Code cleanup (prysmaticlabs#9992)

* Value assigned to a variable is never read before being overwritten

* The result of append is not used anywhere

* Suspicious assignment of range-loop vars detected

* Unused method receiver detected

* Revert "Auxiliary commit to revert individual files from 54edcb4"

This reverts commit bbd1e1beabf7b0c5cfc4f514dcc820062ad6c063.

* Method modifies receiver

* Fix test

* Duplicate imports detected

* Incorrectly formatted error string

* Types of function parameters can be combined

* One more "Unused method receiver detected"

* Unused parameter detected in function

beacon-chain/blockchain/head.go

@@ -244,7 +244,7 @@ func (s *Service) headBlock() block.SignedBeaconBlock {
 // It does a full copy on head state for immutability.
 // This is a lock free version.
 func (s *Service) headState(ctx context.Context) state.BeaconState {
-	ctx, span := trace.StartSpan(ctx, "blockChain.headState")
+	_, span := trace.StartSpan(ctx, "blockChain.headState")
 	defer span.End()
 
 	return s.head.state.Copy()

beacon-chain/blockchain/process_attestation.go

@@ -62,7 +62,7 @@ func (s *Service) onAttestation(ctx context.Context, a *ethpb.Attestation) error
 	genesisTime := baseState.GenesisTime()
 
 	// Verify attestation target is from current epoch or previous epoch.
-	if err := s.verifyAttTargetEpoch(ctx, genesisTime, uint64(time.Now().Unix()), tgt); err != nil {
+	if err := verifyAttTargetEpoch(ctx, genesisTime, uint64(time.Now().Unix()), tgt); err != nil {
 		return err
 	}
 

beacon-chain/blockchain/process_attestation_helpers.go

@@ -61,7 +61,7 @@ func (s *Service) getAttPreState(ctx context.Context, c *ethpb.Checkpoint) (stat
 }
 
 // verifyAttTargetEpoch validates attestation is from the current or previous epoch.
-func (s *Service) verifyAttTargetEpoch(_ context.Context, genesisTime, nowTime uint64, c *ethpb.Checkpoint) error {
+func verifyAttTargetEpoch(_ context.Context, genesisTime, nowTime uint64, c *ethpb.Checkpoint) error {
 	currentSlot := types.Slot((nowTime - genesisTime) / params.BeaconConfig().SecondsPerSlot)
 	currentEpoch := slots.ToEpoch(currentSlot)
 	var prevEpoch types.Epoch

beacon-chain/blockchain/process_attestation_test.go

@@ -266,34 +266,22 @@ func TestStore_UpdateCheckpointState(t *testing.T) {
 func TestAttEpoch_MatchPrevEpoch(t *testing.T) {
 	ctx := context.Background()
 
-	opts := testServiceOptsNoDB()
-	service, err := NewService(ctx, opts...)
-	require.NoError(t, err)
-
 	nowTime := uint64(params.BeaconConfig().SlotsPerEpoch) * params.BeaconConfig().SecondsPerSlot
-	require.NoError(t, service.verifyAttTargetEpoch(ctx, 0, nowTime, &ethpb.Checkpoint{Root: make([]byte, 32)}))
+	require.NoError(t, verifyAttTargetEpoch(ctx, 0, nowTime, &ethpb.Checkpoint{Root: make([]byte, 32)}))
 }
 
 func TestAttEpoch_MatchCurrentEpoch(t *testing.T) {
 	ctx := context.Background()
 
-	opts := testServiceOptsNoDB()
-	service, err := NewService(ctx, opts...)
-	require.NoError(t, err)
-
 	nowTime := uint64(params.BeaconConfig().SlotsPerEpoch) * params.BeaconConfig().SecondsPerSlot
-	require.NoError(t, service.verifyAttTargetEpoch(ctx, 0, nowTime, &ethpb.Checkpoint{Epoch: 1}))
+	require.NoError(t, verifyAttTargetEpoch(ctx, 0, nowTime, &ethpb.Checkpoint{Epoch: 1}))
 }
 
 func TestAttEpoch_NotMatch(t *testing.T) {
 	ctx := context.Background()
 
