Add fix and update unit tests for header gas limit calculation (#123)

* Add fix and update unit tests for header gas limit calculation for builder blocks

* Fix linter errors

* Add 0x prefix

Author: Wazzymandias

builder/builder.go

@@ -9,6 +9,8 @@ import (
 	"sync"
 	"time"
 
+	"github.com/ethereum/go-ethereum/core"
+
 	bellatrixapi "github.com/attestantio/go-builder-client/api/bellatrix"
 	capellaapi "github.com/attestantio/go-builder-client/api/capella"
 	apiv1 "github.com/attestantio/go-builder-client/api/v1"
@@ -346,8 +348,13 @@ func (b *Builder) OnPayloadAttribute(attrs *types.BuilderPayloadAttributes) erro
 		return fmt.Errorf("could not get validator while submitting block for slot %d - %w", attrs.Slot, err)
 	}
 
+	parentBlock := b.eth.GetBlockByHash(attrs.HeadHash)
+	if parentBlock == nil {
+		return fmt.Errorf("parent block hash not found in block tree given head block hash %s", attrs.HeadHash)
+	}
+
 	attrs.SuggestedFeeRecipient = [20]byte(vd.FeeRecipient)
-	attrs.GasLimit = vd.GasLimit
+	attrs.GasLimit = core.CalcGasLimit(parentBlock.GasLimit(), vd.GasLimit)
 
 	proposerPubkey, err := utils.HexToPubkey(string(vd.Pubkey))
 	if err != nil {
@@ -358,11 +365,6 @@ func (b *Builder) OnPayloadAttribute(attrs *types.BuilderPayloadAttributes) erro
 		return errors.New("backend not Synced")
 	}
 
-	parentBlock := b.eth.GetBlockByHash(attrs.HeadHash)
-	if parentBlock == nil {
-		return fmt.Errorf("parent block hash not found in block tree given head block hash %s", attrs.HeadHash)
-	}
-
 	b.slotMu.Lock()
 	defer b.slotMu.Unlock()
 

builder/builder_test.go

@@ -5,6 +5,8 @@ import (
 	"testing"
 	"time"
 
+	"github.com/ethereum/go-ethereum/core"
+
 	apiv1 "github.com/attestantio/go-builder-client/api/v1"
 	"github.com/attestantio/go-eth2-client/spec/bellatrix"
 	"github.com/attestantio/go-eth2-client/spec/phase0"
@@ -21,6 +23,13 @@ import (
 )
 
 func TestOnPayloadAttributes(t *testing.T) {
+	const (
+		validatorDesiredGasLimit = 30_000_000
+		payloadAttributeGasLimit = 0
+		parentBlockGasLimit      = 29_000_000
+	)
+	expectedGasLimit := core.CalcGasLimit(parentBlockGasLimit, validatorDesiredGasLimit)
+
 	vsk, err := bls.SecretKeyFromBytes(hexutil.MustDecode("0x370bb8c1a6e62b2882f6ec76762a67b39609002076b95aae5b023997cf9b2dc9"))
 	require.NoError(t, err)
 	validator := &ValidatorPrivateData{
@@ -38,7 +47,7 @@ func TestOnPayloadAttributes(t *testing.T) {
 		gvsVd: ValidatorData{
 			Pubkey:       PubkeyHex(testBeacon.validator.Pk.String()),
 			FeeRecipient: feeRecipient,
-			GasLimit:     10,
+			GasLimit:     validatorDesiredGasLimit,
 		},
 	}
 
@@ -54,14 +63,14 @@ func TestOnPayloadAttributes(t *testing.T) {
 		ReceiptsRoot: common.Hash{0x08, 0x20},
 		LogsBloom:    types.Bloom{}.Bytes(),
 		Number:       uint64(10),
-		GasLimit:     uint64(50),
+		GasLimit:     expectedGasLimit,
 		GasUsed:      uint64(100),
 		Timestamp:    uint64(105),
 		ExtraData:    hexutil.MustDecode("0x0042fafc"),
 
 		BaseFeePerGas: big.NewInt(16),
 
-		BlockHash:    common.HexToHash("0xca4147f0d4150183ece9155068f34ee3c375448814e4ca557d482b1d40ee5407"),
+		BlockHash:    common.HexToHash("0x68e516c8827b589fcb749a9e672aa16b9643437459508c467f66a9ed1de66a6c"),
 		Transactions: [][]byte{},
 	}
 
@@ -72,7 +81,7 @@ func TestOnPayloadAttributes(t *testing.T) {
 		Timestamp:             hexutil.Uint64(104),
 		Random:                common.Hash{0x05, 0x10},
 		SuggestedFeeRecipient: common.Address{0x04, 0x10},
-		GasLimit:              uint64(21),
+		GasLimit:              uint64(payloadAttributeGasLimit),
 		Slot:                  uint64(25),
 	}
 
@@ -99,6 +108,7 @@ func TestOnPayloadAttributes(t *testing.T) {
 	time.Sleep(time.Second * 3)
 
 	require.NotNil(t, testRelay.submittedMsg)
+
 	expectedProposerPubkey, err := utils.HexToPubkey(testBeacon.validator.Pk.String())
 	require.NoError(t, err)
 
