Merge branch 'develop' into eas-bug

BUILD.bazel

@@ -197,6 +197,25 @@ nogo(
         "//tools/analyzers/logcapitalization:go_default_library",
         "//tools/analyzers/logruswitherror:go_default_library",
         "//tools/analyzers/maligned:go_default_library",
+        "//tools/analyzers/modernize/any:go_default_library",
+        "//tools/analyzers/modernize/appendclipped:go_default_library",
+        "//tools/analyzers/modernize/bloop:go_default_library",
+        "//tools/analyzers/modernize/fmtappendf:go_default_library",
+        "//tools/analyzers/modernize/forvar:go_default_library",
+        "//tools/analyzers/modernize/mapsloop:go_default_library",
+        "//tools/analyzers/modernize/minmax:go_default_library",
+        #"//tools/analyzers/modernize/newexpr:go_default_library", # Disabled until go 1.26.
+        "//tools/analyzers/modernize/omitzero:go_default_library",
+        "//tools/analyzers/modernize/rangeint:go_default_library",
+        "//tools/analyzers/modernize/reflecttypefor:go_default_library",
+        "//tools/analyzers/modernize/slicescontains:go_default_library",
+        #"//tools/analyzers/modernize/slicesdelete:go_default_library", # Disabled, see https://go.dev/issue/73686
+        "//tools/analyzers/modernize/slicessort:go_default_library",
+        "//tools/analyzers/modernize/stringsbuilder:go_default_library",
+        "//tools/analyzers/modernize/stringscutprefix:go_default_library",
+        "//tools/analyzers/modernize/stringsseq:go_default_library",
+        "//tools/analyzers/modernize/testingcontext:go_default_library",
+        "//tools/analyzers/modernize/waitgroup:go_default_library",
         "//tools/analyzers/nop:go_default_library",
         "//tools/analyzers/nopanic:go_default_library",
         "//tools/analyzers/properpermissions:go_default_library",

WORKSPACE

@@ -205,6 +205,26 @@ prysm_image_deps()
 
 load("@io_bazel_rules_go//go:deps.bzl", "go_register_toolchains", "go_rules_dependencies")
 
+# Override golang.org/x/tools to use v0.38.0 instead of v0.30.0
+# This is necessary as this dependency is required by rules_go and they do not accept dependency
+# update PRs. Instead, they ask downstream projects to override the dependency. To generate the
+# patches or update this dependency again, check out the rules_go repo then run the releaser tool.
+# bazel run //go/tools/releaser -- upgrade-dep -mirror=false org_golang_x_tools
+# Copy the patches and http_archive updates from rules_go here.
+http_archive(
+    name = "org_golang_x_tools",
+    patch_args = ["-p1"],
+    patches = [
+        "//third_party:org_golang_x_tools-deletegopls.patch",
+        "//third_party:org_golang_x_tools-gazelle.patch",
+    ],
+    sha256 = "8509908cd7fc35aa09ff49d8494e4fd25bab9e6239fbf57e0d8344f6bec5802b",
+    strip_prefix = "tools-0.38.0",
+    urls = [
+        "https://github.com/golang/tools/archive/refs/tags/v0.38.0.zip",
+    ],
+)
+
 go_rules_dependencies()
 
 go_register_toolchains(

api/apiutil/header.go

@@ -56,7 +56,7 @@ func ParseAccept(header string) []mediaRange {
 	}
 
 	var out []mediaRange
-	for _, field := range strings.Split(header, ",") {
+	for field := range strings.SplitSeq(header, ",") {
 		if r, ok := parseMediaRange(field); ok {
 			out = append(out, r)
 		}

api/client/builder/client.go

@@ -421,7 +421,7 @@ func (c *Client) RegisterValidator(ctx context.Context, svr []*ethpb.SignedValid
 
 func jsonValidatorRegisterRequest(svr []*ethpb.SignedValidatorRegistrationV1) ([]byte, error) {
 	vs := make([]*structs.SignedValidatorRegistration, len(svr))
-	for i := 0; i < len(svr); i++ {
+	for i := range svr {
 		vs[i] = structs.SignedValidatorRegistrationFromConsensus(svr[i])
 	}
 	body, err := json.Marshal(vs)

api/client/builder/types.go

@@ -121,7 +121,7 @@ func (s *Uint64String) UnmarshalText(t []byte) error {
 
 // MarshalText returns a byte representation of the text from Uint64String.
 func (s Uint64String) MarshalText() ([]byte, error) {
-	return []byte(fmt.Sprintf("%d", s)), nil
+	return fmt.Appendf(nil, "%d", s), nil
 }
 
 // VersionResponse is a JSON representation of a field in the builder API header response.

api/grpc/grpcutils.go

@@ -15,7 +15,7 @@ import (
 func LogRequests(
 	ctx context.Context,
 	method string, req,
-	reply interface{},
+	reply any,
 	cc *grpc.ClientConn,
 	invoker grpc.UnaryInvoker,
 	opts ...grpc.CallOption,

api/server/structs/endpoints_config.go

@@ -14,5 +14,5 @@ type GetForkScheduleResponse struct {
 }
 
 type GetSpecResponse struct {
-	Data interface{} `json:"data"`
+	Data any `json:"data"`
 }

async/abool/abool_test.go

@@ -93,9 +93,9 @@ func TestToggleMultipleTimes(t *testing.T) {
 
 	v := New()
 	pre := !v.IsSet()
-	for i := 0; i < 100; i++ {
+	for i := range 100 {
 		v.SetTo(false)
-		for j := 0; j < i; j++ {
+		for range i {
 			pre = v.Toggle()
 		}
 
@@ -149,7 +149,7 @@ func TestRace(t *testing.T) {
 
 	// Writer
 	go func() {
-		for i := 0; i < repeat; i++ {
+		for range repeat {
 			v.Set()
 			wg.Done()
 		}
@@ -157,7 +157,7 @@ func TestRace(t *testing.T) {
 
 	// Reader
 	go func() {
-		for i := 0; i < repeat; i++ {
+		for range repeat {
 			v.IsSet()
 			wg.Done()
 		}
@@ -165,7 +165,7 @@ func TestRace(t *testing.T) {
 
 	// Writer
 	go func() {
-		for i := 0; i < repeat; i++ {
+		for range repeat {
 			v.UnSet()
 			wg.Done()
 		}
@@ -173,7 +173,7 @@ func TestRace(t *testing.T) {
 
 	// Reader And Writer
 	go func() {
-		for i := 0; i < repeat; i++ {
+		for range repeat {
 			v.Toggle()
 			wg.Done()
 		}
@@ -198,8 +198,8 @@ func ExampleAtomicBool() {
 func BenchmarkMutexRead(b *testing.B) {
 	var m sync.RWMutex
 	var v bool
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+
+	for b.Loop() {
 		m.RLock()
 		_ = v
 		m.RUnlock()
@@ -208,16 +208,16 @@ func BenchmarkMutexRead(b *testing.B) {
 
 func BenchmarkAtomicValueRead(b *testing.B) {
 	var v atomic.Value
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+
+	for b.Loop() {
 		_ = v.Load() != nil
 	}
 }
 
 func BenchmarkAtomicBoolRead(b *testing.B) {
 	v := New()
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+
+	for b.Loop() {
 		_ = v.IsSet()
 	}
 }
@@ -227,8 +227,8 @@ func BenchmarkAtomicBoolRead(b *testing.B) {
 func BenchmarkMutexWrite(b *testing.B) {
 	var m sync.RWMutex
 	var v bool
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+
+	for b.Loop() {
 		m.RLock()
 		v = true
 		m.RUnlock()
@@ -239,16 +239,16 @@ func BenchmarkMutexWrite(b *testing.B) {
 
 func BenchmarkAtomicValueWrite(b *testing.B) {
 	var v atomic.Value
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+
+	for b.Loop() {
 		v.Store(true)
 	}
 }
 
 func BenchmarkAtomicBoolWrite(b *testing.B) {
 	v := New()
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+
+	for b.Loop() {
 		v.Set()
 	}
 }
@@ -258,8 +258,8 @@ func BenchmarkAtomicBoolWrite(b *testing.B) {
 func BenchmarkMutexCAS(b *testing.B) {
 	var m sync.RWMutex
 	var v bool
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+
+	for b.Loop() {
 		m.Lock()
 		if !v {
 			v = true
@@ -270,8 +270,8 @@ func BenchmarkMutexCAS(b *testing.B) {
 
 func BenchmarkAtomicBoolCAS(b *testing.B) {
 	v := New()
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+
+	for b.Loop() {
 		v.SetToIf(false, true)
 	}
 }
@@ -281,8 +281,8 @@ func BenchmarkAtomicBoolCAS(b *testing.B) {
 func BenchmarkMutexToggle(b *testing.B) {
 	var m sync.RWMutex
 	var v bool
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+
+	for b.Loop() {
 		m.Lock()
 		v = !v
 		m.Unlock()
@@ -291,8 +291,8 @@ func BenchmarkMutexToggle(b *testing.B) {
 
 func BenchmarkAtomicBoolToggle(b *testing.B) {
 	v := New()
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+
+	for b.Loop() {
 		v.Toggle()
 	}
 }

async/benchmark_test.go

@@ -21,7 +21,7 @@ const (
 
 func init() {
 	input = make([][]byte, benchmarkElements)
-	for i := 0; i < benchmarkElements; i++ {
+	for i := range benchmarkElements {
 		input[i] = make([]byte, benchmarkElementSize)
 		_, err := rand.Read(input[i])
 		if err != nil {
@@ -35,7 +35,7 @@ func hash(input [][]byte) [][]byte {
 	output := make([][]byte, len(input))
 	for i := range input {
 		copy(output, input)
-		for j := 0; j < benchmarkHashRuns; j++ {
+		for range benchmarkHashRuns {
 			hash := sha256.Sum256(output[i])
 			output[i] = hash[:]
 		}
@@ -44,15 +44,15 @@ func hash(input [][]byte) [][]byte {
 }
 
 func BenchmarkHash(b *testing.B) {
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		hash(input)
 	}
 }
 
 func BenchmarkHashMP(b *testing.B) {
 	output := make([][]byte, len(input))
-	for i := 0; i < b.N; i++ {
-		workerResults, err := async.Scatter(len(input), func(offset int, entries int, _ *sync.RWMutex) (interface{}, error) {
+	for b.Loop() {
+		workerResults, err := async.Scatter(len(input), func(offset int, entries int, _ *sync.RWMutex) (any, error) {
 			return hash(input[offset : offset+entries]), nil
 		})
 		require.NoError(b, err)

async/debounce.go

@@ -7,7 +7,7 @@ import (
 
 // Debounce events fired over a channel by a specified duration, ensuring no events
 // are handled until a certain interval of time has passed.
-func Debounce(ctx context.Context, interval time.Duration, eventsChan <-chan interface{}, handler func(interface{})) {
+func Debounce(ctx context.Context, interval time.Duration, eventsChan <-chan any, handler func(any)) {
 	var timer *time.Timer
 	defer func() {
 		if timer != nil {

async/debounce_test.go

@@ -14,7 +14,7 @@ import (
 )
 
 func TestDebounce_NoEvents(t *testing.T) {
-	eventsChan := make(chan interface{}, 100)
+	eventsChan := make(chan any, 100)
 	ctx, cancel := context.WithCancel(t.Context())
 	interval := time.Second
 	timesHandled := int32(0)
@@ -26,7 +26,7 @@ func TestDebounce_NoEvents(t *testing.T) {
 		})
 	}()
 	go func() {
-		async.Debounce(ctx, interval, eventsChan, func(event interface{}) {
+		async.Debounce(ctx, interval, eventsChan, func(event any) {
 			atomic.AddInt32(&timesHandled, 1)
 		})
 		wg.Done()
@@ -38,7 +38,7 @@ func TestDebounce_NoEvents(t *testing.T) {
 }
 
 func TestDebounce_CtxClosing(t *testing.T) {
-	eventsChan := make(chan interface{}, 100)
+	eventsChan := make(chan any, 100)
 	ctx, cancel := context.WithCancel(t.Context())
 	interval := time.Second
 	timesHandled := int32(0)
@@ -62,7 +62,7 @@ func TestDebounce_CtxClosing(t *testing.T) {
 		})
 	}()
 	go func() {
-		async.Debounce(ctx, interval, eventsChan, func(event interface{}) {
+		async.Debounce(ctx, interval, eventsChan, func(event any) {
 			atomic.AddInt32(&timesHandled, 1)
 		})
 		wg.Done()
@@ -74,14 +74,14 @@ func TestDebounce_CtxClosing(t *testing.T) {
 }
 
 func TestDebounce_SingleHandlerInvocation(t *testing.T) {
-	eventsChan := make(chan interface{}, 100)
+	eventsChan := make(chan any, 100)
 	ctx, cancel := context.WithCancel(t.Context())
 	interval := time.Second
 	timesHandled := int32(0)
-	go async.Debounce(ctx, interval, eventsChan, func(event interface{}) {
+	go async.Debounce(ctx, interval, eventsChan, func(event any) {
 		atomic.AddInt32(&timesHandled, 1)
 	})
-	for i := 0; i < 100; i++ {
+	for range 100 {
 		eventsChan <- struct{}{}
 	}
 	// We should expect 100 rapid fire changes to only have caused
@@ -92,14 +92,14 @@ func TestDebounce_SingleHandlerInvocation(t *testing.T) {
 }
 
 func TestDebounce_MultipleHandlerInvocation(t *testing.T) {
-	eventsChan := make(chan interface{}, 100)
+	eventsChan := make(chan any, 100)
 	ctx, cancel := context.WithCancel(t.Context())
 	interval := time.Second
 	timesHandled := int32(0)
-	go async.Debounce(ctx, interval, eventsChan, func(event interface{}) {
+	go async.Debounce(ctx, interval, eventsChan, func(event any) {
 		atomic.AddInt32(&timesHandled, 1)
 	})
-	for i := 0; i < 100; i++ {
+	for range 100 {
 		eventsChan <- struct{}{}
 	}
 	require.Equal(t, int32(0), atomic.LoadInt32(&timesHandled), "Events must prevent from handler execution")

async/event/example_scope_test.go

@@ -93,9 +93,7 @@ func ExampleSubscriptionScope() {
 	// Run a subscriber in the background.
 	divsub := app.SubscribeResults('/', divs)
 	mulsub := app.SubscribeResults('*', muls)
-	wg.Add(1)
-	go func() {
-		defer wg.Done()
+	wg.Go(func() {
 		defer fmt.Println("subscriber exited")
 		defer divsub.Unsubscribe()
 		defer mulsub.Unsubscribe()
@@ -111,7 +109,7 @@ func ExampleSubscriptionScope() {
 				return
 			}
 		}
-	}()
+	})
 
 	// Interact with the app.
 	app.Calc('/', 22, 11)

async/event/example_subscription_test.go

@@ -26,7 +26,7 @@ func ExampleNewSubscription() {
 	// Create a subscription that sends 10 integers on ch.
 	ch := make(chan int)
 	sub := event.NewSubscription(func(quit <-chan struct{}) error {
-		for i := 0; i < 10; i++ {
+		for i := range 10 {
 			select {
 			case ch <- i:
 			case <-quit:

async/event/interface.go

@@ -3,6 +3,6 @@ package event
 // SubscriberSender is an abstract representation of an *event.Feed
 // to use in describing types that accept or return an *event.Feed.
 type SubscriberSender interface {
-	Subscribe(channel interface{}) Subscription
-	Send(value interface{}) (nsent int)
+	Subscribe(channel any) Subscription
+	Send(value any) (nsent int)
 }

async/event/subscription_test.go

@@ -30,7 +30,7 @@ var errInts = errors.New("error in subscribeInts")
 
 func subscribeInts(max, fail int, c chan<- int) Subscription {
 	return NewSubscription(func(quit <-chan struct{}) error {
-		for i := 0; i < max; i++ {
+		for i := range max {
 			if i >= fail {
 				return errInts
 			}
@@ -50,7 +50,7 @@ func TestNewSubscriptionError(t *testing.T) {
 	channel := make(chan int)
 	sub := subscribeInts(10, 2, channel)
 loop:
-	for want := 0; want < 10; want++ {
+	for want := range 10 {
 		select {
 		case got := <-channel:
 			require.Equal(t, want, got)

async/multilock_test.go

@@ -107,15 +107,13 @@ func TestLockUnlock(_ *testing.T) {
 
 func TestLockUnlock_CleansUnused(t *testing.T) {
 	var wg sync.WaitGroup
-	wg.Add(1)
-	go func() {
+	wg.Go(func() {
 		lock := NewMultilock("dog", "cat", "owl")
 		lock.Lock()
 		assert.Equal(t, 3, len(locks.list))
 		lock.Unlock()
 
-		wg.Done()
-	}()
+	})
 	wg.Wait()
 	// We expect that unlocking completely cleared the locks list
 	// given all 3 lock keys were unused at time of unlock.

async/scatter.go

@@ -9,14 +9,14 @@ import (
 // WorkerResults are the results of a scatter worker.
 type WorkerResults struct {
 	Offset int
-	Extent interface{}
+	Extent any
 }
 