-	opts := testServiceOptsNoDB()
-	service, err := NewService(ctx, opts...)
-	require.NoError(t, err)
-
 	nowTime := 2 * uint64(params.BeaconConfig().SlotsPerEpoch) * params.BeaconConfig().SecondsPerSlot
-	err = service.verifyAttTargetEpoch(ctx, 0, nowTime, &ethpb.Checkpoint{Root: make([]byte, 32)})
+	err := verifyAttTargetEpoch(ctx, 0, nowTime, &ethpb.Checkpoint{Root: make([]byte, 32)})
 	assert.ErrorContains(t, "target epoch 0 does not match current epoch 2 or prev epoch 1", err)
 }
 

beacon-chain/blockchain/state_balance_cache.go

@@ -28,7 +28,7 @@ type stateByRooter interface {
 // to avoid nil pointer bugs when updating the cache in the read path (get())
 func newStateBalanceCache(sg *stategen.State) (*stateBalanceCache, error) {
 	if sg == nil {
-		return nil, errors.New("Can't initialize state balance cache without stategen")
+		return nil, errors.New("can't initialize state balance cache without stategen")
 	}
 	return &stateBalanceCache{stateGen: sg}, nil
 }

beacon-chain/blockchain/testing/mock.go

@@ -285,12 +285,12 @@ func (s *ChainService) PreviousJustifiedCheckpt() *ethpb.Checkpoint {
 }
 
 // ReceiveAttestation mocks ReceiveAttestation method in chain service.
-func (s *ChainService) ReceiveAttestation(_ context.Context, _ *ethpb.Attestation) error {
+func (_ *ChainService) ReceiveAttestation(_ context.Context, _ *ethpb.Attestation) error {
 	return nil
 }
 
 // ReceiveAttestationNoPubsub mocks ReceiveAttestationNoPubsub method in chain service.
-func (s *ChainService) ReceiveAttestationNoPubsub(context.Context, *ethpb.Attestation) error {
+func (_ *ChainService) ReceiveAttestationNoPubsub(context.Context, *ethpb.Attestation) error {
 	return nil
 }
 
@@ -369,7 +369,7 @@ func (s *ChainService) HasInitSyncBlock(rt [32]byte) bool {
 }
 
 // HeadGenesisValidatorRoot mocks HeadGenesisValidatorRoot method in chain service.
-func (s *ChainService) HeadGenesisValidatorRoot() [32]byte {
+func (_ *ChainService) HeadGenesisValidatorRoot() [32]byte {
 	return [32]byte{}
 }
 
@@ -379,7 +379,7 @@ func (s *ChainService) VerifyBlkDescendant(_ context.Context, _ [32]byte) error
 }
 
 // VerifyLmdFfgConsistency mocks VerifyLmdFfgConsistency and always returns nil.
-func (s *ChainService) VerifyLmdFfgConsistency(_ context.Context, a *ethpb.Attestation) error {
+func (_ *ChainService) VerifyLmdFfgConsistency(_ context.Context, a *ethpb.Attestation) error {
 	if !bytes.Equal(a.Data.BeaconBlockRoot, a.Data.Target.Root) {
 		return errors.New("LMD and FFG miss matched")
 	}
@@ -395,7 +395,7 @@ func (s *ChainService) VerifyFinalizedConsistency(_ context.Context, r []byte) e
 }
 
 // ChainHeads mocks ChainHeads and always return nil.
-func (s *ChainService) ChainHeads() ([][32]byte, []types.Slot) {
+func (_ *ChainService) ChainHeads() ([][32]byte, []types.Slot) {
 	return [][32]byte{
 			bytesutil.ToBytes32(bytesutil.PadTo([]byte("foo"), 32)),
 			bytesutil.ToBytes32(bytesutil.PadTo([]byte("bar"), 32)),
@@ -404,7 +404,7 @@ func (s *ChainService) ChainHeads() ([][32]byte, []types.Slot) {
 }
 
