+		}
+		err := m.AnvilSetNextBlockBaseFeePerGas([]interface{}{strconv.FormatInt(baseFeeToUpdate, 10)})
+		if err != nil {
+			return fmt.Errorf("failed to set base fee %d: %w", baseFeeToUpdate, err)
+		}
+		lggr.Info().Int64("NextBlockBaseFeePerGas", baseFeeToUpdate).Msg("Updated base fee per gas")
+		if baseFeeToUpdate == intTargetBaseFee {
+			lggr.Info().
+				Int64("Base Fee", baseFeeToUpdate).
+				Msg("Reached target base fee")
+			return nil
+		}
+	}
+	return fmt.Errorf("failed to reach target base fee %d", intTargetBaseFee)
+}

client/rpc_suite_test.go

@@ -0,0 +1,60 @@
+package client
+
+import (
+	"context"
+	"math/big"
+	"testing"
+	"time"
+
+	"github.com/ethereum/go-ethereum/ethclient"
+	"github.com/stretchr/testify/require"
+
+	"github.com/smartcontractkit/chainlink-testing-framework/logging"
+)
+
+func TestRPCSuite(t *testing.T) {
+	t.Run("(anvil) test we can modulate next block base fee per gas over a duration", func(t *testing.T) {
+		ac, err := StartAnvil([]string{"--balance", "1", "--block-time", "1"})
+		require.NoError(t, err)
+		client, err := ethclient.Dial(ac.URL)
+		require.NoError(t, err)
+		printGasPrices(t, client)
+		// set a base fee
+		anvilClient := NewRPCClient(ac.URL)
+		// set fee for the next block
+		err = anvilClient.AnvilSetNextBlockBaseFeePerGas([]interface{}{"2000000000"})
+		require.NoError(t, err)
+		// mine a block
+		err = anvilClient.AnvilMine(nil)
+		require.NoError(t, err)
+		blockNumber, err := client.BlockNumber(context.Background())
+		require.NoError(t, err)
+		block, err := client.BlockByNumber(context.Background(), big.NewInt(int64(blockNumber)))
+		require.NoError(t, err)
+		// check the base fee of the block
+		require.Equal(t, "2000000000", block.BaseFee().String(), "expected base fee to be 20 gwei")
+		logger := logging.GetTestLogger(t)
+		err = anvilClient.ModulateBaseFeeOverDuration(logger, 2000000000, 0.5, 20*time.Second, true)
+		require.NoError(t, err)
+		// mine a block
+		err = anvilClient.AnvilMine(nil)
+		require.NoError(t, err)
+		blockNumber, err = client.BlockNumber(context.Background())
+		require.NoError(t, err)
+		block, err = client.BlockByNumber(context.Background(), big.NewInt(int64(blockNumber)))
+		require.NoError(t, err)
+		// check the base fee of the block
+		require.Equal(t, "3000000000", block.BaseFee().String(), "expected base fee to be 30 gwei")
+		err = anvilClient.ModulateBaseFeeOverDuration(logger, 3000000000, 0.25, 15*time.Second, false)
+		require.NoError(t, err)
+		// mine a block
+		err = anvilClient.AnvilMine(nil)
+		require.NoError(t, err)
+		blockNumber, err = client.BlockNumber(context.Background())
+		require.NoError(t, err)
+		block, err = client.BlockByNumber(context.Background(), big.NewInt(int64(blockNumber)))
+		require.NoError(t, err)
+		// check the base fee of the block
+		require.Equal(t, "2250000000", block.BaseFee().String(), "expected base fee to be 30 gwei")
+	})
+}