 // Scatter scatters a computation across multiple goroutines.
 // This breaks the task in to a number of chunks and executes those chunks in parallel with the function provided.
 // Results returned are collected and presented as a set of WorkerResults, which can be reassembled by the calling function.
 // Any error that occurs in the workers will be passed back to the calling function.
-func Scatter(inputLen int, sFunc func(int, int, *sync.RWMutex) (interface{}, error)) ([]*WorkerResults, error) {
+func Scatter(inputLen int, sFunc func(int, int, *sync.RWMutex) (any, error)) ([]*WorkerResults, error) {
 	if inputLen <= 0 {
 		return nil, errors.New("input length must be greater than 0")
 	}

async/scatter_test.go

@@ -46,9 +46,9 @@ func TestDouble(t *testing.T) {
 				inValues[i] = i
 			}
 			outValues := make([]int, test.inValues)
-			workerResults, err := async.Scatter(len(inValues), func(offset int, entries int, _ *sync.RWMutex) (interface{}, error) {
+			workerResults, err := async.Scatter(len(inValues), func(offset int, entries int, _ *sync.RWMutex) (any, error) {
 				extent := make([]int, entries)
-				for i := 0; i < entries; i++ {
+				for i := range entries {
 					extent[i] = inValues[offset+i] * 2
 				}
 				return extent, nil
@@ -72,8 +72,8 @@ func TestDouble(t *testing.T) {
 func TestMutex(t *testing.T) {
 	totalRuns := 1048576
 	val := 0
-	_, err := async.Scatter(totalRuns, func(offset int, entries int, mu *sync.RWMutex) (interface{}, error) {
-		for i := 0; i < entries; i++ {
+	_, err := async.Scatter(totalRuns, func(offset int, entries int, mu *sync.RWMutex) (any, error) {
+		for range entries {
 			mu.Lock()
 			val++
 			mu.Unlock()
@@ -90,8 +90,8 @@ func TestMutex(t *testing.T) {
 func TestError(t *testing.T) {
 	totalRuns := 1024
 	val := 0
-	_, err := async.Scatter(totalRuns, func(offset int, entries int, mu *sync.RWMutex) (interface{}, error) {
-		for i := 0; i < entries; i++ {
+	_, err := async.Scatter(totalRuns, func(offset int, entries int, mu *sync.RWMutex) (any, error) {
+		for range entries {
 			mu.Lock()
 			val++
 			if val == 1011 {

beacon-chain/blockchain/kzg/validation_test.go

@@ -70,7 +70,7 @@ func TestVerifyBlobKZGProofBatch(t *testing.T) {
 		commitments := make([][]byte, blobCount)
 		proofs := make([][]byte, blobCount)
 
-		for i := 0; i < blobCount; i++ {
+		for i := range blobCount {
 			blob := random.GetRandBlob(int64(i))
 			commitment, proof, err := GenerateCommitmentAndProof(blob)
 			require.NoError(t, err)
@@ -432,8 +432,8 @@ func TestVerifyCellKZGProofBatchFromBlobData(t *testing.T) {
 		commitments[1] = make([]byte, 32) // Wrong size
 
 		// Add cell proofs for both blobs
-		for i := 0; i < blobCount; i++ {
-			for j := uint64(0); j < numberOfColumns; j++ {
+		for range blobCount {
+			for range numberOfColumns {
 				allCellProofs = append(allCellProofs, make([]byte, 48))
 			}
 		}
@@ -450,7 +450,7 @@ func TestVerifyCellKZGProofBatchFromBlobData(t *testing.T) {
 		commitments := make([][]byte, blobCount)
 		var allCellProofs [][]byte
 
-		for i := 0; i < blobCount; i++ {
+		for i := range blobCount {
 			randBlob := random.GetRandBlob(int64(i))
 			var blob Blob
 			copy(blob[:], randBlob[:])
@@ -461,7 +461,7 @@ func TestVerifyCellKZGProofBatchFromBlobData(t *testing.T) {
 			commitments[i] = commitment[:]
 
 			// Add cell proofs - make some invalid in the second blob
-			for j := uint64(0); j < numberOfColumns; j++ {
+			for j := range numberOfColumns {
 				if i == 1 && j == 64 {
 					// Invalid proof size in middle of second blob's proofs
 					allCellProofs = append(allCellProofs, make([]byte, 20))

beacon-chain/blockchain/process_attestation_helpers.go

@@ -22,10 +22,7 @@ import (
 // The caller of this function must have a lock on forkchoice.
 func (s *Service) getRecentPreState(ctx context.Context, c *ethpb.Checkpoint) state.ReadOnlyBeaconState {
 	headEpoch := slots.ToEpoch(s.HeadSlot())
-	if c.Epoch < headEpoch {
-		return nil
-	}
-	if !s.cfg.ForkChoiceStore.IsCanonical([32]byte(c.Root)) {
+	if c.Epoch < headEpoch || c.Epoch == 0 {
 		return nil
 	}
 	// Only use head state if the head state is compatible with the target checkpoint.
@@ -33,11 +30,11 @@ func (s *Service) getRecentPreState(ctx context.Context, c *ethpb.Checkpoint) st
 	if err != nil {
 		return nil
 	}
-	headDependent, err := s.cfg.ForkChoiceStore.DependentRootForEpoch([32]byte(headRoot), c.Epoch)
+	headDependent, err := s.cfg.ForkChoiceStore.DependentRootForEpoch([32]byte(headRoot), c.Epoch-1)
 	if err != nil {
 		return nil
 	}
-	targetDependent, err := s.cfg.ForkChoiceStore.DependentRootForEpoch([32]byte(c.Root), c.Epoch)
+	targetDependent, err := s.cfg.ForkChoiceStore.DependentRootForEpoch([32]byte(c.Root), c.Epoch-1)
 	if err != nil {
 		return nil
 	}
@@ -53,7 +50,11 @@ func (s *Service) getRecentPreState(ctx context.Context, c *ethpb.Checkpoint) st
 		}
 		return st
 	}
-	// Otherwise we need to advance the head state to the start of the target epoch.
+	// At this point we can only have c.Epoch > headEpoch.
+	if !s.cfg.ForkChoiceStore.IsCanonical([32]byte(c.Root)) {
+		return nil
+	}
+	// Advance the head state to the start of the target epoch.
 	// This point can only be reached if c.Root == headRoot and c.Epoch > headEpoch.
 	slot, err := slots.EpochStart(c.Epoch)
 	if err != nil {

beacon-chain/blockchain/process_attestation_test.go

@@ -181,6 +181,123 @@ func TestService_GetRecentPreState(t *testing.T) {
 	require.NotNil(t, service.getRecentPreState(ctx, &ethpb.Checkpoint{Epoch: 1, Root: ckRoot}))
 }
 
+func TestService_GetRecentPreState_Epoch_0(t *testing.T) {
+	service, _ := minimalTestService(t)
+	ctx := t.Context()
+	require.IsNil(t, service.getRecentPreState(ctx, &ethpb.Checkpoint{}))
+}
+
+func TestService_GetRecentPreState_Old_Checkpoint(t *testing.T) {
+	service, _ := minimalTestService(t)
+	ctx := t.Context()
+	s, err := util.NewBeaconState()
+	require.NoError(t, err)
+	ckRoot := bytesutil.PadTo([]byte{'A'}, fieldparams.RootLength)
+	cp0 := &ethpb.Checkpoint{Epoch: 0, Root: ckRoot}
+	err = s.SetFinalizedCheckpoint(cp0)
+	require.NoError(t, err)
+
+	st, root, err := prepareForkchoiceState(ctx, 33, [32]byte(ckRoot), [32]byte{}, [32]byte{'R'}, cp0, cp0)
+	require.NoError(t, err)
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, root))
+	service.head = &head{
+		root:  [32]byte(ckRoot),
+		state: s,
+		slot:  33,
+	}
+	require.IsNil(t, service.getRecentPreState(ctx, &ethpb.Checkpoint{}))
+}
+
+func TestService_GetRecentPreState_Same_DependentRoots(t *testing.T) {
+	service, _ := minimalTestService(t)
+	ctx := t.Context()
+	s, err := util.NewBeaconState()
+	require.NoError(t, err)
+	ckRoot := bytesutil.PadTo([]byte{'A'}, fieldparams.RootLength)
+	cp0 := &ethpb.Checkpoint{Epoch: 0, Root: ckRoot}
+
+	// Create a fork 31 <-- 32 <--- 64
+	//                 \---------33
+	// With the same dependent root at epoch 0 for a checkpoint at epoch 2
+	st, blk, err := prepareForkchoiceState(ctx, 31, [32]byte(ckRoot), [32]byte{}, [32]byte{}, cp0, cp0)
+	require.NoError(t, err)
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, blk))
+	st, blk, err = prepareForkchoiceState(ctx, 32, [32]byte{'S'}, blk.Root(), [32]byte{}, cp0, cp0)
+	require.NoError(t, err)
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, blk))
+	st, blk, err = prepareForkchoiceState(ctx, 64, [32]byte{'T'}, blk.Root(), [32]byte{}, cp0, cp0)
+	require.NoError(t, err)
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, blk))
+	st, blk, err = prepareForkchoiceState(ctx, 33, [32]byte{'U'}, [32]byte(ckRoot), [32]byte{}, cp0, cp0)
+	require.NoError(t, err)
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, blk))
+	cpRoot := blk.Root()
+
+	service.head = &head{
+		root:  [32]byte{'T'},
+		state: s,
+		slot:  64,
+	}
+	require.NotNil(t, service.getRecentPreState(ctx, &ethpb.Checkpoint{Epoch: 2, Root: cpRoot[:]}))
+}
+
+func TestService_GetRecentPreState_Different_DependentRoots(t *testing.T) {
+	service, _ := minimalTestService(t)
+	ctx := t.Context()
+	s, err := util.NewBeaconState()
+	require.NoError(t, err)
+	ckRoot := bytesutil.PadTo([]byte{'A'}, fieldparams.RootLength)
+	cp0 := &ethpb.Checkpoint{Epoch: 0, Root: ckRoot}
+
+	// Create a fork 30 <-- 31 <-- 32 <--- 64
+	//                 \---------33
+	// With the same dependent root at epoch 0 for a checkpoint at epoch 2
+	st, blk, err := prepareForkchoiceState(ctx, 30, [32]byte(ckRoot), [32]byte{}, [32]byte{}, cp0, cp0)
+	require.NoError(t, err)
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, blk))
+	st, blk, err = prepareForkchoiceState(ctx, 31, [32]byte{'S'}, blk.Root(), [32]byte{}, cp0, cp0)
+	require.NoError(t, err)
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, blk))
+	st, blk, err = prepareForkchoiceState(ctx, 32, [32]byte{'T'}, blk.Root(), [32]byte{}, cp0, cp0)
+	require.NoError(t, err)
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, blk))
+	st, blk, err = prepareForkchoiceState(ctx, 64, [32]byte{'U'}, blk.Root(), [32]byte{}, cp0, cp0)
+	require.NoError(t, err)
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, blk))
+	st, blk, err = prepareForkchoiceState(ctx, 33, [32]byte{'V'}, [32]byte(ckRoot), [32]byte{}, cp0, cp0)
+	require.NoError(t, err)
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, blk))
+	cpRoot := blk.Root()
+
+	service.head = &head{
+		root:  [32]byte{'T'},
+		state: s,
+		slot:  64,
+	}
+	require.IsNil(t, service.getRecentPreState(ctx, &ethpb.Checkpoint{Epoch: 2, Root: cpRoot[:]}))
+}
+
+func TestService_GetRecentPreState_Different(t *testing.T) {
+	service, _ := minimalTestService(t)
+	ctx := t.Context()
+	s, err := util.NewBeaconState()
+	require.NoError(t, err)
+	ckRoot := bytesutil.PadTo([]byte{'A'}, fieldparams.RootLength)
+	cp0 := &ethpb.Checkpoint{Epoch: 0, Root: ckRoot}
+	err = s.SetFinalizedCheckpoint(cp0)
+	require.NoError(t, err)
+
+	st, root, err := prepareForkchoiceState(ctx, 33, [32]byte(ckRoot), [32]byte{}, [32]byte{'R'}, cp0, cp0)
+	require.NoError(t, err)
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, root))
+	service.head = &head{
+		root:  [32]byte(ckRoot),
+		state: s,
+		slot:  33,
+	}
+	require.IsNil(t, service.getRecentPreState(ctx, &ethpb.Checkpoint{}))
+}
+
 func TestService_GetAttPreState_Concurrency(t *testing.T) {
 	service, _ := minimalTestService(t)
 	ctx := t.Context()
@@ -209,16 +326,14 @@ func TestService_GetAttPreState_Concurrency(t *testing.T) {
 	var wg sync.WaitGroup
 	errChan := make(chan error, 1000)
 
-	for i := 0; i < 1000; i++ {
-		wg.Add(1)
-		go func() {
-			defer wg.Done()
+	for range 1000 {
+		wg.Go(func() {
 			cp1 := &ethpb.Checkpoint{Epoch: 1, Root: ckRoot}
 			_, err := service.getAttPreState(ctx, cp1)
 			if err != nil {
 				errChan <- err
 			}
-		}()
+		})
 	}
 
 	go func() {

beacon-chain/blockchain/process_block.go

@@ -134,7 +134,7 @@ func getStateVersionAndPayload(st state.BeaconState) (int, interfaces.ExecutionD
 	return preStateVersion, preStateHeader, nil
 }
 
-func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlock, avs das.AvailabilityStore) error {
+func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlock, avs das.AvailabilityChecker) error {
 	ctx, span := trace.StartSpan(ctx, "blockChain.onBlockBatch")
 	defer span.End()
 
@@ -306,7 +306,7 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlo
 	return s.saveHeadNoDB(ctx, lastB, lastBR, preState, !isValidPayload)
 }
 
-func (s *Service) areSidecarsAvailable(ctx context.Context, avs das.AvailabilityStore, roBlock consensusblocks.ROBlock) error {
+func (s *Service) areSidecarsAvailable(ctx context.Context, avs das.AvailabilityChecker, roBlock consensusblocks.ROBlock) error {
 	blockVersion := roBlock.Version()
 	block := roBlock.Block()
 	slot := block.Slot()
@@ -634,9 +634,7 @@ func missingDataColumnIndices(store *filesystem.DataColumnStorage, root [fieldpa
 		return nil, nil
 	}
 
-	numberOfColumns := params.BeaconConfig().NumberOfColumns
-
-	if uint64(len(expected)) > numberOfColumns {
+	if len(expected) > fieldparams.NumberOfColumns {
 		return nil, errMaxDataColumnsExceeded
 	}
 
@@ -817,11 +815,10 @@ func (s *Service) areDataColumnsAvailable(
 			}
 
 		case <-ctx.Done():
-			var missingIndices interface{} = "all"
-			numberOfColumns := params.BeaconConfig().NumberOfColumns
-			missingIndicesCount := uint64(len(missing))
+			var missingIndices any = "all"
+			missingIndicesCount := len(missing)
 
-			if missingIndicesCount < numberOfColumns {
+			if missingIndicesCount < fieldparams.NumberOfColumns {
 				missingIndices = helpers.SortedPrettySliceFromMap(missing)
 			}
 
@@ -948,13 +945,6 @@ func (s *Service) lateBlockTasks(ctx context.Context) {
 	attribute := s.getPayloadAttribute(ctx, headState, s.CurrentSlot()+1, headRoot[:])
 	// return early if we are not proposing next slot
 	if attribute.IsEmpty() {
-		headBlock, err := s.headBlock()
-		if err != nil {
-			log.WithError(err).WithField("head_root", headRoot).Error("Unable to retrieve head block to fire payload attributes event")
-		}
-		// notifyForkchoiceUpdate fires the payload attribute event. But in this case, we won't
-		// call notifyForkchoiceUpdate, so the event is fired here.
-		go s.firePayloadAttributesEvent(s.cfg.StateNotifier.StateFeed(), headBlock, headRoot, s.CurrentSlot()+1)
 		return
 	}
 

beacon-chain/blockchain/process_block_test.go

@@ -147,7 +147,7 @@ func TestStore_OnBlockBatch(t *testing.T) {
 	bState := st.Copy()
 
 	var blks []consensusblocks.ROBlock
-	for i := 0; i < 97; i++ {
+	for i := range 97 {
 		b, err := util.GenerateFullBlock(bState, keys, util.DefaultBlockGenConfig(), primitives.Slot(i))
 		require.NoError(t, err)
 		wsb, err := consensusblocks.NewSignedBeaconBlock(b)
@@ -1323,7 +1323,7 @@ func TestOnBlock_ProcessBlocksParallel(t *testing.T) {
 	require.NoError(t, err)
 
 	logHook := logTest.NewGlobal()
-	for i := 0; i < 10; i++ {
+	for range 10 {
 		fc := &ethpb.Checkpoint{}
 		st, blkRoot, err := prepareForkchoiceState(ctx, 0, wsb1.Block().ParentRoot(), [32]byte{}, [32]byte{}, fc, fc)
 		require.NoError(t, err)
@@ -1949,7 +1949,7 @@ func TestStore_NoViableHead_Liveness(t *testing.T) {
 	require.Equal(t, true, optimistic)
 
 	// Check that the invalid blocks are not in database
-	for i := 0; i < 19-13; i++ {
+	for i := range 19 - 13 {
 		require.Equal(t, false, service.cfg.BeaconDB.HasBlock(ctx, invalidRoots[i]))
 	}
 
@@ -2495,7 +2495,8 @@ func TestMissingBlobIndices(t *testing.T) {
 }
 
 func TestMissingDataColumnIndices(t *testing.T) {
-	countPlusOne := params.BeaconConfig().NumberOfColumns + 1
+	const countPlusOne = fieldparams.NumberOfColumns + 1
+
 	tooManyColumns := make(map[uint64]bool, countPlusOne)
 	for i := range countPlusOne {
 		tooManyColumns[uint64(i)] = true
@@ -2805,6 +2806,10 @@ func TestProcessLightClientUpdate(t *testing.T) {
 	require.NoError(t, s.cfg.BeaconDB.SaveHeadBlockRoot(ctx, [32]byte{1, 2}))
 
 	for _, testVersion := range version.All()[1:] {
+		if testVersion == version.Gloas {
+			// TODO(16027): Unskip light client tests for Gloas
+			continue
+		}
 		t.Run(version.String(testVersion), func(t *testing.T) {
 			l := util.NewTestLightClient(t, testVersion)
 
@@ -2879,7 +2884,7 @@ func TestProcessLightClientUpdate(t *testing.T) {
 
 				// set a better sync aggregate
 				scb := make([]byte, 64)
-				for i := 0; i < 5; i++ {
+				for i := range 5 {
 					scb[i] = 0x01
 				}
 				oldUpdate.SetSyncAggregate(&ethpb.SyncAggregate{

beacon-chain/blockchain/receive_block.go

@@ -39,8 +39,8 @@ var epochsSinceFinalityExpandCache = primitives.Epoch(4)
 