 // HeadPublicKeyToValidatorIndex mocks HeadPublicKeyToValidatorIndex and always return 0 and true.
-func (s *ChainService) HeadPublicKeyToValidatorIndex(_ context.Context, _ [48]byte) (types.ValidatorIndex, bool) {
+func (_ *ChainService) HeadPublicKeyToValidatorIndex(_ context.Context, _ [48]byte) (types.ValidatorIndex, bool) {
 	return 0, true
 }
 

beacon-chain/cache/depositcache/deposits_cache.go

@@ -17,7 +17,6 @@ import (
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/container/trie"
 	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
-	dbpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	"github.com/sirupsen/logrus"
 	"go.opencensus.io/trace"
@@ -50,10 +49,10 @@ type FinalizedDeposits struct {
 // stores all the deposit related data that is required by the beacon-node.
 type DepositCache struct {
 	// Beacon chain deposits in memory.
-	pendingDeposits   []*dbpb.DepositContainer
-	deposits          []*dbpb.DepositContainer
+	pendingDeposits   []*ethpb.DepositContainer
+	deposits          []*ethpb.DepositContainer
 	finalizedDeposits *FinalizedDeposits
-	depositsByKey     map[[48]byte][]*dbpb.DepositContainer
+	depositsByKey     map[[48]byte][]*ethpb.DepositContainer
 	depositsLock      sync.RWMutex
 }
 
@@ -67,8 +66,8 @@ func New() (*DepositCache, error) {
 	// finalizedDeposits.MerkleTrieIndex is initialized to -1 because it represents the index of the last trie item.
 	// Inserting the first item into the trie will set the value of the index to 0.
 	return &DepositCache{
-		pendingDeposits:   []*dbpb.DepositContainer{},
-		deposits:          []*dbpb.DepositContainer{},
+		pendingDeposits:   []*ethpb.DepositContainer{},
+		deposits:          []*ethpb.DepositContainer{},
 		depositsByKey:     map[[48]byte][]*ethpb.DepositContainer{},
 		finalizedDeposits: &FinalizedDeposits{Deposits: finalizedDepositsTrie, MerkleTrieIndex: -1},
 	}, nil
@@ -77,7 +76,7 @@ func New() (*DepositCache, error) {
 // InsertDeposit into the database. If deposit or block number are nil
 // then this method does nothing.
 func (dc *DepositCache) InsertDeposit(ctx context.Context, d *ethpb.Deposit, blockNum uint64, index int64, depositRoot [32]byte) error {
-	ctx, span := trace.StartSpan(ctx, "DepositsCache.InsertDeposit")
+	_, span := trace.StartSpan(ctx, "DepositsCache.InsertDeposit")
 	defer span.End()
 	if d == nil {
 		log.WithFields(logrus.Fields{
@@ -96,9 +95,9 @@ func (dc *DepositCache) InsertDeposit(ctx context.Context, d *ethpb.Deposit, blo
 	}
 	// Keep the slice sorted on insertion in order to avoid costly sorting on retrieval.
 	heightIdx := sort.Search(len(dc.deposits), func(i int) bool { return dc.deposits[i].Index >= index })
-	depCtr := &dbpb.DepositContainer{Deposit: d, Eth1BlockHeight: blockNum, DepositRoot: depositRoot[:], Index: index}
+	depCtr := &ethpb.DepositContainer{Deposit: d, Eth1BlockHeight: blockNum, DepositRoot: depositRoot[:], Index: index}
 	newDeposits := append(
-		[]*dbpb.DepositContainer{depCtr},
+		[]*ethpb.DepositContainer{depCtr},
 		dc.deposits[heightIdx:]...)
 	dc.deposits = append(dc.deposits[:heightIdx], newDeposits...)
 	// Append the deposit to our map, in the event no deposits
@@ -110,8 +109,8 @@ func (dc *DepositCache) InsertDeposit(ctx context.Context, d *ethpb.Deposit, blo
 }
 
 // InsertDepositContainers inserts a set of deposit containers into our deposit cache.
-func (dc *DepositCache) InsertDepositContainers(ctx context.Context, ctrs []*dbpb.DepositContainer) {
-	ctx, span := trace.StartSpan(ctx, "DepositsCache.InsertDepositContainers")
+func (dc *DepositCache) InsertDepositContainers(ctx context.Context, ctrs []*ethpb.DepositContainer) {
+	_, span := trace.StartSpan(ctx, "DepositsCache.InsertDepositContainers")
 	defer span.End()
 	dc.depositsLock.Lock()
 	defer dc.depositsLock.Unlock()
@@ -130,7 +129,7 @@ func (dc *DepositCache) InsertDepositContainers(ctx context.Context, ctrs []*dbp
 