@@ -108,11 +118,11 @@ func TestOnPayloadAttributes(t *testing.T) {
 		BuilderPubkey:        builder.builderPublicKey,
 		ProposerPubkey:       expectedProposerPubkey,
 		ProposerFeeRecipient: feeRecipient,
-		GasLimit:             uint64(50),
+		GasLimit:             expectedGasLimit,
 		GasUsed:              uint64(100),
 		Value:                &uint256.Int{0x0a},
 	}
-	copy(expectedMessage.BlockHash[:], hexutil.MustDecode("0xca4147f0d4150183ece9155068f34ee3c375448814e4ca557d482b1d40ee5407")[:])
+	copy(expectedMessage.BlockHash[:], hexutil.MustDecode("0x68e516c8827b589fcb749a9e672aa16b9643437459508c467f66a9ed1de66a6c")[:])
 	require.Equal(t, expectedMessage, *testRelay.submittedMsg.Message)
 
 	expectedExecutionPayload := bellatrix.ExecutionPayload{
@@ -134,7 +144,7 @@ func TestOnPayloadAttributes(t *testing.T) {
 
 	require.Equal(t, expectedExecutionPayload, *testRelay.submittedMsg.ExecutionPayload)
 
-	expectedSignature, err := utils.HexToSignature("0xad09f171b1da05636acfc86778c319af69e39c79515d44bdfed616ba2ef677ffd4d155d87b3363c6bae651ce1e92786216b75f1ac91dd65f3b1d1902bf8485e742170732dd82ffdf4decb0151eeb7926dd053efa9794b2ebed1a203e62bb13e9")
+	expectedSignature, err := utils.HexToSignature("0x8d1dc346d469b0678ee72baa559315433af0966d2d05dad0de9ce60ff5e4954d4e28a85643496df279494d105bc4a771034fefcdd83d71df5f1b81c9369942b20d6d574b544a93588f6182ba8b09585eb1cf3e1b6551ccbd9e76a4db8eb579fe")
 
 	require.NoError(t, err)
 	require.Equal(t, expectedSignature, testRelay.submittedMsg.Signature)
@@ -150,7 +160,7 @@ func TestOnPayloadAttributes(t *testing.T) {
 
 	// Change the hash, expect to get the block
 	testExecutableData.ExtraData = hexutil.MustDecode("0x0042fafd")
-	testExecutableData.BlockHash = common.HexToHash("0x0579b1aaca5c079c91e5774bac72c7f9bc2ddf2b126e9c632be68a1cb8f3fc71")
+	testExecutableData.BlockHash = common.HexToHash("0x6a259b9a148da3cc0bf139eaa89292fa9f7b136cfeddad17f7cb0ae33e0c3df9")
 	testBlock, err = engine.ExecutableDataToBlock(*testExecutableData)
 	testEthService.testBlockValue = big.NewInt(10)
 	require.NoError(t, err)

builder/local_relay_test.go

@@ -10,6 +10,8 @@ import (
 	"testing"
 	"time"
 
+	"github.com/ethereum/go-ethereum/core"
+
 	"github.com/attestantio/go-builder-client/api"
 	bellatrixapi "github.com/attestantio/go-builder-client/api/bellatrix"
 	apiv1 "github.com/attestantio/go-builder-client/api/v1"
@@ -30,6 +32,10 @@ import (
 	"golang.org/x/time/rate"
 )
 
+const (
+	testLocalRelayValidatorGasLimit = 15_000_000
+)
+
 func newTestBackend(t *testing.T, forkchoiceData *engine.ExecutableData, block *types.Block, blockValue *big.Int) (*Builder, *LocalRelay, *ValidatorPrivateData) {
 	validator := NewRandomValidator()
 	sk, _ := bls.GenerateRandomSecretKey()
@@ -109,7 +115,7 @@ func prepareRegistrationMessage(t *testing.T, domain phase0.Domain, v *Validator
 
 	msg := apiv1.ValidatorRegistration{
 		FeeRecipient: bellatrix.ExecutionAddress{0x42},
-		GasLimit:     15_000_000,
+		GasLimit:     testLocalRelayValidatorGasLimit,
 		Timestamp:    time.Now(),
 		Pubkey:       pubkey,
 	}
@@ -139,9 +145,10 @@ func TestGetHeader(t *testing.T) {
 		ParentHash:    common.HexToHash("0xafafafa"),
 		FeeRecipient:  common.Address{0x01},
 		LogsBloom:     types.Bloom{0x00, 0x05, 0x10}.Bytes(),
-		BlockHash:     common.HexToHash("0x24e6998e4d2b4fd85f7f0d27ac4b87aaf0ec18e156e4b6e194ab5dadee0cd004"),
+		BlockHash:     common.HexToHash("0x64559c793c74678dff3f5d25aa328526cdb6013f13b6d989d491a8e1d9cac77a"),
 		BaseFeePerGas: big.NewInt(12),
 		ExtraData:     []byte{},
+		GasLimit:      10_000_000,
 	}
 
 	forkchoiceBlock, err := engine.ExecutableDataToBlock(*forkchoiceData)
@@ -164,8 +171,13 @@ func TestGetHeader(t *testing.T) {
 	require.Equal(t, ``, rr.Body.String())
 	require.Equal(t, 204, rr.Code)
 
-	err = backend.OnPayloadAttribute(&types.BuilderPayloadAttributes{})
+	attrs := &types.BuilderPayloadAttributes{}
+	err = backend.OnPayloadAttribute(attrs)
 	require.NoError(t, err)
+
+	expectedGasLimit := core.CalcGasLimit(forkchoiceData.GasLimit, testLocalRelayValidatorGasLimit)
+	require.Equal(t, attrs.GasLimit, expectedGasLimit)
+
 	time.Sleep(2 * time.Second)
 
 	path = fmt.Sprintf("/eth/v1/builder/header/%d/%s/%s", 0, forkchoiceData.ParentHash.Hex(), validator.Pk.String())