 // BlockReceiver interface defines the methods of chain service for receiving and processing new blocks.
 type BlockReceiver interface {
-	ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte, avs das.AvailabilityStore) error
-	ReceiveBlockBatch(ctx context.Context, blocks []blocks.ROBlock, avs das.AvailabilityStore) error
+	ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte, avs das.AvailabilityChecker) error
+	ReceiveBlockBatch(ctx context.Context, blocks []blocks.ROBlock, avs das.AvailabilityChecker) error
 	HasBlock(ctx context.Context, root [32]byte) bool
 	RecentBlockSlot(root [32]byte) (primitives.Slot, error)
 	BlockBeingSynced([32]byte) bool
@@ -69,7 +69,7 @@ type SlashingReceiver interface {
 //  1. Validate block, apply state transition and update checkpoints
 //  2. Apply fork choice to the processed block
 //  3. Save latest head info
-func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte, avs das.AvailabilityStore) error {
+func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte, avs das.AvailabilityChecker) error {
 	ctx, span := trace.StartSpan(ctx, "blockChain.ReceiveBlock")
 	defer span.End()
 	// Return early if the block is blacklisted
@@ -242,7 +242,7 @@ func (s *Service) validateExecutionAndConsensus(
 	return postState, isValidPayload, nil
 }
 
-func (s *Service) handleDA(ctx context.Context, avs das.AvailabilityStore, block blocks.ROBlock) (time.Duration, error) {
+func (s *Service) handleDA(ctx context.Context, avs das.AvailabilityChecker, block blocks.ROBlock) (time.Duration, error) {
 	var err error
 	start := time.Now()
 	if avs != nil {
@@ -332,7 +332,7 @@ func (s *Service) executePostFinalizationTasks(ctx context.Context, finalizedSta
 // ReceiveBlockBatch processes the whole block batch at once, assuming the block batch is linear ,transitioning
 // the state, performing batch verification of all collected signatures and then performing the appropriate
 // actions for a block post-transition.
-func (s *Service) ReceiveBlockBatch(ctx context.Context, blocks []blocks.ROBlock, avs das.AvailabilityStore) error {
+func (s *Service) ReceiveBlockBatch(ctx context.Context, blocks []blocks.ROBlock, avs das.AvailabilityChecker) error {
 	ctx, span := trace.StartSpan(ctx, "blockChain.ReceiveBlockBatch")
 	defer span.End()
 

beacon-chain/blockchain/receive_block_test.go

@@ -216,13 +216,11 @@ func TestService_ReceiveBlockUpdateHead(t *testing.T) {
 	root, err := b.Block.HashTreeRoot()
 	require.NoError(t, err)
 	wg := sync.WaitGroup{}
-	wg.Add(1)
-	go func() {
+	wg.Go(func() {
 		wsb, err := blocks.NewSignedBeaconBlock(b)
 		require.NoError(t, err)
 		require.NoError(t, s.ReceiveBlock(ctx, wsb, root, nil))
-		wg.Done()
-	}()
+	})
 	wg.Wait()
 	time.Sleep(100 * time.Millisecond)
 	if recvd := len(s.cfg.StateNotifier.(*blockchainTesting.MockStateNotifier).ReceivedEvents()); recvd < 1 {

beacon-chain/blockchain/service.go

@@ -14,6 +14,7 @@ import (
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/cache"
 	statefeed "github.com/OffchainLabs/prysm/v7/beacon-chain/core/feed/state"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/core/helpers"
+	"github.com/OffchainLabs/prysm/v7/beacon-chain/core/peerdas"
 	coreTime "github.com/OffchainLabs/prysm/v7/beacon-chain/core/time"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/core/transition"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/db"
@@ -470,30 +471,35 @@ func (s *Service) removeStartupState() {
 // UpdateCustodyInfoInDB updates the custody information in the database.
 // It returns the (potentially updated) custody group count and the earliest available slot.
 func (s *Service) updateCustodyInfoInDB(slot primitives.Slot) (primitives.Slot, uint64, error) {
-	isSubscribedToAllDataSubnets := flags.Get().SubscribeAllDataSubnets
+	isSupernode := flags.Get().Supernode
+	isSemiSupernode := flags.Get().SemiSupernode
 
 	cfg := params.BeaconConfig()
 	custodyRequirement := cfg.CustodyRequirement
 
 	// Check if the node was previously subscribed to all data subnets, and if so,
 	// store the new status accordingly.
-	wasSubscribedToAllDataSubnets, err := s.cfg.BeaconDB.UpdateSubscribedToAllDataSubnets(s.ctx, isSubscribedToAllDataSubnets)
+	wasSupernode, err := s.cfg.BeaconDB.UpdateSubscribedToAllDataSubnets(s.ctx, isSupernode)
 	if err != nil {
-		log.WithError(err).Error("Could not update subscription status to all data subnets")
+		return 0, 0, errors.Wrap(err, "update subscribed to all data subnets")
 	}
 
-	// Warn the user if the node was previously subscribed to all data subnets and is not any more.
-	if wasSubscribedToAllDataSubnets && !isSubscribedToAllDataSubnets {
-		log.Warnf(
-			"Because the flag `--%s` was previously used, the node will still subscribe to all data subnets.",
-			flags.SubscribeAllDataSubnets.Name,
-		)
+	// Compute the target custody group count based on current flag configuration.
+	targetCustodyGroupCount := custodyRequirement
+
+	// Supernode: custody all groups (either currently set or previously enabled)
+	if isSupernode {
+		targetCustodyGroupCount = cfg.NumberOfCustodyGroups
 	}
 
-	// Compute the custody group count.
-	custodyGroupCount := custodyRequirement
-	if isSubscribedToAllDataSubnets {
-		custodyGroupCount = cfg.NumberOfCustodyGroups
+	// Semi-supernode: custody minimum needed for reconstruction, or custody requirement if higher
+	if isSemiSupernode {
+		semiSupernodeCustody, err := peerdas.MinimumCustodyGroupCountToReconstruct()
+		if err != nil {
+			return 0, 0, errors.Wrap(err, "minimum custody group count")
+		}
+
+		targetCustodyGroupCount = max(custodyRequirement, semiSupernodeCustody)
 	}
 
 	// Safely compute the fulu fork slot.
@@ -510,12 +516,23 @@ func (s *Service) updateCustodyInfoInDB(slot primitives.Slot) (primitives.Slot,
 		}
 	}
 
-	earliestAvailableSlot, custodyGroupCount, err := s.cfg.BeaconDB.UpdateCustodyInfo(s.ctx, slot, custodyGroupCount)
+	earliestAvailableSlot, actualCustodyGroupCount, err := s.cfg.BeaconDB.UpdateCustodyInfo(s.ctx, slot, targetCustodyGroupCount)
 	if err != nil {
 		return 0, 0, errors.Wrap(err, "update custody info")
 	}
 
-	return earliestAvailableSlot, custodyGroupCount, nil
+	if isSupernode {
+		log.WithFields(logrus.Fields{
+			"current": actualCustodyGroupCount,
+			"target":  cfg.NumberOfCustodyGroups,
+		}).Info("Supernode mode enabled. Will custody all data columns going forward.")
+	}
+
+	if wasSupernode && !isSupernode {
+		log.Warningf("Because the `--%s` flag was previously used, the node will continue to act as a super node.", flags.Supernode.Name)
+	}
+
+	return earliestAvailableSlot, actualCustodyGroupCount, nil
 }
 
 func spawnCountdownIfPreGenesis(ctx context.Context, genesisTime time.Time, db db.HeadAccessDatabase) {

beacon-chain/blockchain/service_test.go

@@ -412,8 +412,7 @@ func BenchmarkHasBlockDB(b *testing.B) {
 	r, err := blk.Block.HashTreeRoot()
 	require.NoError(b, err)
 
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		require.Equal(b, true, s.cfg.BeaconDB.HasBlock(ctx, r), "Block is not in DB")
 	}
 }
@@ -432,8 +431,7 @@ func BenchmarkHasBlockForkChoiceStore_DoublyLinkedTree(b *testing.B) {
 	require.NoError(b, err)
 	require.NoError(b, s.cfg.ForkChoiceStore.InsertNode(ctx, beaconState, roblock))
 
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		require.Equal(b, true, s.cfg.ForkChoiceStore.HasNode(r), "Block is not in fork choice store")
 	}
 }
@@ -605,7 +603,6 @@ func TestUpdateCustodyInfoInDB(t *testing.T) {
 		custodyRequirement    = uint64(4)
 		earliestStoredSlot    = primitives.Slot(12)
 		numberOfCustodyGroups = uint64(64)
-		numberOfColumns       = uint64(128)
 	)
 
 	params.SetupTestConfigCleanup(t)
@@ -613,7 +610,6 @@ func TestUpdateCustodyInfoInDB(t *testing.T) {
 	cfg.FuluForkEpoch = fuluForkEpoch
 	cfg.CustodyRequirement = custodyRequirement
 	cfg.NumberOfCustodyGroups = numberOfCustodyGroups
-	cfg.NumberOfColumns = numberOfColumns
 	params.OverrideBeaconConfig(cfg)
 
 	ctx := t.Context()
@@ -644,7 +640,7 @@ func TestUpdateCustodyInfoInDB(t *testing.T) {
 
 		resetFlags := flags.Get()
 		gFlags := new(flags.GlobalFlags)
-		gFlags.SubscribeAllDataSubnets = true
+		gFlags.Supernode = true
 		flags.Init(gFlags)
 		defer flags.Init(resetFlags)
 
@@ -682,7 +678,7 @@ func TestUpdateCustodyInfoInDB(t *testing.T) {
 		// ----------
 		resetFlags := flags.Get()
 		gFlags := new(flags.GlobalFlags)
-		gFlags.SubscribeAllDataSubnets = true
+		gFlags.Supernode = true
 		flags.Init(gFlags)
 		defer flags.Init(resetFlags)
 
@@ -697,4 +693,121 @@ func TestUpdateCustodyInfoInDB(t *testing.T) {
 		require.Equal(t, slot, actualEas)
 		require.Equal(t, numberOfCustodyGroups, actualCgc)
 	})
+
+	t.Run("Supernode downgrade prevented", func(t *testing.T) {
+		service, requirements := minimalTestService(t)
+		err = requirements.db.SaveBlock(ctx, roBlock)
+		require.NoError(t, err)
+
+		// Enable supernode
+		resetFlags := flags.Get()
+		gFlags := new(flags.GlobalFlags)
+		gFlags.Supernode = true
+		flags.Init(gFlags)
+
+		slot := fuluForkEpoch*primitives.Slot(cfg.SlotsPerEpoch) + 1
+		actualEas, actualCgc, err := service.updateCustodyInfoInDB(slot)
+		require.NoError(t, err)
+		require.Equal(t, slot, actualEas)
+		require.Equal(t, numberOfCustodyGroups, actualCgc)
+
+		// Try to downgrade by removing flag
+		gFlags.Supernode = false
+		flags.Init(gFlags)
+		defer flags.Init(resetFlags)
+
+		// Should still be supernode
+		actualEas, actualCgc, err = service.updateCustodyInfoInDB(slot + 2)
+		require.NoError(t, err)
+		require.Equal(t, slot, actualEas)
+		require.Equal(t, numberOfCustodyGroups, actualCgc) // Still 64, not downgraded
+	})
+
+	t.Run("Semi-supernode downgrade prevented", func(t *testing.T) {
+		service, requirements := minimalTestService(t)
+		err = requirements.db.SaveBlock(ctx, roBlock)
+		require.NoError(t, err)
+
+		// Enable semi-supernode
+		resetFlags := flags.Get()
+		gFlags := new(flags.GlobalFlags)
+		gFlags.SemiSupernode = true
+		flags.Init(gFlags)
+
+		slot := fuluForkEpoch*primitives.Slot(cfg.SlotsPerEpoch) + 1
+		actualEas, actualCgc, err := service.updateCustodyInfoInDB(slot)
+		require.NoError(t, err)
+		require.Equal(t, slot, actualEas)
+		semiSupernodeCustody := numberOfCustodyGroups / 2 // 64
+		require.Equal(t, semiSupernodeCustody, actualCgc) // Semi-supernode custodies 64 groups
+
+		// Try to downgrade by removing flag
+		gFlags.SemiSupernode = false
+		flags.Init(gFlags)
+		defer flags.Init(resetFlags)
+
+		// UpdateCustodyInfo should prevent downgrade - custody count should remain at 64
+		actualEas, actualCgc, err = service.updateCustodyInfoInDB(slot + 2)
+		require.NoError(t, err)
+		require.Equal(t, slot, actualEas)
+		require.Equal(t, semiSupernodeCustody, actualCgc) // Still 64 due to downgrade prevention by UpdateCustodyInfo
+	})
+
+	t.Run("Semi-supernode to supernode upgrade allowed", func(t *testing.T) {
+		service, requirements := minimalTestService(t)
+		err = requirements.db.SaveBlock(ctx, roBlock)
+		require.NoError(t, err)
+
+		// Start with semi-supernode
+		resetFlags := flags.Get()
+		gFlags := new(flags.GlobalFlags)
+		gFlags.SemiSupernode = true
+		flags.Init(gFlags)
+
+		slot := fuluForkEpoch*primitives.Slot(cfg.SlotsPerEpoch) + 1
+		actualEas, actualCgc, err := service.updateCustodyInfoInDB(slot)
+		require.NoError(t, err)
+		require.Equal(t, slot, actualEas)
+		semiSupernodeCustody := numberOfCustodyGroups / 2 // 64
+		require.Equal(t, semiSupernodeCustody, actualCgc) // Semi-supernode custodies 64 groups
+
+		// Upgrade to full supernode
+		gFlags.SemiSupernode = false
+		gFlags.Supernode = true
+		flags.Init(gFlags)
+		defer flags.Init(resetFlags)
+
+		// Should upgrade to full supernode
+		upgradeSlot := slot + 2
+		actualEas, actualCgc, err = service.updateCustodyInfoInDB(upgradeSlot)
+		require.NoError(t, err)
+		require.Equal(t, upgradeSlot, actualEas)           // Earliest slot updates when upgrading
+		require.Equal(t, numberOfCustodyGroups, actualCgc) // Upgraded to 128
+	})
+
+	t.Run("Semi-supernode with high validator requirements uses higher custody", func(t *testing.T) {
+		service, requirements := minimalTestService(t)
+		err = requirements.db.SaveBlock(ctx, roBlock)
+		require.NoError(t, err)
+
+		// Enable semi-supernode
+		resetFlags := flags.Get()
+		gFlags := new(flags.GlobalFlags)
+		gFlags.SemiSupernode = true
+		flags.Init(gFlags)
+		defer flags.Init(resetFlags)
+
+		// Mock a high custody requirement (simulating many validators)
+		// We need to override the custody requirement calculation
+		// For this test, we'll verify the logic by checking if custodyRequirement > 64
+		// Since custodyRequirement in minimalTestService is 4, we can't test the high case here
+		// This would require a different test setup with actual validators
+		slot := fuluForkEpoch*primitives.Slot(cfg.SlotsPerEpoch) + 1
+		actualEas, actualCgc, err := service.updateCustodyInfoInDB(slot)
+		require.NoError(t, err)
+		require.Equal(t, slot, actualEas)
+		semiSupernodeCustody := numberOfCustodyGroups / 2 // 64
+		// With low validator requirements (4), should use semi-supernode minimum (64)
+		require.Equal(t, semiSupernodeCustody, actualCgc)
+	})
 }

beacon-chain/blockchain/testing/mock.go

@@ -106,7 +106,7 @@ type EventFeedWrapper struct {
 	subscribed chan struct{} // this channel is closed once a subscription is made
 }
 
-func (w *EventFeedWrapper) Subscribe(channel interface{}) event.Subscription {
+func (w *EventFeedWrapper) Subscribe(channel any) event.Subscription {
 	select {
 	case <-w.subscribed:
 		break // already closed
@@ -116,7 +116,7 @@ func (w *EventFeedWrapper) Subscribe(channel interface{}) event.Subscription {
 	return w.feed.Subscribe(channel)
 }
 
-func (w *EventFeedWrapper) Send(value interface{}) int {
+func (w *EventFeedWrapper) Send(value any) int {
 	return w.feed.Send(value)
 }
 
@@ -275,7 +275,7 @@ func (s *ChainService) ReceiveBlockInitialSync(ctx context.Context, block interf
 }
 
 // ReceiveBlockBatch processes blocks in batches from initial-sync.
-func (s *ChainService) ReceiveBlockBatch(ctx context.Context, blks []blocks.ROBlock, _ das.AvailabilityStore) error {
+func (s *ChainService) ReceiveBlockBatch(ctx context.Context, blks []blocks.ROBlock, _ das.AvailabilityChecker) error {
 	if s.State == nil {
 		return ErrNilState
 	}
@@ -305,7 +305,7 @@ func (s *ChainService) ReceiveBlockBatch(ctx context.Context, blks []blocks.ROBl
 }
 
 // ReceiveBlock mocks ReceiveBlock method in chain service.
-func (s *ChainService) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, _ [32]byte, _ das.AvailabilityStore) error {
+func (s *ChainService) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, _ [32]byte, _ das.AvailabilityChecker) error {
 	if s.ReceiveBlockMockErr != nil {
 		return s.ReceiveBlockMockErr
 	}

beacon-chain/builder/service.go

@@ -166,7 +166,7 @@ func (s *Service) RegisterValidator(ctx context.Context, reg []*ethpb.SignedVali
 	indexToRegistration := make(map[primitives.ValidatorIndex]*ethpb.ValidatorRegistrationV1)
 
 	valid := make([]*ethpb.SignedValidatorRegistrationV1, 0)
-	for i := 0; i < len(reg); i++ {
+	for i := range reg {
 		r := reg[i]
 		nx, exists := s.cfg.headFetcher.HeadPublicKeyToValidatorIndex(bytesutil.ToBytes48(r.Message.Pubkey))
 		if !exists {

beacon-chain/cache/active_balance_test.go

@@ -17,7 +17,7 @@ import (
 
 func TestBalanceCache_AddGetBalance(t *testing.T) {
 	blockRoots := make([][]byte, params.BeaconConfig().SlotsPerHistoricalRoot)
-	for i := 0; i < len(blockRoots); i++ {
+	for i := range blockRoots {
 		b := make([]byte, 8)
 		binary.LittleEndian.PutUint64(b, uint64(i))
 		blockRoots[i] = b
@@ -61,7 +61,7 @@ func TestBalanceCache_AddGetBalance(t *testing.T) {
 
 func TestBalanceCache_BalanceKey(t *testing.T) {
 	blockRoots := make([][]byte, params.BeaconConfig().SlotsPerHistoricalRoot)
-	for i := 0; i < len(blockRoots); i++ {
+	for i := range blockRoots {
 		b := make([]byte, 8)
 		binary.LittleEndian.PutUint64(b, uint64(i))
 		blockRoots[i] = b

beacon-chain/cache/committee.go

@@ -51,7 +51,7 @@ type CommitteeCache struct {
 }
 
 // committeeKeyFn takes the seed as the key to retrieve shuffled indices of a committee in a given epoch.
-func committeeKeyFn(obj interface{}) (string, error) {
+func committeeKeyFn(obj any) (string, error) {
 	info, ok := obj.(*Committees)
 	if !ok {
 		return "", ErrNotCommittee

beacon-chain/cache/committee_fuzz_test.go

@@ -14,7 +14,7 @@ func TestCommitteeKeyFuzz_OK(t *testing.T) {
 	fuzzer := fuzz.NewWithSeed(0)
 	c := &Committees{}
 