 // InsertFinalizedDeposits inserts deposits up to eth1DepositIndex (inclusive) into the finalized deposits cache.
 func (dc *DepositCache) InsertFinalizedDeposits(ctx context.Context, eth1DepositIndex int64) {
-	ctx, span := trace.StartSpan(ctx, "DepositsCache.InsertFinalizedDeposits")
+	_, span := trace.StartSpan(ctx, "DepositsCache.InsertFinalizedDeposits")
 	defer span.End()
 	dc.depositsLock.Lock()
 	defer dc.depositsLock.Unlock()
@@ -163,8 +162,8 @@ func (dc *DepositCache) InsertFinalizedDeposits(ctx context.Context, eth1Deposit
 }
 
 // AllDepositContainers returns all historical deposit containers.
-func (dc *DepositCache) AllDepositContainers(ctx context.Context) []*dbpb.DepositContainer {
-	ctx, span := trace.StartSpan(ctx, "DepositsCache.AllDepositContainers")
+func (dc *DepositCache) AllDepositContainers(ctx context.Context) []*ethpb.DepositContainer {
+	_, span := trace.StartSpan(ctx, "DepositsCache.AllDepositContainers")
 	defer span.End()
 	dc.depositsLock.RLock()
 	defer dc.depositsLock.RUnlock()
@@ -175,7 +174,7 @@ func (dc *DepositCache) AllDepositContainers(ctx context.Context) []*dbpb.Deposi
 // AllDeposits returns a list of historical deposits until the given block number
 // (inclusive). If no block is specified then this method returns all historical deposits.
 func (dc *DepositCache) AllDeposits(ctx context.Context, untilBlk *big.Int) []*ethpb.Deposit {
-	ctx, span := trace.StartSpan(ctx, "DepositsCache.AllDeposits")
+	_, span := trace.StartSpan(ctx, "DepositsCache.AllDeposits")
 	defer span.End()
 	dc.depositsLock.RLock()
 	defer dc.depositsLock.RUnlock()
@@ -192,7 +191,7 @@ func (dc *DepositCache) AllDeposits(ctx context.Context, untilBlk *big.Int) []*e
 // DepositsNumberAndRootAtHeight returns number of deposits made up to blockheight and the
 // root that corresponds to the latest deposit at that blockheight.
 func (dc *DepositCache) DepositsNumberAndRootAtHeight(ctx context.Context, blockHeight *big.Int) (uint64, [32]byte) {
-	ctx, span := trace.StartSpan(ctx, "DepositsCache.DepositsNumberAndRootAtHeight")
+	_, span := trace.StartSpan(ctx, "DepositsCache.DepositsNumberAndRootAtHeight")
 	defer span.End()
 	dc.depositsLock.RLock()
 	defer dc.depositsLock.RUnlock()
@@ -208,7 +207,7 @@ func (dc *DepositCache) DepositsNumberAndRootAtHeight(ctx context.Context, block
 // DepositByPubkey looks through historical deposits and finds one which contains
 // a certain public key within its deposit data.
 func (dc *DepositCache) DepositByPubkey(ctx context.Context, pubKey []byte) (*ethpb.Deposit, *big.Int) {
-	ctx, span := trace.StartSpan(ctx, "DepositsCache.DepositByPubkey")
+	_, span := trace.StartSpan(ctx, "DepositsCache.DepositByPubkey")
 	defer span.End()
 	dc.depositsLock.RLock()
 	defer dc.depositsLock.RUnlock()
@@ -229,7 +228,7 @@ func (dc *DepositCache) DepositByPubkey(ctx context.Context, pubKey []byte) (*et
 
 // FinalizedDeposits returns the finalized deposits trie.
 func (dc *DepositCache) FinalizedDeposits(ctx context.Context) *FinalizedDeposits {
-	ctx, span := trace.StartSpan(ctx, "DepositsCache.FinalizedDeposits")
+	_, span := trace.StartSpan(ctx, "DepositsCache.FinalizedDeposits")
 	defer span.End()
 	dc.depositsLock.RLock()
 	defer dc.depositsLock.RUnlock()