-	for i := 0; i < 100000; i++ {
+	for range 100000 {
 		fuzzer.Fuzz(c)
 		k, err := committeeKeyFn(c)
 		require.NoError(t, err)
@@ -27,7 +27,7 @@ func TestCommitteeCache_FuzzCommitteesByEpoch(t *testing.T) {
 	fuzzer := fuzz.NewWithSeed(0)
 	c := &Committees{}
 
-	for i := 0; i < 100000; i++ {
+	for range 100000 {
 		fuzzer.Fuzz(c)
 		require.NoError(t, cache.AddCommitteeShuffledList(t.Context(), c))
 		_, err := cache.Committee(t.Context(), 0, c.Seed, 0)
@@ -42,7 +42,7 @@ func TestCommitteeCache_FuzzActiveIndices(t *testing.T) {
 	fuzzer := fuzz.NewWithSeed(0)
 	c := &Committees{}
 
-	for i := 0; i < 100000; i++ {
+	for range 100000 {
 		fuzzer.Fuzz(c)
 		require.NoError(t, cache.AddCommitteeShuffledList(t.Context(), c))
 

beacon-chain/cache/common.go

@@ -17,6 +17,6 @@ func trim(queue *cache.FIFO, maxSize uint64) {
 }
 
 // popProcessNoopFunc is a no-op function that never returns an error.
-func popProcessNoopFunc(_ interface{}, _ bool) error {
+func popProcessNoopFunc(_ any, _ bool) error {
 	return nil
 }

beacon-chain/cache/depositsnapshot/deposit_cache_test.go

@@ -769,7 +769,7 @@ func TestFinalizedDeposits_ReturnsTrieCorrectly(t *testing.T) {
 	}
 
 	var ctrs []*ethpb.DepositContainer
-	for i := 0; i < 2000; i++ {
+	for i := range 2000 {
 		ctrs = append(ctrs, generateCtr(uint64(10+(i/2)), int64(i)))
 	}
 
@@ -948,9 +948,9 @@ func rootCreator(rn byte) []byte {
 func BenchmarkDepositTree_InsertNewImplementation(b *testing.B) {
 	totalDeposits := 10000
 	input := bytesutil.ToBytes32([]byte("foo"))
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		dt := NewDepositTree()
-		for j := 0; j < totalDeposits; j++ {
+		for range totalDeposits {
 			err := dt.Insert(input[:], 0)
 			require.NoError(b, err)
 		}
@@ -959,10 +959,10 @@ func BenchmarkDepositTree_InsertNewImplementation(b *testing.B) {
 func BenchmarkDepositTree_InsertOldImplementation(b *testing.B) {
 	totalDeposits := 10000
 	input := bytesutil.ToBytes32([]byte("foo"))
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		dt, err := trie.NewTrie(33)
 		require.NoError(b, err)
-		for j := 0; j < totalDeposits; j++ {
+		for range totalDeposits {
 			err := dt.Insert(input[:], 0)
 			require.NoError(b, err)
 		}
@@ -980,8 +980,8 @@ func BenchmarkDepositTree_HashTreeRootNewImplementation(b *testing.B) {
 	}
 
 	b.ReportAllocs()
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+
+	for b.Loop() {
 		_, err = tr.HashTreeRoot()
 		require.NoError(b, err)
 	}
@@ -999,8 +999,8 @@ func BenchmarkDepositTree_HashTreeRootOldImplementation(b *testing.B) {
 	}
 
 	b.ReportAllocs()
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+
+	for b.Loop() {
 		_, err = dt.HashTreeRoot()
 		require.NoError(b, err)
 	}

beacon-chain/cache/depositsnapshot/deposit_tree_snapshot.go

@@ -20,7 +20,7 @@ func (ds *DepositTreeSnapshot) CalculateRoot() ([32]byte, error) {
 	size := ds.depositCount
 	index := len(ds.finalized)
 	root := trie.ZeroHashes[0]
-	for i := 0; i < DepositContractDepth; i++ {
+	for i := range DepositContractDepth {
 		if (size & 1) == 1 {
 			if index == 0 {
 				break

beacon-chain/cache/skip_slot_cache_test.go

@@ -47,15 +47,13 @@ func TestSkipSlotCache_DisabledAndEnabled(t *testing.T) {
 
 	c.Enable()
 	wg := new(sync.WaitGroup)
-	wg.Add(1)
-	go func() {
+	wg.Go(func() {
 		// Get call will only terminate when
 		// it is not longer in progress.
 		obj, err := c.Get(ctx, r)
 		require.NoError(t, err)
 		require.IsNil(t, obj)
-		wg.Done()
-	}()
+	})
 
 	c.MarkNotInProgress(r)
 	wg.Wait()

beacon-chain/cache/sync_committee.go

@@ -236,7 +236,7 @@ func (s *SyncCommitteeCache) UpdatePositionsInCommittee(syncCommitteeBoundaryRoo
 // Given the `syncCommitteeIndexPosition` object, this returns the key of the object.
 // The key is the `currentSyncCommitteeRoot` within the field.
 // Error gets returned if input does not comply with `currentSyncCommitteeRoot` object.
-func keyFn(obj interface{}) (string, error) {
+func keyFn(obj any) (string, error) {
 	info, ok := obj.(*syncCommitteeIndexPosition)
 	if !ok {
 		return "", errNotSyncCommitteeIndexPosition

beacon-chain/cache/sync_subnet_ids_test.go

@@ -12,12 +12,12 @@ import (
 func TestSyncSubnetIDsCache_Roundtrip(t *testing.T) {
 	c := newSyncSubnetIDs()
 
-	for i := 0; i < 20; i++ {
+	for i := range 20 {
 		pubkey := [fieldparams.BLSPubkeyLength]byte{byte(i)}
 		c.AddSyncCommitteeSubnets(pubkey[:], 100, []uint64{uint64(i)}, 0)
 	}
 
-	for i := uint64(0); i < 20; i++ {
+	for i := range uint64(20) {
 		pubkey := [fieldparams.BLSPubkeyLength]byte{byte(i)}
 
 		idxs, _, ok, _ := c.GetSyncCommitteeSubnets(pubkey[:], 100)
@@ -34,7 +34,7 @@ func TestSyncSubnetIDsCache_Roundtrip(t *testing.T) {
 func TestSyncSubnetIDsCache_ValidateCurrentEpoch(t *testing.T) {
 	c := newSyncSubnetIDs()
 
-	for i := 0; i < 20; i++ {
+	for i := range 20 {
 		pubkey := [fieldparams.BLSPubkeyLength]byte{byte(i)}
 		c.AddSyncCommitteeSubnets(pubkey[:], 100, []uint64{uint64(i)}, 0)
 	}
@@ -42,7 +42,7 @@ func TestSyncSubnetIDsCache_ValidateCurrentEpoch(t *testing.T) {
 	coms := c.GetAllSubnets(50)
 	assert.Equal(t, 0, len(coms))
 
-	for i := uint64(0); i < 20; i++ {
+	for i := range uint64(20) {
 		pubkey := [fieldparams.BLSPubkeyLength]byte{byte(i)}
 
 		_, jEpoch, ok, _ := c.GetSyncCommitteeSubnets(pubkey[:], 100)

beacon-chain/core/altair/attestation_test.go

@@ -461,7 +461,7 @@ func TestFuzzProcessAttestationsNoVerify_10000(t *testing.T) {
 	fuzzer := gofuzz.NewWithSeed(0)
 	st := &ethpb.BeaconStateAltair{}
 	b := &ethpb.SignedBeaconBlockAltair{Block: &ethpb.BeaconBlockAltair{}}
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		fuzzer.Fuzz(st)
 		fuzzer.Fuzz(b)
 		if b.Block == nil {

beacon-chain/core/altair/block_test.go

@@ -240,7 +240,7 @@ func TestProcessSyncCommittee_processSyncAggregate(t *testing.T) {
 	proposerIndex, err := helpers.BeaconProposerIndex(t.Context(), beaconState)
 	require.NoError(t, err)
 
-	for i := 0; i < len(syncBits); i++ {
+	for i := range syncBits {
 		if syncBits.BitAt(uint64(i)) {
 			pk := bytesutil.ToBytes48(committeeKeys[i])
 			require.DeepEqual(t, true, votedMap[pk])

beacon-chain/core/altair/deposit.go

@@ -195,10 +195,7 @@ func AddValidatorToRegistry(beaconState state.BeaconState, pubKey []byte, withdr
 //	    withdrawable_epoch=FAR_FUTURE_EPOCH,
 //	)
 func GetValidatorFromDeposit(pubKey []byte, withdrawalCredentials []byte, amount uint64) *ethpb.Validator {
-	effectiveBalance := amount - (amount % params.BeaconConfig().EffectiveBalanceIncrement)
-	if params.BeaconConfig().MaxEffectiveBalance < effectiveBalance {
-		effectiveBalance = params.BeaconConfig().MaxEffectiveBalance
-	}
+	effectiveBalance := min(params.BeaconConfig().MaxEffectiveBalance, amount-(amount%params.BeaconConfig().EffectiveBalanceIncrement))
 
 	return &ethpb.Validator{
 		PublicKey:                  pubKey,

beacon-chain/core/altair/deposit_fuzz_test.go

@@ -16,7 +16,7 @@ func TestFuzzProcessDeposits_10000(t *testing.T) {
 	state := &ethpb.BeaconStateAltair{}
 	deposits := make([]*ethpb.Deposit, 100)
 	ctx := t.Context()
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		fuzzer.Fuzz(state)
 		for i := range deposits {
 			fuzzer.Fuzz(deposits[i])
@@ -37,7 +37,7 @@ func TestFuzzProcessPreGenesisDeposit_10000(t *testing.T) {
 	deposit := &ethpb.Deposit{}
 	ctx := t.Context()
 
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(deposit)
 		s, err := state_native.InitializeFromProtoUnsafeAltair(state)
@@ -56,7 +56,7 @@ func TestFuzzProcessPreGenesisDeposit_Phase0_10000(t *testing.T) {
 	deposit := &ethpb.Deposit{}
 	ctx := t.Context()
 
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(deposit)
 		s, err := state_native.InitializeFromProtoUnsafePhase0(state)
@@ -74,7 +74,7 @@ func TestFuzzProcessDeposit_Phase0_10000(t *testing.T) {
 	state := &ethpb.BeaconState{}
 	deposit := &ethpb.Deposit{}
 
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(deposit)
 		s, err := state_native.InitializeFromProtoUnsafePhase0(state)
@@ -92,7 +92,7 @@ func TestFuzzProcessDeposit_10000(t *testing.T) {
 	state := &ethpb.BeaconStateAltair{}
 	deposit := &ethpb.Deposit{}
 
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(deposit)
 		s, err := state_native.InitializeFromProtoUnsafeAltair(state)

beacon-chain/core/altair/epoch_precompute.go

@@ -122,11 +122,8 @@ func ProcessInactivityScores(
 		}
 
 		if !helpers.IsInInactivityLeak(prevEpoch, finalizedEpoch) {
-			score := recoveryRate
 			// Prevents underflow below 0.
-			if score > v.InactivityScore {
-				score = v.InactivityScore
-			}
+			score := min(recoveryRate, v.InactivityScore)
 			v.InactivityScore -= score
 		}
 		inactivityScores[i] = v.InactivityScore
@@ -242,7 +239,7 @@ func ProcessRewardsAndPenaltiesPrecompute(
 	}
 
 	balances := beaconState.Balances()
-	for i := 0; i < numOfVals; i++ {
+	for i := range numOfVals {
 		vals[i].BeforeEpochTransitionBalance = balances[i]
 
 		// Compute the post balance of the validator after accounting for the

beacon-chain/core/altair/sync_committee_test.go

@@ -21,7 +21,7 @@ import (
 func TestSyncCommitteeIndices_CanGet(t *testing.T) {
 	getState := func(t *testing.T, count uint64, vers int) state.BeaconState {
 		validators := make([]*ethpb.Validator, count)
-		for i := 0; i < len(validators); i++ {
+		for i := range validators {
 			validators[i] = &ethpb.Validator{
 				ExitEpoch:        params.BeaconConfig().FarFutureEpoch,
 				EffectiveBalance: params.BeaconConfig().MinDepositAmount,
@@ -113,7 +113,7 @@ func TestSyncCommitteeIndices_DifferentPeriods(t *testing.T) {
 	helpers.ClearCache()
 	getState := func(t *testing.T, count uint64) state.BeaconState {
 		validators := make([]*ethpb.Validator, count)
-		for i := 0; i < len(validators); i++ {
+		for i := range validators {
 			validators[i] = &ethpb.Validator{
 				ExitEpoch:        params.BeaconConfig().FarFutureEpoch,
 				EffectiveBalance: params.BeaconConfig().MinDepositAmount,
@@ -147,7 +147,7 @@ func TestSyncCommitteeIndices_DifferentPeriods(t *testing.T) {
 func TestSyncCommittee_CanGet(t *testing.T) {
 	getState := func(t *testing.T, count uint64) state.BeaconState {
 		validators := make([]*ethpb.Validator, count)
-		for i := 0; i < len(validators); i++ {
+		for i := range validators {
 			blsKey, err := bls.RandKey()
 			require.NoError(t, err)
 			validators[i] = &ethpb.Validator{
@@ -394,7 +394,7 @@ func Test_ValidateSyncMessageTime(t *testing.T) {
 
 func getState(t *testing.T, count uint64) state.BeaconState {
 	validators := make([]*ethpb.Validator, count)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		blsKey, err := bls.RandKey()
 		require.NoError(t, err)
 		validators[i] = &ethpb.Validator{

beacon-chain/core/altair/upgrade_test.go

@@ -33,7 +33,7 @@ func TestTranslateParticipation(t *testing.T) {
 	r, err := helpers.BlockRootAtSlot(s, 0)
 	require.NoError(t, err)
 	var pendingAtts []*ethpb.PendingAttestation
-	for i := 0; i < 3; i++ {
+	for i := range 3 {
 		pendingAtts = append(pendingAtts, &ethpb.PendingAttestation{
 			Data: &ethpb.AttestationData{
 				CommitteeIndex:  primitives.CommitteeIndex(i),

beacon-chain/core/blocks/attestation.go

@@ -257,7 +257,7 @@ func VerifyIndexedAttestation(ctx context.Context, beaconState state.ReadOnlyBea
 	}
 	indices := indexedAtt.GetAttestingIndices()
 	var pubkeys []bls.PublicKey
-	for i := 0; i < len(indices); i++ {
+	for i := range indices {
 		pubkeyAtIdx := beaconState.PubkeyAtIndex(primitives.ValidatorIndex(indices[i]))
 		pk, err := bls.PublicKeyFromBytes(pubkeyAtIdx[:])
 		if err != nil {

beacon-chain/core/blocks/attestation_test.go

@@ -317,7 +317,7 @@ func TestVerifyAttestationNoVerifySignature_Electra(t *testing.T) {
 func TestConvertToIndexed_OK(t *testing.T) {
 	helpers.ClearCache()
 	validators := make([]*ethpb.Validator, 2*params.BeaconConfig().SlotsPerEpoch)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ExitEpoch: params.BeaconConfig().FarFutureEpoch,
 		}
@@ -373,7 +373,7 @@ func TestVerifyIndexedAttestation_OK(t *testing.T) {
 	validators := make([]*ethpb.Validator, numOfValidators)
 	_, keys, err := util.DeterministicDepositsAndKeys(numOfValidators)
 	require.NoError(t, err)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ExitEpoch:             params.BeaconConfig().FarFutureEpoch,
 			PublicKey:             keys[i].PublicKey().Marshal(),
@@ -481,7 +481,7 @@ func TestValidateIndexedAttestation_BadAttestationsSignatureSet(t *testing.T) {
 	sig := keys[0].Sign([]byte{'t', 'e', 's', 't'})
 	list := bitfield.Bitlist{0b11111}
 	var atts []ethpb.Att
-	for i := uint64(0); i < 1000; i++ {
+	for range uint64(1000) {
 		atts = append(atts, &ethpb.Attestation{
 			Data: &ethpb.AttestationData{
 				CommitteeIndex: 1,
@@ -498,7 +498,7 @@ func TestValidateIndexedAttestation_BadAttestationsSignatureSet(t *testing.T) {
 
 	atts = []ethpb.Att{}
 	list = bitfield.Bitlist{0b10000}
-	for i := uint64(0); i < 1000; i++ {
+	for range uint64(1000) {
 		atts = append(atts, &ethpb.Attestation{
 			Data: &ethpb.AttestationData{
 				CommitteeIndex: 1,
@@ -524,7 +524,7 @@ func TestVerifyAttestations_HandlesPlannedFork(t *testing.T) {
 	validators := make([]*ethpb.Validator, numOfValidators)
 	_, keys, err := util.DeterministicDepositsAndKeys(numOfValidators)
 	require.NoError(t, err)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ExitEpoch:             params.BeaconConfig().FarFutureEpoch,
 			PublicKey:             keys[i].PublicKey().Marshal(),
@@ -588,7 +588,7 @@ func TestRetrieveAttestationSignatureSet_VerifiesMultipleAttestations(t *testing
 	validators := make([]*ethpb.Validator, numOfValidators)
 	_, keys, err := util.DeterministicDepositsAndKeys(numOfValidators)
 	require.NoError(t, err)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ExitEpoch:             params.BeaconConfig().FarFutureEpoch,
 			PublicKey:             keys[i].PublicKey().Marshal(),
@@ -707,7 +707,7 @@ func TestRetrieveAttestationSignatureSet_AcrossFork(t *testing.T) {
 	validators := make([]*ethpb.Validator, numOfValidators)
 	_, keys, err := util.DeterministicDepositsAndKeys(numOfValidators)
 	require.NoError(t, err)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ExitEpoch:             params.BeaconConfig().FarFutureEpoch,
 			PublicKey:             keys[i].PublicKey().Marshal(),

beacon-chain/core/blocks/block_operations_fuzz_test.go

@@ -21,7 +21,7 @@ func TestFuzzProcessAttestationNoVerify_10000(t *testing.T) {
 	state := &ethpb.BeaconState{}
 	att := &ethpb.Attestation{}
 
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(att)
 		s, err := state_native.InitializeFromProtoUnsafePhase0(state)
@@ -37,7 +37,7 @@ func TestFuzzProcessBlockHeader_10000(t *testing.T) {
 	state := &ethpb.BeaconState{}
 	block := &ethpb.SignedBeaconBlock{}
 
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(block)
 
@@ -63,7 +63,7 @@ func TestFuzzverifyDepositDataSigningRoot_10000(_ *testing.T) {
 	var p []byte
 	var s []byte
 	var d []byte
-	for i := 0; i < 10000; i++ {
+	for range 10000 {
 		fuzzer.Fuzz(&ba)
 		fuzzer.Fuzz(&pubkey)
 		fuzzer.Fuzz(&sig)
@@ -83,7 +83,7 @@ func TestFuzzProcessEth1DataInBlock_10000(t *testing.T) {
 	e := &ethpb.Eth1Data{}
 	state, err := state_native.InitializeFromProtoUnsafePhase0(&ethpb.BeaconState{})
 	require.NoError(t, err)
-	for i := 0; i < 10000; i++ {
+	for range 10000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(e)
 		s, err := ProcessEth1DataInBlock(t.Context(), state, e)
@@ -98,7 +98,7 @@ func TestFuzzareEth1DataEqual_10000(_ *testing.T) {
 	eth1data := &ethpb.Eth1Data{}
 	eth1data2 := &ethpb.Eth1Data{}
 
-	for i := 0; i < 10000; i++ {
+	for range 10000 {
 		fuzzer.Fuzz(eth1data)
 		fuzzer.Fuzz(eth1data2)
 		AreEth1DataEqual(eth1data, eth1data2)
@@ -110,7 +110,7 @@ func TestFuzzEth1DataHasEnoughSupport_10000(t *testing.T) {
 	fuzzer := gofuzz.NewWithSeed(0)
 	eth1data := &ethpb.Eth1Data{}
 	var stateVotes []*ethpb.Eth1Data
-	for i := 0; i < 100000; i++ {
+	for i := range 100000 {
 		fuzzer.Fuzz(eth1data)
 		fuzzer.Fuzz(&stateVotes)
 		s, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{
@@ -129,7 +129,7 @@ func TestFuzzProcessBlockHeaderNoVerify_10000(t *testing.T) {
 	state := &ethpb.BeaconState{}
 	block := &ethpb.BeaconBlock{}
 
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(block)
 		s, err := state_native.InitializeFromProtoUnsafePhase0(state)
@@ -145,7 +145,7 @@ func TestFuzzProcessRandao_10000(t *testing.T) {
 	state := &ethpb.BeaconState{}
 	b := &ethpb.SignedBeaconBlock{}
 
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(b)
 		s, err := state_native.InitializeFromProtoUnsafePhase0(state)
@@ -168,7 +168,7 @@ func TestFuzzProcessRandaoNoVerify_10000(t *testing.T) {
 	state := &ethpb.BeaconState{}
 	blockBody := &ethpb.BeaconBlockBody{}
 
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(blockBody)
 		s, err := state_native.InitializeFromProtoUnsafePhase0(state)
@@ -186,7 +186,7 @@ func TestFuzzProcessProposerSlashings_10000(t *testing.T) {
 	state := &ethpb.BeaconState{}
 	p := &ethpb.ProposerSlashing{}
 	ctx := t.Context()
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(p)
 		s, err := state_native.InitializeFromProtoUnsafePhase0(state)
@@ -203,7 +203,7 @@ func TestFuzzVerifyProposerSlashing_10000(t *testing.T) {
 	fuzzer := gofuzz.NewWithSeed(0)
 	state := &ethpb.BeaconState{}
 	proposerSlashing := &ethpb.ProposerSlashing{}
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(proposerSlashing)
 		s, err := state_native.InitializeFromProtoUnsafePhase0(state)
@@ -219,7 +219,7 @@ func TestFuzzProcessAttesterSlashings_10000(t *testing.T) {
 	state := &ethpb.BeaconState{}
 	a := &ethpb.AttesterSlashing{}
 	ctx := t.Context()
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(a)
 		s, err := state_native.InitializeFromProtoUnsafePhase0(state)
@@ -237,7 +237,7 @@ func TestFuzzVerifyAttesterSlashing_10000(t *testing.T) {
 	state := &ethpb.BeaconState{}
 	attesterSlashing := &ethpb.AttesterSlashing{}
 	ctx := t.Context()
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(attesterSlashing)
 		s, err := state_native.InitializeFromProtoUnsafePhase0(state)
@@ -253,7 +253,7 @@ func TestFuzzIsSlashableAttestationData_10000(_ *testing.T) {
 	attestationData := &ethpb.AttestationData{}
 	attestationData2 := &ethpb.AttestationData{}
 
-	for i := 0; i < 10000; i++ {
+	for range 10000 {
 		fuzzer.Fuzz(attestationData)
 		fuzzer.Fuzz(attestationData2)
 		IsSlashableAttestationData(attestationData, attestationData2)
@@ -264,7 +264,7 @@ func TestFuzzslashableAttesterIndices_10000(_ *testing.T) {
 	fuzzer := gofuzz.NewWithSeed(0)
 	attesterSlashing := &ethpb.AttesterSlashing{}
 
-	for i := 0; i < 10000; i++ {
+	for range 10000 {
 		fuzzer.Fuzz(attesterSlashing)
 		SlashableAttesterIndices(attesterSlashing)
 	}
@@ -275,7 +275,7 @@ func TestFuzzProcessAttestationsNoVerify_10000(t *testing.T) {
 	state := &ethpb.BeaconState{}
 	b := &ethpb.SignedBeaconBlock{}
 	ctx := t.Context()
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(b)
 		s, err := state_native.InitializeFromProtoUnsafePhase0(state)
@@ -298,7 +298,7 @@ func TestFuzzVerifyIndexedAttestationn_10000(t *testing.T) {
 	state := &ethpb.BeaconState{}
 	idxAttestation := &ethpb.IndexedAttestation{}
 	ctx := t.Context()
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(idxAttestation)
 		s, err := state_native.InitializeFromProtoUnsafePhase0(state)
@@ -313,7 +313,7 @@ func TestFuzzverifyDeposit_10000(t *testing.T) {
 	fuzzer := gofuzz.NewWithSeed(0)
 	state := &ethpb.BeaconState{}
 	deposit := &ethpb.Deposit{}
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(deposit)
 		s, err := state_native.InitializeFromProtoUnsafePhase0(state)
@@ -329,7 +329,7 @@ func TestFuzzProcessVoluntaryExits_10000(t *testing.T) {
 	state := &ethpb.BeaconState{}
 	e := &ethpb.SignedVoluntaryExit{}
 	ctx := t.Context()
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(e)
 		s, err := state_native.InitializeFromProtoUnsafePhase0(state)
@@ -346,7 +346,7 @@ func TestFuzzProcessVoluntaryExitsNoVerify_10000(t *testing.T) {
 	fuzzer := gofuzz.NewWithSeed(0)
 	state := &ethpb.BeaconState{}
 	e := &ethpb.SignedVoluntaryExit{}
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(e)
 		s, err := state_native.InitializeFromProtoUnsafePhase0(state)
@@ -366,7 +366,7 @@ func TestFuzzVerifyExit_10000(t *testing.T) {
 	fork := &ethpb.Fork{}
 	var slot primitives.Slot
 
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		fuzzer.Fuzz(ve)
 		fuzzer.Fuzz(rawVal)
 		fuzzer.Fuzz(fork)

beacon-chain/core/blocks/eth1_data_test.go

@@ -19,7 +19,7 @@ import (
 
 func FakeDeposits(n uint64) []*ethpb.Eth1Data {
 	deposits := make([]*ethpb.Eth1Data, n)
-	for i := uint64(0); i < n; i++ {
+	for i := range n {
 		deposits[i] = &ethpb.Eth1Data{
 			DepositCount: 1,
 			DepositRoot:  bytesutil.PadTo([]byte("root"), 32),
@@ -175,7 +175,7 @@ func TestProcessEth1Data_SetsCorrectly(t *testing.T) {
 	}
 
 	period := uint64(params.BeaconConfig().SlotsPerEpoch.Mul(uint64(params.BeaconConfig().EpochsPerEth1VotingPeriod)))
-	for i := uint64(0); i < period; i++ {
+	for range period {
 		processedState, err := blocks.ProcessEth1DataInBlock(t.Context(), beaconState, b.Block.Body.Eth1Data)
 		require.NoError(t, err)
 		require.Equal(t, true, processedState.Version() == version.Phase0)

beacon-chain/core/blocks/header_test.go

@@ -27,7 +27,7 @@ func init() {
 
 func TestProcessBlockHeader_ImproperBlockSlot(t *testing.T) {
 	validators := make([]*ethpb.Validator, params.BeaconConfig().MinGenesisActiveValidatorCount)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			PublicKey:             make([]byte, 32),
 			WithdrawalCredentials: make([]byte, 32),
@@ -104,7 +104,7 @@ func TestProcessBlockHeader_WrongProposerSig(t *testing.T) {
 
 func TestProcessBlockHeader_DifferentSlots(t *testing.T) {
 	validators := make([]*ethpb.Validator, params.BeaconConfig().MinGenesisActiveValidatorCount)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			PublicKey:             make([]byte, 32),
 			WithdrawalCredentials: make([]byte, 32),
@@ -148,7 +148,7 @@ func TestProcessBlockHeader_DifferentSlots(t *testing.T) {
 
 func TestProcessBlockHeader_PreviousBlockRootNotSignedRoot(t *testing.T) {
 	validators := make([]*ethpb.Validator, params.BeaconConfig().MinGenesisActiveValidatorCount)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			PublicKey:             make([]byte, 48),
 			WithdrawalCredentials: make([]byte, 32),
@@ -189,7 +189,7 @@ func TestProcessBlockHeader_PreviousBlockRootNotSignedRoot(t *testing.T) {
 
 func TestProcessBlockHeader_SlashedProposer(t *testing.T) {
 	validators := make([]*ethpb.Validator, params.BeaconConfig().MinGenesisActiveValidatorCount)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			PublicKey:             make([]byte, 48),
 			WithdrawalCredentials: make([]byte, 32),
@@ -233,7 +233,7 @@ func TestProcessBlockHeader_SlashedProposer(t *testing.T) {
 
 func TestProcessBlockHeader_OK(t *testing.T) {
 	validators := make([]*ethpb.Validator, params.BeaconConfig().MinGenesisActiveValidatorCount)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			PublicKey:             make([]byte, 32),
 			WithdrawalCredentials: make([]byte, 32),
@@ -293,7 +293,7 @@ func TestProcessBlockHeader_OK(t *testing.T) {
 
 func TestBlockSignatureSet_OK(t *testing.T) {
 	validators := make([]*ethpb.Validator, params.BeaconConfig().MinGenesisActiveValidatorCount)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			PublicKey:             make([]byte, 32),
 			WithdrawalCredentials: make([]byte, 32),

beacon-chain/core/blocks/payload.go

@@ -90,6 +90,9 @@ func IsExecutionEnabled(st state.ReadOnlyBeaconState, body interfaces.ReadOnlyBe
 	if st == nil || body == nil {
 		return false, errors.New("nil state or block body")
 	}
+	if st.Version() >= version.Capella {
+		return true, nil
+	}
 	if IsPreBellatrixVersion(st.Version()) {
 		return false, nil
 	}

beacon-chain/core/blocks/payload_test.go

@@ -260,11 +260,12 @@ func Test_IsExecutionBlockCapella(t *testing.T) {
 
 func Test_IsExecutionEnabled(t *testing.T) {
 	tests := []struct {
-		name        string
-		payload     *enginev1.ExecutionPayload
-		header      interfaces.ExecutionData
-		useAltairSt bool
-		want        bool
+		name         string
+		payload      *enginev1.ExecutionPayload
+		header       interfaces.ExecutionData
+		useAltairSt  bool
+		useCapellaSt bool
+		want         bool
 	}{
 		{
 			name:    "use older than bellatrix state",
@@ -331,6 +332,17 @@ func Test_IsExecutionEnabled(t *testing.T) {
 			}(),
 			want: true,
 		},
+		{
+			name:    "capella state always enabled",
+			payload: emptyPayload(),
+			header: func() interfaces.ExecutionData {
+				h, err := emptyPayloadHeader()
+				require.NoError(t, err)
+				return h
+			}(),
+			useCapellaSt: true,
+			want:         true,
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -342,6 +354,8 @@ func Test_IsExecutionEnabled(t *testing.T) {
 			require.NoError(t, err)
 			if tt.useAltairSt {
 				st, _ = util.DeterministicGenesisStateAltair(t, 1)
+			} else if tt.useCapellaSt {
+				st, _ = util.DeterministicGenesisStateCapella(t, 1)
 			}
 			got, err := blocks.IsExecutionEnabled(st, body)
 			require.NoError(t, err)
@@ -851,8 +865,7 @@ func BenchmarkBellatrixComplete(b *testing.B) {
 	require.NoError(b, err)
 	require.NoError(b, st.SetLatestExecutionPayloadHeader(h))
 
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		_, err := blocks.IsMergeTransitionComplete(st)
 		require.NoError(b, err)
 	}

beacon-chain/core/electra/churn_test.go

@@ -28,7 +28,7 @@ func createValidatorsWithTotalActiveBalance(totalBal primitives.Gwei) []*eth.Val
 			ActivationEpoch:       primitives.Epoch(0),
 			EffectiveBalance:      params.BeaconConfig().MinActivationBalance,
 			ExitEpoch:             params.BeaconConfig().FarFutureEpoch,
-			PublicKey:             []byte(fmt.Sprintf("val_%d", i)),
+			PublicKey:             fmt.Appendf(nil, "val_%d", i),
 			WithdrawableEpoch:     params.BeaconConfig().FarFutureEpoch,
 			WithdrawalCredentials: wd,
 		}

beacon-chain/core/electra/deposit_fuzz_test.go

@@ -16,7 +16,7 @@ func TestFuzzProcessDeposits_10000(t *testing.T) {
 	state := &ethpb.BeaconStateElectra{}
 	deposits := make([]*ethpb.Deposit, 100)
 	ctx := t.Context()
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		fuzzer.Fuzz(state)
 		for i := range deposits {
 			fuzzer.Fuzz(deposits[i])
@@ -36,7 +36,7 @@ func TestFuzzProcessDeposit_10000(t *testing.T) {
 	state := &ethpb.BeaconStateElectra{}
 	deposit := &ethpb.Deposit{}
 
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(deposit)
 		s, err := state_native.InitializeFromProtoUnsafeElectra(state)

beacon-chain/core/electra/deposits_test.go

@@ -95,7 +95,7 @@ func TestProcessPendingDeposits(t *testing.T) {
 				require.NoError(t, err)
 				require.Equal(t, primitives.Gwei(100), res)
 				// Validators 0..9 should have their balance increased
-				for i := primitives.ValidatorIndex(0); i < 10; i++ {
+				for i := range primitives.ValidatorIndex(10) {
 					b, err := st.BalanceAtIndex(i)
 					require.NoError(t, err)
 					require.Equal(t, params.BeaconConfig().MinActivationBalance+uint64(amountAvailForProcessing)/10, b)
@@ -122,7 +122,7 @@ func TestProcessPendingDeposits(t *testing.T) {
 			check: func(t *testing.T, st state.BeaconState) {
 				amountAvailForProcessing := helpers.ActivationExitChurnLimit(1_000 * 1e9)
 				// Validators 0..9 should have their balance increased
-				for i := primitives.ValidatorIndex(0); i < 2; i++ {
+				for i := range primitives.ValidatorIndex(2) {
 					b, err := st.BalanceAtIndex(i)
 					require.NoError(t, err)
 					require.Equal(t, params.BeaconConfig().MinActivationBalance+uint64(amountAvailForProcessing), b)
@@ -149,7 +149,7 @@ func TestProcessPendingDeposits(t *testing.T) {
 				require.NoError(t, err)
 				require.Equal(t, primitives.Gwei(0), res)
 				// Validators 0..4 should have their balance increased
-				for i := primitives.ValidatorIndex(0); i < 4; i++ {
+				for i := range primitives.ValidatorIndex(4) {
 					b, err := st.BalanceAtIndex(i)
 					require.NoError(t, err)
 					require.Equal(t, params.BeaconConfig().MinActivationBalance+uint64(amountAvailForProcessing)/5, b)
@@ -528,7 +528,7 @@ func stateWithActiveBalanceETH(t *testing.T, balETH uint64) state.BeaconState {
 
 	vals := make([]*eth.Validator, numVals)
 	bals := make([]uint64, numVals)
-	for i := uint64(0); i < numVals; i++ {
+	for i := range numVals {
 		wc := make([]byte, 32)
 		wc[0] = params.BeaconConfig().ETH1AddressWithdrawalPrefixByte
 		wc[31] = byte(i)

beacon-chain/core/electra/registry_updates_test.go

@@ -56,7 +56,7 @@ func TestProcessRegistryUpdates(t *testing.T) {
 					Slot:                5 * params.BeaconConfig().SlotsPerEpoch,
 					FinalizedCheckpoint: &eth.Checkpoint{Epoch: finalizedEpoch, Root: make([]byte, fieldparams.RootLength)},
 				}
-				for i := uint64(0); i < 10; i++ {
+				for range uint64(10) {
 					base.Validators = append(base.Validators, &eth.Validator{
 						ActivationEligibilityEpoch: finalizedEpoch,
 						EffectiveBalance:           params.BeaconConfig().MaxEffectiveBalance,
@@ -82,7 +82,7 @@ func TestProcessRegistryUpdates(t *testing.T) {
 					Slot:                5 * params.BeaconConfig().SlotsPerEpoch,
 					FinalizedCheckpoint: &eth.Checkpoint{Epoch: finalizedEpoch, Root: make([]byte, fieldparams.RootLength)},
 				}
-				for i := uint64(0); i < 10; i++ {
+				for range uint64(10) {
 					base.Validators = append(base.Validators, &eth.Validator{
 						EffectiveBalance:  params.BeaconConfig().EjectionBalance - 1,
 						ExitEpoch:         params.BeaconConfig().FarFutureEpoch,
@@ -108,7 +108,7 @@ func TestProcessRegistryUpdates(t *testing.T) {
 					Slot:                5 * params.BeaconConfig().SlotsPerEpoch,
 					FinalizedCheckpoint: &eth.Checkpoint{Epoch: finalizedEpoch, Root: make([]byte, fieldparams.RootLength)},
 				}
-				for i := uint64(0); i < 10; i++ {
+				for range uint64(10) {
 					base.Validators = append(base.Validators, &eth.Validator{
 						EffectiveBalance:  params.BeaconConfig().EjectionBalance - 1,
 						ExitEpoch:         10,
@@ -157,7 +157,7 @@ func Benchmark_ProcessRegistryUpdates_MassEjection(b *testing.B) {
 	st, err := util.NewBeaconStateElectra()
 	require.NoError(b, err)
 
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		b.StopTimer()
 		if err := st.SetValidators(genValidators(100000)); err != nil {
 			panic(err)

beacon-chain/core/epoch/epoch_processing.go

@@ -329,10 +329,7 @@ func ProcessEffectiveBalanceUpdates(st state.BeaconState) (state.BeaconState, er
 		balance := bals[idx]
 
 		if balance+downwardThreshold < val.EffectiveBalance() || val.EffectiveBalance()+upwardThreshold < balance {
-			effectiveBal := maxEffBalance
-			if effectiveBal > balance-balance%effBalanceInc {
-				effectiveBal = balance - balance%effBalanceInc
-			}
+			effectiveBal := min(maxEffBalance, balance-balance%effBalanceInc)
 			if effectiveBal != val.EffectiveBalance() {
 				newVal = val.Copy()
 				newVal.EffectiveBalance = effectiveBal

beacon-chain/core/epoch/epoch_processing_fuzz_test.go

@@ -14,7 +14,7 @@ func TestFuzzFinalUpdates_10000(t *testing.T) {
 	fuzzer := gofuzz.NewWithSeed(0)
 	base := &ethpb.BeaconState{}
 
-	for i := 0; i < 10000; i++ {
+	for i := range 10000 {
 		fuzzer.Fuzz(base)
 		s, err := state_native.InitializeFromProtoUnsafePhase0(base)
 		require.NoError(t, err)

beacon-chain/core/epoch/epoch_processing_test.go

@@ -218,7 +218,7 @@ func TestProcessRegistryUpdates_EligibleToActivate_Cancun(t *testing.T) {
 	cfg.ChurnLimitQuotient = 1
 	params.OverrideBeaconConfig(cfg)
 
-	for i := uint64(0); i < 10; i++ {
+	for range uint64(10) {
 		base.Validators = append(base.Validators, &ethpb.Validator{
 			ActivationEligibilityEpoch: finalizedEpoch,
 			EffectiveBalance:           params.BeaconConfig().MaxEffectiveBalance,
@@ -314,28 +314,28 @@ func TestProcessRegistryUpdates_CanExits(t *testing.T) {
 
 func buildState(t testing.TB, slot primitives.Slot, validatorCount uint64) state.BeaconState {
 	validators := make([]*ethpb.Validator, validatorCount)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ExitEpoch:        params.BeaconConfig().FarFutureEpoch,
 			EffectiveBalance: params.BeaconConfig().MaxEffectiveBalance,
 		}
 	}
 	validatorBalances := make([]uint64, len(validators))
-	for i := 0; i < len(validatorBalances); i++ {
+	for i := range validatorBalances {
 		validatorBalances[i] = params.BeaconConfig().MaxEffectiveBalance
 	}
 	latestActiveIndexRoots := make(
 		[][]byte,
 		params.BeaconConfig().EpochsPerHistoricalVector,
 	)
-	for i := 0; i < len(latestActiveIndexRoots); i++ {
+	for i := range latestActiveIndexRoots {
 		latestActiveIndexRoots[i] = params.BeaconConfig().ZeroHash[:]
 	}
 	latestRandaoMixes := make(
 		[][]byte,
 		params.BeaconConfig().EpochsPerHistoricalVector,
 	)
-	for i := 0; i < len(latestRandaoMixes); i++ {
+	for i := range latestRandaoMixes {
 		latestRandaoMixes[i] = params.BeaconConfig().ZeroHash[:]
 	}
 	s, err := util.NewBeaconState()

beacon-chain/core/epoch/precompute/justification_finalization_test.go

@@ -19,7 +19,7 @@ func TestProcessJustificationAndFinalizationPreCompute_ConsecutiveEpochs(t *test
 	e := params.BeaconConfig().FarFutureEpoch
 	a := params.BeaconConfig().MaxEffectiveBalance
 	blockRoots := make([][]byte, params.BeaconConfig().SlotsPerEpoch*2+1)
-	for i := 0; i < len(blockRoots); i++ {
+	for i := range blockRoots {
 		blockRoots[i] = []byte{byte(i)}
 	}
 	base := &ethpb.BeaconState{
@@ -56,7 +56,7 @@ func TestProcessJustificationAndFinalizationPreCompute_JustifyCurrentEpoch(t *te
 	e := params.BeaconConfig().FarFutureEpoch
 	a := params.BeaconConfig().MaxEffectiveBalance
 	blockRoots := make([][]byte, params.BeaconConfig().SlotsPerEpoch*2+1)
-	for i := 0; i < len(blockRoots); i++ {
+	for i := range blockRoots {
 		blockRoots[i] = []byte{byte(i)}
 	}
 	base := &ethpb.BeaconState{
@@ -93,7 +93,7 @@ func TestProcessJustificationAndFinalizationPreCompute_JustifyPrevEpoch(t *testi
 	e := params.BeaconConfig().FarFutureEpoch
 	a := params.BeaconConfig().MaxEffectiveBalance
 	blockRoots := make([][]byte, params.BeaconConfig().SlotsPerEpoch*2+1)
-	for i := 0; i < len(blockRoots); i++ {
+	for i := range blockRoots {
 		blockRoots[i] = []byte{byte(i)}
 	}
 	base := &ethpb.BeaconState{
@@ -128,7 +128,7 @@ func TestProcessJustificationAndFinalizationPreCompute_JustifyPrevEpoch(t *testi
 func TestUnrealizedCheckpoints(t *testing.T) {
 	validators := make([]*ethpb.Validator, params.BeaconConfig().MinGenesisActiveValidatorCount)
 	balances := make([]uint64, len(validators))
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ExitEpoch:        params.BeaconConfig().FarFutureEpoch,
 			EffectiveBalance: params.BeaconConfig().MaxEffectiveBalance,

beacon-chain/core/epoch/precompute/reward_penalty.go

@@ -42,7 +42,7 @@ func ProcessRewardsAndPenaltiesPrecompute(
 		return nil, errors.Wrap(err, "could not get proposer attestation delta")
 	}
 	validatorBals := state.Balances()
-	for i := 0; i < numOfVals; i++ {
+	for i := range numOfVals {
 		vp[i].BeforeEpochTransitionBalance = validatorBals[i]
 
 		// Compute the post balance of the validator after accounting for the

beacon-chain/core/epoch/precompute/reward_penalty_test.go

@@ -24,7 +24,7 @@ func TestProcessRewardsAndPenaltiesPrecompute(t *testing.T) {
 	validatorCount := uint64(2048)
 	base := buildState(e+3, validatorCount)
 	atts := make([]*ethpb.PendingAttestation, 3)
-	for i := 0; i < len(atts); i++ {
+	for i := range atts {
 		atts[i] = &ethpb.PendingAttestation{
 			Data: &ethpb.AttestationData{
 				Target: &ethpb.Checkpoint{Root: make([]byte, fieldparams.RootLength)},
@@ -63,7 +63,7 @@ func TestAttestationDeltas_ZeroEpoch(t *testing.T) {
 	base := buildState(e+2, validatorCount)
 	atts := make([]*ethpb.PendingAttestation, 3)
 	var emptyRoot [32]byte
-	for i := 0; i < len(atts); i++ {
+	for i := range atts {
 		atts[i] = &ethpb.PendingAttestation{
 			Data: &ethpb.AttestationData{
 				Target: &ethpb.Checkpoint{
@@ -99,7 +99,7 @@ func TestAttestationDeltas_ZeroInclusionDelay(t *testing.T) {
 	base := buildState(e+2, validatorCount)
 	atts := make([]*ethpb.PendingAttestation, 3)
 	var emptyRoot [32]byte
-	for i := 0; i < len(atts); i++ {
+	for i := range atts {
 		atts[i] = &ethpb.PendingAttestation{
 			Data: &ethpb.AttestationData{
 				Target: &ethpb.Checkpoint{
@@ -131,7 +131,7 @@ func TestProcessRewardsAndPenaltiesPrecompute_SlashedInactivePenalty(t *testing.
 	validatorCount := uint64(2048)
 	base := buildState(e+3, validatorCount)
 	atts := make([]*ethpb.PendingAttestation, 3)
-	for i := 0; i < len(atts); i++ {
+	for i := range atts {
 		atts[i] = &ethpb.PendingAttestation{
 			Data: &ethpb.AttestationData{
 				Target: &ethpb.Checkpoint{Root: make([]byte, fieldparams.RootLength)},
@@ -176,28 +176,28 @@ func TestProcessRewardsAndPenaltiesPrecompute_SlashedInactivePenalty(t *testing.
 
 func buildState(slot primitives.Slot, validatorCount uint64) *ethpb.BeaconState {
 	validators := make([]*ethpb.Validator, validatorCount)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ExitEpoch:        params.BeaconConfig().FarFutureEpoch,
 			EffectiveBalance: params.BeaconConfig().MaxEffectiveBalance,
 		}
 	}
 	validatorBalances := make([]uint64, len(validators))
-	for i := 0; i < len(validatorBalances); i++ {
+	for i := range validatorBalances {
 		validatorBalances[i] = params.BeaconConfig().MaxEffectiveBalance
 	}
 	latestActiveIndexRoots := make(
 		[][]byte,
 		params.BeaconConfig().EpochsPerHistoricalVector,
 	)
-	for i := 0; i < len(latestActiveIndexRoots); i++ {
+	for i := range latestActiveIndexRoots {
 		latestActiveIndexRoots[i] = params.BeaconConfig().ZeroHash[:]
 	}
 	latestRandaoMixes := make(
 		[][]byte,
 		params.BeaconConfig().EpochsPerHistoricalVector,
 	)
-	for i := 0; i < len(latestRandaoMixes); i++ {
+	for i := range latestRandaoMixes {
 		latestRandaoMixes[i] = params.BeaconConfig().ZeroHash[:]
 	}
 	return &ethpb.BeaconState{

beacon-chain/core/feed/event.go

@@ -17,5 +17,5 @@ type Event struct {
 	// Type is the type of event.
 	Type EventType
 	// Data is event-specific data.
-	Data interface{}
+	Data any
 }

beacon-chain/core/helpers/attestation_test.go

@@ -54,7 +54,7 @@ func TestAttestation_ComputeSubnetForAttestation(t *testing.T) {
 	validatorCount := committeeCount * params.BeaconConfig().TargetCommitteeSize
 	validators := make([]*ethpb.Validator, validatorCount)
 
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		k := make([]byte, 48)
 		copy(k, strconv.Itoa(i))
 		validators[i] = &ethpb.Validator{

beacon-chain/core/helpers/beacon_committee.go

@@ -5,7 +5,7 @@ package helpers
 import (
 	"context"
 	"fmt"
-	"sort"
+	"slices"
 
 	"github.com/OffchainLabs/go-bitfield"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/cache"
@@ -515,9 +515,7 @@ func UpdateCommitteeCache(ctx context.Context, state state.ReadOnlyBeaconState,
 	// used for failing verify signature fallback.
 	sortedIndices := make([]primitives.ValidatorIndex, len(shuffledIndices))
 	copy(sortedIndices, shuffledIndices)
-	sort.Slice(sortedIndices, func(i, j int) bool {
-		return sortedIndices[i] < sortedIndices[j]
-	})
+	slices.Sort(sortedIndices)
 
 	if err := committeeCache.AddCommitteeShuffledList(ctx, &cache.Committees{
 		ShuffledIndices: shuffledIndices,

beacon-chain/core/helpers/beacon_committee_test.go

@@ -29,7 +29,7 @@ func TestComputeCommittee_WithoutCache(t *testing.T) {
 	validatorCount := committeeCount * params.BeaconConfig().TargetCommitteeSize
 	validators := make([]*ethpb.Validator, validatorCount)
 
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		k := make([]byte, 48)
 		copy(k, strconv.Itoa(i))
 		validators[i] = &ethpb.Validator{
@@ -122,7 +122,7 @@ func TestCommitteeAssignments_NoProposerForSlot0(t *testing.T) {
 	helpers.ClearCache()
 
 	validators := make([]*ethpb.Validator, 4*params.BeaconConfig().SlotsPerEpoch)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		var activationEpoch primitives.Epoch
 		if i >= len(validators)/2 {
 			activationEpoch = 3
@@ -151,7 +151,7 @@ func TestCommitteeAssignments_CanRetrieve(t *testing.T) {
 	// Initialize test with 256 validators, each slot and each index gets 4 validators.
 	validators := make([]*ethpb.Validator, 4*params.BeaconConfig().SlotsPerEpoch)
 	validatorIndices := make([]primitives.ValidatorIndex, len(validators))
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		// First 2 epochs only half validators are activated.
 		var activationEpoch primitives.Epoch
 		if i >= len(validators)/2 {
@@ -234,7 +234,7 @@ func TestCommitteeAssignments_CannotRetrieveFuture(t *testing.T) {
 
 	// Initialize test with 256 validators, each slot and each index gets 4 validators.
 	validators := make([]*ethpb.Validator, 4*params.BeaconConfig().SlotsPerEpoch)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		// First 2 epochs only half validators are activated.
 		var activationEpoch primitives.Epoch
 		if i >= len(validators)/2 {
@@ -266,7 +266,7 @@ func TestCommitteeAssignments_CannotRetrieveOlderThanSlotsPerHistoricalRoot(t *t
 
 	// Initialize test with 256 validators, each slot and each index gets 4 validators.
 	validators := make([]*ethpb.Validator, 4*params.BeaconConfig().SlotsPerEpoch)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ExitEpoch: params.BeaconConfig().FarFutureEpoch,
 		}
@@ -287,7 +287,7 @@ func TestCommitteeAssignments_EverySlotHasMin1Proposer(t *testing.T) {
 
 	// Initialize test with 256 validators, each slot and each index gets 4 validators.
 	validators := make([]*ethpb.Validator, 4*params.BeaconConfig().SlotsPerEpoch)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ActivationEpoch: 0,
 			ExitEpoch:       params.BeaconConfig().FarFutureEpoch,
@@ -323,7 +323,7 @@ func TestCommitteeAssignments_EverySlotHasMin1Proposer(t *testing.T) {
 func TestVerifyAttestationBitfieldLengths_OK(t *testing.T) {
 	validators := make([]*ethpb.Validator, 2*params.BeaconConfig().SlotsPerEpoch)
 	activeRoots := make([][]byte, params.BeaconConfig().EpochsPerHistoricalVector)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ExitEpoch: params.BeaconConfig().FarFutureEpoch,
 		}
@@ -489,7 +489,7 @@ func TestUpdateCommitteeCache_CanUpdateAcrossEpochs(t *testing.T) {
 
 func BenchmarkComputeCommittee300000_WithPreCache(b *testing.B) {
 	validators := make([]*ethpb.Validator, 300000)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ExitEpoch: params.BeaconConfig().FarFutureEpoch,
 		}
@@ -512,8 +512,7 @@ func BenchmarkComputeCommittee300000_WithPreCache(b *testing.B) {
 		panic(err)
 	}
 
-	b.ResetTimer()
-	for n := 0; n < b.N; n++ {
+	for b.Loop() {
 		_, err := helpers.ComputeCommittee(indices, seed, index, params.BeaconConfig().MaxCommitteesPerSlot)
 		if err != nil {
 			panic(err)
@@ -523,7 +522,7 @@ func BenchmarkComputeCommittee300000_WithPreCache(b *testing.B) {
 
 func BenchmarkComputeCommittee3000000_WithPreCache(b *testing.B) {
 	validators := make([]*ethpb.Validator, 3000000)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ExitEpoch: params.BeaconConfig().FarFutureEpoch,
 		}
@@ -546,8 +545,7 @@ func BenchmarkComputeCommittee3000000_WithPreCache(b *testing.B) {
 		panic(err)
 	}
 
-	b.ResetTimer()
-	for n := 0; n < b.N; n++ {
+	for b.Loop() {
 		_, err := helpers.ComputeCommittee(indices, seed, index, params.BeaconConfig().MaxCommitteesPerSlot)
 		if err != nil {
 			panic(err)
@@ -557,7 +555,7 @@ func BenchmarkComputeCommittee3000000_WithPreCache(b *testing.B) {
 
 func BenchmarkComputeCommittee128000_WithOutPreCache(b *testing.B) {
 	validators := make([]*ethpb.Validator, 128000)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ExitEpoch: params.BeaconConfig().FarFutureEpoch,
 		}
@@ -576,8 +574,8 @@ func BenchmarkComputeCommittee128000_WithOutPreCache(b *testing.B) {
 
 	i := uint64(0)
 	index := uint64(0)
-	b.ResetTimer()
-	for n := 0; n < b.N; n++ {
+
+	for b.Loop() {
 		i++
 		_, err := helpers.ComputeCommittee(indices, seed, index, params.BeaconConfig().MaxCommitteesPerSlot)
 		if err != nil {
@@ -592,7 +590,7 @@ func BenchmarkComputeCommittee128000_WithOutPreCache(b *testing.B) {
 
 func BenchmarkComputeCommittee1000000_WithOutCache(b *testing.B) {
 	validators := make([]*ethpb.Validator, 1000000)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ExitEpoch: params.BeaconConfig().FarFutureEpoch,
 		}
@@ -611,8 +609,8 @@ func BenchmarkComputeCommittee1000000_WithOutCache(b *testing.B) {
 
 	i := uint64(0)
 	index := uint64(0)
-	b.ResetTimer()
-	for n := 0; n < b.N; n++ {
+
+	for b.Loop() {
 		i++
 		_, err := helpers.ComputeCommittee(indices, seed, index, params.BeaconConfig().MaxCommitteesPerSlot)
 		if err != nil {
@@ -627,7 +625,7 @@ func BenchmarkComputeCommittee1000000_WithOutCache(b *testing.B) {
 
 func BenchmarkComputeCommittee4000000_WithOutCache(b *testing.B) {
 	validators := make([]*ethpb.Validator, 4000000)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ExitEpoch: params.BeaconConfig().FarFutureEpoch,
 		}
@@ -646,8 +644,8 @@ func BenchmarkComputeCommittee4000000_WithOutCache(b *testing.B) {
 
 	i := uint64(0)
 	index := uint64(0)
-	b.ResetTimer()
-	for n := 0; n < b.N; n++ {
+
+	for b.Loop() {
 		i++
 		_, err := helpers.ComputeCommittee(indices, seed, index, params.BeaconConfig().MaxCommitteesPerSlot)
 		if err != nil {
@@ -663,7 +661,7 @@ func BenchmarkComputeCommittee4000000_WithOutCache(b *testing.B) {
 func TestBeaconCommitteeFromState_UpdateCacheForPreviousEpoch(t *testing.T) {
 	committeeSize := uint64(16)
 	validators := make([]*ethpb.Validator, params.BeaconConfig().SlotsPerEpoch.Mul(committeeSize))
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ExitEpoch: params.BeaconConfig().FarFutureEpoch,
 		}
@@ -688,7 +686,7 @@ func TestBeaconCommitteeFromState_UpdateCacheForPreviousEpoch(t *testing.T) {
 
 func TestPrecomputeProposerIndices_Ok(t *testing.T) {
 	validators := make([]*ethpb.Validator, params.BeaconConfig().MinGenesisActiveValidatorCount)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ExitEpoch: params.BeaconConfig().FarFutureEpoch,
 		}
@@ -732,7 +730,7 @@ func TestAttestationCommitteesFromState(t *testing.T) {
 	ctx := t.Context()
 
 	validators := make([]*ethpb.Validator, params.BeaconConfig().SlotsPerEpoch.Mul(params.BeaconConfig().TargetCommitteeSize))
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ExitEpoch: params.BeaconConfig().FarFutureEpoch,
 		}
@@ -768,7 +766,7 @@ func TestAttestationCommitteesFromCache(t *testing.T) {
 	ctx := t.Context()
 
 	validators := make([]*ethpb.Validator, params.BeaconConfig().SlotsPerEpoch.Mul(params.BeaconConfig().TargetCommitteeSize))
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ExitEpoch: params.BeaconConfig().FarFutureEpoch,
 		}
@@ -934,7 +932,7 @@ func TestInitializeProposerLookahead_RegressionTest(t *testing.T) {
 	proposerLookahead, err := helpers.InitializeProposerLookahead(ctx, state, epoch)
 	require.NoError(t, err)
 	slotsPerEpoch := int(params.BeaconConfig().SlotsPerEpoch)
-	for epochOffset := primitives.Epoch(0); epochOffset < 2; epochOffset++ {
+	for epochOffset := range primitives.Epoch(2) {
 		targetEpoch := epoch + epochOffset
 
 		activeIndices, err := helpers.ActiveValidatorIndices(ctx, state, targetEpoch)

beacon-chain/core/helpers/randao_test.go

@@ -16,7 +16,7 @@ import (
 
 func TestRandaoMix_OK(t *testing.T) {
 	randaoMixes := make([][]byte, params.BeaconConfig().EpochsPerHistoricalVector)
-	for i := 0; i < len(randaoMixes); i++ {
+	for i := range randaoMixes {
 		intInBytes := make([]byte, 32)
 		binary.LittleEndian.PutUint64(intInBytes, uint64(i))
 		randaoMixes[i] = intInBytes
@@ -52,7 +52,7 @@ func TestRandaoMix_OK(t *testing.T) {
 
 func TestRandaoMix_CopyOK(t *testing.T) {
 	randaoMixes := make([][]byte, params.BeaconConfig().EpochsPerHistoricalVector)
-	for i := 0; i < len(randaoMixes); i++ {
+	for i := range randaoMixes {
 		intInBytes := make([]byte, 32)
 		binary.LittleEndian.PutUint64(intInBytes, uint64(i))
 		randaoMixes[i] = intInBytes
@@ -96,7 +96,7 @@ func TestGenerateSeed_OK(t *testing.T) {
 	helpers.ClearCache()
 
 	randaoMixes := make([][]byte, params.BeaconConfig().EpochsPerHistoricalVector)
-	for i := 0; i < len(randaoMixes); i++ {
+	for i := range randaoMixes {
 		intInBytes := make([]byte, 32)
 		binary.LittleEndian.PutUint64(intInBytes, uint64(i))
 		randaoMixes[i] = intInBytes

beacon-chain/core/helpers/rewards_penalties_test.go

@@ -239,28 +239,28 @@ func TestIsInInactivityLeak(t *testing.T) {
 
 func buildState(slot primitives.Slot, validatorCount uint64) *ethpb.BeaconState {
 	validators := make([]*ethpb.Validator, validatorCount)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ExitEpoch:        params.BeaconConfig().FarFutureEpoch,
 			EffectiveBalance: params.BeaconConfig().MaxEffectiveBalance,
 		}
 	}
 	validatorBalances := make([]uint64, len(validators))
-	for i := 0; i < len(validatorBalances); i++ {
+	for i := range validatorBalances {
 		validatorBalances[i] = params.BeaconConfig().MaxEffectiveBalance
 	}
 	latestActiveIndexRoots := make(
 		[][]byte,
 		params.BeaconConfig().EpochsPerHistoricalVector,
 	)
-	for i := 0; i < len(latestActiveIndexRoots); i++ {
+	for i := range latestActiveIndexRoots {
 		latestActiveIndexRoots[i] = params.BeaconConfig().ZeroHash[:]
 	}
 	latestRandaoMixes := make(
 		[][]byte,
 		params.BeaconConfig().EpochsPerHistoricalVector,
 	)
-	for i := 0; i < len(latestRandaoMixes); i++ {
+	for i := range latestRandaoMixes {
 		latestRandaoMixes[i] = params.BeaconConfig().ZeroHash[:]
 	}
 	return &ethpb.BeaconState{

beacon-chain/core/helpers/shuffle.go

@@ -23,7 +23,7 @@ var maxShuffleListSize uint64 = 1 << 40
 func SplitIndices(l []uint64, n uint64) [][]uint64 {
 	var divided [][]uint64
 	var lSize = uint64(len(l))
-	for i := uint64(0); i < n; i++ {
+	for i := range n {
 		start := slice.SplitOffset(lSize, n, i)
 		end := slice.SplitOffset(lSize, n, i+1)
 		divided = append(divided, l[start:end])
@@ -103,10 +103,7 @@ func ComputeShuffledIndex(index primitives.ValidatorIndex, indexCount uint64, se
 		pivot := hash8Int % indexCount
 		flip := (pivot + indexCount - uint64(index)) % indexCount
 		// Consider every pair only once by picking the highest pair index to retrieve randomness.
-		position := uint64(index)
-		if flip > position {
-			position = flip
-		}
+		position := max(flip, uint64(index))
 		// Add position except its last byte to []buf for randomness,
 		// it will be used later to select a bit from the resulting hash.
 		binary.LittleEndian.PutUint64(posBuffer[:8], position>>8)

beacon-chain/core/helpers/shuffle_test.go

@@ -30,7 +30,7 @@ func TestShuffleList_OK(t *testing.T) {
 	var list1 []primitives.ValidatorIndex
 	seed1 := [32]byte{1, 128, 12}
 	seed2 := [32]byte{2, 128, 12}
-	for i := 0; i < 10; i++ {
+	for i := range 10 {
 		list1 = append(list1, primitives.ValidatorIndex(i))
 	}
 
@@ -55,7 +55,7 @@ func TestSplitIndices_OK(t *testing.T) {
 
 	var l []uint64
 	numValidators := uint64(64000)
-	for i := uint64(0); i < numValidators; i++ {
+	for i := range numValidators {
 		l = append(l, i)
 	}
 	split := SplitIndices(l, uint64(params.BeaconConfig().SlotsPerEpoch))
@@ -104,7 +104,7 @@ func BenchmarkIndexComparison(b *testing.B) {
 	seed := [32]byte{123, 42}
 	for _, listSize := range listSizes {
 		b.Run(fmt.Sprintf("Indexwise_ShuffleList_%d", listSize), func(ib *testing.B) {
-			for i := 0; i < ib.N; i++ {
+			for ib.Loop() {
 				// Simulate a list-shuffle by running shuffle-index listSize times.
 				for j := primitives.ValidatorIndex(0); uint64(j) < listSize; j++ {
 					_, err := ShuffledIndex(j, listSize, seed)
@@ -120,11 +120,11 @@ func BenchmarkShuffleList(b *testing.B) {
 	seed := [32]byte{123, 42}
 	for _, listSize := range listSizes {
 		testIndices := make([]primitives.ValidatorIndex, listSize)
-		for i := uint64(0); i < listSize; i++ {
+		for i := range listSize {
 			testIndices[i] = primitives.ValidatorIndex(i)
 		}
 		b.Run(fmt.Sprintf("ShuffleList_%d", listSize), func(ib *testing.B) {
-			for i := 0; i < ib.N; i++ {
+			for ib.Loop() {
 				_, err := ShuffleList(testIndices, seed)
 				assert.NoError(b, err)
 			}
@@ -161,12 +161,12 @@ func TestSplitIndicesAndOffset_OK(t *testing.T) {
 
 	var l []uint64
 	validators := uint64(64000)
-	for i := uint64(0); i < validators; i++ {
+	for i := range validators {
 		l = append(l, i)
 	}
 	chunks := uint64(6)
 	split := SplitIndices(l, chunks)
-	for i := uint64(0); i < chunks; i++ {
+	for i := range chunks {
 		if !reflect.DeepEqual(split[i], l[slice.SplitOffset(uint64(len(l)), chunks, i):slice.SplitOffset(uint64(len(l)), chunks, i+1)]) {
 			t.Errorf("Want: %v got: %v", l[slice.SplitOffset(uint64(len(l)), chunks, i):slice.SplitOffset(uint64(len(l)), chunks, i+1)], split[i])
 			break

beacon-chain/core/helpers/sync_committee_test.go

@@ -24,7 +24,7 @@ func TestCurrentPeriodPositions(t *testing.T) {
 	syncCommittee := &ethpb.SyncCommittee{
 		Pubkeys: make([][]byte, params.BeaconConfig().SyncCommitteeSize),
 	}
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		k := make([]byte, 48)
 		copy(k, strconv.Itoa(i))
 		validators[i] = &ethpb.Validator{
@@ -56,7 +56,7 @@ func TestIsCurrentEpochSyncCommittee_UsingCache(t *testing.T) {
 	syncCommittee := &ethpb.SyncCommittee{
 		AggregatePubkey: bytesutil.PadTo([]byte{}, params.BeaconConfig().BLSPubkeyLength),
 	}
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		k := make([]byte, 48)
 		copy(k, strconv.Itoa(i))
 		validators[i] = &ethpb.Validator{
@@ -87,7 +87,7 @@ func TestIsCurrentEpochSyncCommittee_UsingCommittee(t *testing.T) {
 	syncCommittee := &ethpb.SyncCommittee{
 		AggregatePubkey: bytesutil.PadTo([]byte{}, params.BeaconConfig().BLSPubkeyLength),
 	}
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		k := make([]byte, 48)
 		copy(k, strconv.Itoa(i))
 		validators[i] = &ethpb.Validator{
@@ -116,7 +116,7 @@ func TestIsCurrentEpochSyncCommittee_DoesNotExist(t *testing.T) {
 	syncCommittee := &ethpb.SyncCommittee{
 		AggregatePubkey: bytesutil.PadTo([]byte{}, params.BeaconConfig().BLSPubkeyLength),
 	}
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		k := make([]byte, 48)
 		copy(k, strconv.Itoa(i))
 		validators[i] = &ethpb.Validator{
@@ -144,7 +144,7 @@ func TestIsNextEpochSyncCommittee_UsingCache(t *testing.T) {
 	syncCommittee := &ethpb.SyncCommittee{
 		AggregatePubkey: bytesutil.PadTo([]byte{}, params.BeaconConfig().BLSPubkeyLength),
 	}
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		k := make([]byte, 48)
 		copy(k, strconv.Itoa(i))
 		validators[i] = &ethpb.Validator{
@@ -175,7 +175,7 @@ func TestIsNextEpochSyncCommittee_UsingCommittee(t *testing.T) {
 	syncCommittee := &ethpb.SyncCommittee{
 		AggregatePubkey: bytesutil.PadTo([]byte{}, params.BeaconConfig().BLSPubkeyLength),
 	}
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		k := make([]byte, 48)
 		copy(k, strconv.Itoa(i))
 		validators[i] = &ethpb.Validator{
@@ -203,7 +203,7 @@ func TestIsNextEpochSyncCommittee_DoesNotExist(t *testing.T) {
 	syncCommittee := &ethpb.SyncCommittee{
 		AggregatePubkey: bytesutil.PadTo([]byte{}, params.BeaconConfig().BLSPubkeyLength),
 	}
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		k := make([]byte, 48)
 		copy(k, strconv.Itoa(i))
 		validators[i] = &ethpb.Validator{
@@ -231,7 +231,7 @@ func TestCurrentEpochSyncSubcommitteeIndices_UsingCache(t *testing.T) {
 	syncCommittee := &ethpb.SyncCommittee{
 		AggregatePubkey: bytesutil.PadTo([]byte{}, params.BeaconConfig().BLSPubkeyLength),
 	}
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		k := make([]byte, 48)
 		copy(k, strconv.Itoa(i))
 		validators[i] = &ethpb.Validator{
@@ -262,7 +262,7 @@ func TestCurrentEpochSyncSubcommitteeIndices_UsingCommittee(t *testing.T) {
 	syncCommittee := &ethpb.SyncCommittee{
 		AggregatePubkey: bytesutil.PadTo([]byte{}, params.BeaconConfig().BLSPubkeyLength),
 	}
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		k := make([]byte, 48)
 		copy(k, strconv.Itoa(i))
 		validators[i] = &ethpb.Validator{
@@ -304,7 +304,7 @@ func TestCurrentEpochSyncSubcommitteeIndices_DoesNotExist(t *testing.T) {
 	syncCommittee := &ethpb.SyncCommittee{
 		AggregatePubkey: bytesutil.PadTo([]byte{}, params.BeaconConfig().BLSPubkeyLength),
 	}
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		k := make([]byte, 48)
 		copy(k, strconv.Itoa(i))
 		validators[i] = &ethpb.Validator{
@@ -332,7 +332,7 @@ func TestNextEpochSyncSubcommitteeIndices_UsingCache(t *testing.T) {
 	syncCommittee := &ethpb.SyncCommittee{
 		AggregatePubkey: bytesutil.PadTo([]byte{}, params.BeaconConfig().BLSPubkeyLength),
 	}
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		k := make([]byte, 48)
 		copy(k, strconv.Itoa(i))
 		validators[i] = &ethpb.Validator{
@@ -363,7 +363,7 @@ func TestNextEpochSyncSubcommitteeIndices_UsingCommittee(t *testing.T) {
 	syncCommittee := &ethpb.SyncCommittee{
 		AggregatePubkey: bytesutil.PadTo([]byte{}, params.BeaconConfig().BLSPubkeyLength),
 	}
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		k := make([]byte, 48)
 		copy(k, strconv.Itoa(i))
 		validators[i] = &ethpb.Validator{
@@ -391,7 +391,7 @@ func TestNextEpochSyncSubcommitteeIndices_DoesNotExist(t *testing.T) {
 	syncCommittee := &ethpb.SyncCommittee{
 		AggregatePubkey: bytesutil.PadTo([]byte{}, params.BeaconConfig().BLSPubkeyLength),
 	}
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		k := make([]byte, 48)
 		copy(k, strconv.Itoa(i))
 		validators[i] = &ethpb.Validator{
@@ -449,7 +449,7 @@ func TestIsCurrentEpochSyncCommittee_SameBlockRoot(t *testing.T) {
 	syncCommittee := &ethpb.SyncCommittee{
 		AggregatePubkey: bytesutil.PadTo([]byte{}, params.BeaconConfig().BLSPubkeyLength),
 	}
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		k := make([]byte, 48)
 		copy(k, strconv.Itoa(i))
 		validators[i] = &ethpb.Validator{

beacon-chain/core/helpers/validators_test.go

@@ -184,7 +184,7 @@ func TestBeaconProposerIndex_OK(t *testing.T) {
 	c.MinGenesisActiveValidatorCount = 16384
 	params.OverrideBeaconConfig(c)
 	validators := make([]*ethpb.Validator, params.BeaconConfig().MinGenesisActiveValidatorCount/8)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ExitEpoch: params.BeaconConfig().FarFutureEpoch,
 		}
@@ -241,7 +241,7 @@ func TestBeaconProposerIndex_BadState(t *testing.T) {
 	c.MinGenesisActiveValidatorCount = 16384
 	params.OverrideBeaconConfig(c)
 	validators := make([]*ethpb.Validator, params.BeaconConfig().MinGenesisActiveValidatorCount/8)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ExitEpoch: params.BeaconConfig().FarFutureEpoch,
 		}
@@ -270,7 +270,7 @@ func TestComputeProposerIndex_Compatibility(t *testing.T) {
 	helpers.ClearCache()
 
 	validators := make([]*ethpb.Validator, params.BeaconConfig().MinGenesisActiveValidatorCount)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ExitEpoch: params.BeaconConfig().FarFutureEpoch,
 		}
@@ -322,7 +322,7 @@ func TestActiveValidatorCount_Genesis(t *testing.T) {
 
 	c := 1000
 	validators := make([]*ethpb.Validator, c)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		validators[i] = &ethpb.Validator{
 			ExitEpoch: params.BeaconConfig().FarFutureEpoch,
 		}
@@ -357,7 +357,7 @@ func TestChurnLimit_OK(t *testing.T) {
 		helpers.ClearCache()
 
 		validators := make([]*ethpb.Validator, test.validatorCount)
-		for i := 0; i < len(validators); i++ {
+		for i := range validators {
 			validators[i] = &ethpb.Validator{
 				ExitEpoch: params.BeaconConfig().FarFutureEpoch,
 			}
@@ -861,7 +861,7 @@ func TestLastActivatedValidatorIndex_OK(t *testing.T) {
 
 	validators := make([]*ethpb.Validator, 4)
 	balances := make([]uint64, len(validators))
-	for i := uint64(0); i < 4; i++ {
+	for i := range uint64(4) {
 		validators[i] = &ethpb.Validator{
 			PublicKey:             make([]byte, params.BeaconConfig().BLSPubkeyLength),
 			WithdrawalCredentials: make([]byte, 32),

beacon-chain/core/helpers/weak_subjectivity_test.go

@@ -270,7 +270,7 @@ func genState(t *testing.T, valCount, avgBalance uint64) state.BeaconState {
 
 	validators := make([]*ethpb.Validator, valCount)
 	balances := make([]uint64, len(validators))
-	for i := uint64(0); i < valCount; i++ {
+	for i := range valCount {
 		validators[i] = &ethpb.Validator{
 			PublicKey:             make([]byte, params.BeaconConfig().BLSPubkeyLength),
 			WithdrawalCredentials: make([]byte, 32),

beacon-chain/core/peerdas/BUILD.bazel

@@ -45,12 +45,13 @@ go_test(
         "p2p_interface_test.go",
         "reconstruction_helpers_test.go",
         "reconstruction_test.go",
+        "semi_supernode_test.go",
         "utils_test.go",
         "validator_test.go",
         "verification_test.go",
     ],
+    embed = [":go_default_library"],
     deps = [
-        ":go_default_library",
         "//beacon-chain/blockchain/kzg:go_default_library",
         "//beacon-chain/state/state-native:go_default_library",
         "//config/fieldparams:go_default_library",

beacon-chain/core/peerdas/das_core.go

@@ -5,6 +5,7 @@ import (
 	"math"
 	"slices"
 
+	fieldparams "github.com/OffchainLabs/prysm/v7/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v7/config/params"
 	"github.com/OffchainLabs/prysm/v7/crypto/hash"
 	"github.com/OffchainLabs/prysm/v7/encoding/bytesutil"
@@ -96,8 +97,7 @@ func ComputeColumnsForCustodyGroup(custodyGroup uint64) ([]uint64, error) {
 		return nil, ErrCustodyGroupTooLarge
 	}
 
-	numberOfColumns := cfg.NumberOfColumns
-
+	numberOfColumns := uint64(fieldparams.NumberOfColumns)
 	columnsPerGroup := numberOfColumns / numberOfCustodyGroups
 
 	columns := make([]uint64, 0, columnsPerGroup)
@@ -112,8 +112,9 @@ func ComputeColumnsForCustodyGroup(custodyGroup uint64) ([]uint64, error) {
 // ComputeCustodyGroupForColumn computes the custody group for a given column.
 // It is the reciprocal function of ComputeColumnsForCustodyGroup.
 func ComputeCustodyGroupForColumn(columnIndex uint64) (uint64, error) {
+	const numberOfColumns = fieldparams.NumberOfColumns
+
 	cfg := params.BeaconConfig()
-	numberOfColumns := cfg.NumberOfColumns
 	numberOfCustodyGroups := cfg.NumberOfCustodyGroups
 
 	if columnIndex >= numberOfColumns {

beacon-chain/core/peerdas/das_core_test.go

@@ -30,7 +30,6 @@ func TestComputeColumnsForCustodyGroup(t *testing.T) {
 func TestComputeCustodyGroupForColumn(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
 	config := params.BeaconConfig()
-	config.NumberOfColumns = 128
 	config.NumberOfCustodyGroups = 64
 	params.OverrideBeaconConfig(config)
 

beacon-chain/core/peerdas/info.go

@@ -2,6 +2,7 @@ package peerdas
 
 import (
 	"encoding/binary"
+	"maps"
 	"sync"
 
 	"github.com/ethereum/go-ethereum/p2p/enode"
@@ -107,3 +108,102 @@ func computeInfoCacheKey(nodeID enode.ID, custodyGroupCount uint64) [nodeInfoCac
 
 	return key
 }
+
+// ColumnIndices represents as a set of ColumnIndices. This could be the set of indices that a node is required to custody,
+// the set that a peer custodies, missing indices for a given block, indices that are present on disk, etc.
+type ColumnIndices map[uint64]struct{}
+
+// Has returns true if the index is present in the ColumnIndices.
+func (ci ColumnIndices) Has(index uint64) bool {
+	_, ok := ci[index]
+	return ok
+}
+
+// Count returns the number of indices present in the ColumnIndices.
+func (ci ColumnIndices) Count() int {
+	return len(ci)
+}
+
+// Set sets the index in the ColumnIndices.
+func (ci ColumnIndices) Set(index uint64) {
+	ci[index] = struct{}{}
+}
+
+// Unset removes the index from the ColumnIndices.
+func (ci ColumnIndices) Unset(index uint64) {
+	delete(ci, index)
+}
+
+// Copy creates a copy of the ColumnIndices.
+func (ci ColumnIndices) Copy() ColumnIndices {
+	newCi := make(ColumnIndices, len(ci))
+	maps.Copy(newCi, ci)
+	return newCi
+}
+
+// Intersection returns a new ColumnIndices that contains only the indices that are present in both ColumnIndices.
+func (ci ColumnIndices) Intersection(other ColumnIndices) ColumnIndices {
+	result := make(ColumnIndices)
+	for index := range ci {
+		if other.Has(index) {
+			result.Set(index)
+		}
+	}
+	return result
+}
+
+// Merge mutates the receiver so that any index that is set in either of
+// the two ColumnIndices is set in the receiver after the function finishes.
+// It does not mutate the other ColumnIndices given as a function argument.
+func (ci ColumnIndices) Merge(other ColumnIndices) {
+	for index := range other {
+		ci.Set(index)
+	}
+}
+
+// ToMap converts a ColumnIndices into a map[uint64]struct{}.
+// In the future ColumnIndices may be changed to a bit map, so using
+// ToMap will ensure forwards-compatibility.
+func (ci ColumnIndices) ToMap() map[uint64]struct{} {
+	return ci.Copy()
+}
+
+// ToSlice converts a ColumnIndices into a slice of uint64 indices.
+func (ci ColumnIndices) ToSlice() []uint64 {
+	indices := make([]uint64, 0, len(ci))
+	for index := range ci {
+		indices = append(indices, index)
+	}
+	return indices
+}
+
+// NewColumnIndicesFromSlice creates a ColumnIndices from a slice of uint64.
+func NewColumnIndicesFromSlice(indices []uint64) ColumnIndices {
+	ci := make(ColumnIndices, len(indices))
+	for _, index := range indices {
+		ci[index] = struct{}{}
+	}
+	return ci
+}
+
+// NewColumnIndicesFromMap creates a ColumnIndices from a map[uint64]bool. This kind of map
+// is used in several places in peerdas code. Converting from this map type to ColumnIndices
+// will allow us to move ColumnIndices underlying type to a bitmap in the future and avoid
+// lots of loops for things like intersections/unions or copies.
+func NewColumnIndicesFromMap(indices map[uint64]bool) ColumnIndices {
+	ci := make(ColumnIndices, len(indices))
+	for index, set := range indices {
+		if !set {
+			continue
+		}
+		ci[index] = struct{}{}
+	}
+	return ci
+}
+
+// NewColumnIndices creates an empty ColumnIndices.
+// In the future ColumnIndices may change from a reference type to a value type,
+// so using this constructor will ensure forwards-compatibility.
+func NewColumnIndices() ColumnIndices {
+	return make(ColumnIndices)
+}

beacon-chain/core/peerdas/info_test.go

@@ -25,3 +25,10 @@ func TestInfo(t *testing.T) {
 		require.DeepEqual(t, expectedDataColumnsSubnets, actual.DataColumnsSubnets)
 	}
 }
+
+func TestNewColumnIndicesFromMap(t *testing.T) {
+	t.Run("nil map", func(t *testing.T) {
+		ci := peerdas.NewColumnIndicesFromMap(nil)
+		require.Equal(t, 0, ci.Count())
+	})
+}

beacon-chain/core/peerdas/p2p_interface.go

@@ -33,8 +33,7 @@ func (Cgc) ENRKey() string { return params.BeaconNetworkConfig().CustodyGroupCou
 // https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/p2p-interface.md#verify_data_column_sidecar
 func VerifyDataColumnSidecar(sidecar blocks.RODataColumn) error {
 	// The sidecar index must be within the valid range.
-	numberOfColumns := params.BeaconConfig().NumberOfColumns
-	if sidecar.Index >= numberOfColumns {
+	if sidecar.Index >= fieldparams.NumberOfColumns {
 		return ErrIndexTooLarge
 	}
 

beacon-chain/core/peerdas/p2p_interface_test.go

@@ -100,7 +100,7 @@ func Test_VerifyKZGInclusionProofColumn(t *testing.T) {
 	// Generate random KZG commitments `blobCount` blobs.
 	kzgCommitments := make([][]byte, blobCount)
 
-	for i := 0; i < blobCount; i++ {
+	for i := range blobCount {
 		kzgCommitments[i] = make([]byte, 48)
 		_, err := rand.Read(kzgCommitments[i])
 		require.NoError(t, err)
@@ -281,8 +281,11 @@ func BenchmarkVerifyDataColumnSidecarKZGProofs_SameCommitments_NoBatch(b *testin
 }
 
 func BenchmarkVerifyDataColumnSidecarKZGProofs_DiffCommitments_Batch(b *testing.B) {
-	const blobCount = 12
-	numberOfColumns := int64(params.BeaconConfig().NumberOfColumns)
+	const (
+		blobCount       = 12
+		numberOfColumns = fieldparams.NumberOfColumns
+	)
+
 	err := kzg.Start()
 	require.NoError(b, err)
 

beacon-chain/core/peerdas/reconstruction.go

@@ -26,7 +26,40 @@ var (
 func MinimumColumnCountToReconstruct() uint64 {
 	// If the number of columns is odd, then we need total / 2 + 1 columns to reconstruct.
 	// If the number of columns is even, then we need total / 2 columns to reconstruct.
-	return (params.BeaconConfig().NumberOfColumns + 1) / 2
+	return (fieldparams.NumberOfColumns + 1) / 2
+}
+
+// MinimumCustodyGroupCountToReconstruct returns the minimum number of custody groups needed to
+// custody enough data columns for reconstruction. This accounts for the relationship between
+// custody groups and columns, making it future-proof if these values change.
+// Returns an error if the configuration values are invalid (zero or would cause division by zero).
+func MinimumCustodyGroupCountToReconstruct() (uint64, error) {
+	const numberOfColumns = fieldparams.NumberOfColumns
+	cfg := params.BeaconConfig()
+
+	// Validate configuration values
+	if numberOfColumns == 0 {
+		return 0, errors.New("NumberOfColumns cannot be zero")
+	}
+	if cfg.NumberOfCustodyGroups == 0 {
+		return 0, errors.New("NumberOfCustodyGroups cannot be zero")
+	}
+
+	minimumColumnCount := MinimumColumnCountToReconstruct()
+
+	// Calculate how many columns each custody group represents
+	columnsPerGroup := numberOfColumns / cfg.NumberOfCustodyGroups
+
+	// If there are more groups than columns (columnsPerGroup = 0), this is an invalid configuration
+	// for reconstruction purposes as we cannot determine a meaningful custody group count
+	if columnsPerGroup == 0 {
+		return 0, errors.Errorf("invalid configuration: NumberOfCustodyGroups (%d) exceeds NumberOfColumns (%d)",
+			cfg.NumberOfCustodyGroups, numberOfColumns)
+	}
+
+	// Use ceiling division to ensure we have enough groups to cover the minimum columns
+	// ceiling(a/b) = (a + b - 1) / b
+	return (minimumColumnCount + columnsPerGroup - 1) / columnsPerGroup, nil
 }
 
 // recoverCellsForBlobs reconstructs cells for specified blobs from the given data column sidecars.
@@ -253,7 +286,8 @@ func ReconstructBlobSidecars(block blocks.ROBlock, verifiedDataColumnSidecars []
 
 // ComputeCellsAndProofsFromFlat computes the cells and proofs from blobs and cell flat proofs.
 func ComputeCellsAndProofsFromFlat(blobs [][]byte, cellProofs [][]byte) ([][]kzg.Cell, [][]kzg.Proof, error) {
-	numberOfColumns := params.BeaconConfig().NumberOfColumns
+	const numberOfColumns = fieldparams.NumberOfColumns
+
 	blobCount := uint64(len(blobs))
 	cellProofsCount := uint64(len(cellProofs))
 
@@ -295,8 +329,6 @@ func ComputeCellsAndProofsFromFlat(blobs [][]byte, cellProofs [][]byte) ([][]kzg
 
 // ComputeCellsAndProofsFromStructured computes the cells and proofs from blobs and cell proofs.
 func ComputeCellsAndProofsFromStructured(blobsAndProofs []*pb.BlobAndProofV2) ([][]kzg.Cell, [][]kzg.Proof, error) {
-	numberOfColumns := params.BeaconConfig().NumberOfColumns
-
 	cellsPerBlob := make([][]kzg.Cell, 0, len(blobsAndProofs))
 	proofsPerBlob := make([][]kzg.Proof, 0, len(blobsAndProofs))
 	for _, blobAndProof := range blobsAndProofs {
@@ -315,7 +347,7 @@ func ComputeCellsAndProofsFromStructured(blobsAndProofs []*pb.BlobAndProofV2) ([
 			return nil, nil, errors.Wrap(err, "compute cells")
 		}
 
-		kzgProofs := make([]kzg.Proof, 0, numberOfColumns)
+		kzgProofs := make([]kzg.Proof, 0, fieldparams.NumberOfColumns)
 		for _, kzgProofBytes := range blobAndProof.KzgProofs {
 			if len(kzgProofBytes) != kzg.BytesPerProof {
 				return nil, nil, errors.New("wrong KZG proof size - should never happen")

beacon-chain/core/peerdas/reconstruction_helpers_test.go

@@ -16,11 +16,11 @@ import (
 
 // testBlobSetup holds common test data for blob reconstruction tests.
 type testBlobSetup struct {
-	blobCount                     int
-	blobs                         []kzg.Blob
-	roBlock                       blocks.ROBlock
-	roDataColumnSidecars          []blocks.RODataColumn
-	verifiedRoDataColumnSidecars  []blocks.VerifiedRODataColumn
+	blobCount                    int
+	blobs                        []kzg.Blob
+	roBlock                      blocks.ROBlock
+	roDataColumnSidecars         []blocks.RODataColumn
+	verifiedRoDataColumnSidecars []blocks.VerifiedRODataColumn
 }
 
 // setupTestBlobs creates a complete test setup with blobs, cells, proofs, and data column sidecars.

beacon-chain/core/peerdas/reconstruction_test.go

@@ -17,41 +17,9 @@ import (
 )
 
 func TestMinimumColumnsCountToReconstruct(t *testing.T) {
-	testCases := []struct {
-		name            string
-		numberOfColumns uint64
-		expected        uint64
-	}{
-		{
-			name:            "numberOfColumns=128",
-			numberOfColumns: 128,
-			expected:        64,
-		},
-		{
-			name:            "numberOfColumns=129",
-			numberOfColumns: 129,
-			expected:        65,
-		},
-		{
-			name:            "numberOfColumns=130",
-			numberOfColumns: 130,
-			expected:        65,
-		},
-	}
-
-	for _, tc := range testCases {
-		t.Run(tc.name, func(t *testing.T) {
-			// Set the total number of columns.
-			params.SetupTestConfigCleanup(t)
-			cfg := params.BeaconConfig().Copy()
-			cfg.NumberOfColumns = tc.numberOfColumns
-			params.OverrideBeaconConfig(cfg)
-
-			// Compute the minimum number of columns needed to reconstruct.
-			actual := peerdas.MinimumColumnCountToReconstruct()
-			require.Equal(t, tc.expected, actual)
-		})
-	}
+	const expected = uint64(64)
+	actual := peerdas.MinimumColumnCountToReconstruct()
+	require.Equal(t, expected, actual)
 }
 
 func TestReconstructDataColumnSidecars(t *testing.T) {
@@ -200,7 +168,6 @@ func TestReconstructBlobSidecars(t *testing.T) {
 
 	t.Run("nominal", func(t *testing.T) {
 		const blobCount = 3
-		numberOfColumns := params.BeaconConfig().NumberOfColumns
 
 		roBlock, roBlobSidecars := util.GenerateTestElectraBlockWithSidecar(t, [fieldparams.RootLength]byte{}, 42, blobCount)
 
@@ -236,7 +203,7 @@ func TestReconstructBlobSidecars(t *testing.T) {
 		require.NoError(t, err)
 
 		// Flatten proofs.
-		cellProofs := make([][]byte, 0, blobCount*numberOfColumns)
+		cellProofs := make([][]byte, 0, blobCount*fieldparams.NumberOfColumns)
 		for _, proofs := range inputProofsPerBlob {
 			for _, proof := range proofs {
 				cellProofs = append(cellProofs, proof[:])
@@ -428,13 +395,12 @@ func TestReconstructBlobs(t *testing.T) {
 }
 
 func TestComputeCellsAndProofsFromFlat(t *testing.T) {
+	const numberOfColumns = fieldparams.NumberOfColumns
 	// Start the trusted setup.
 	err := kzg.Start()
 	require.NoError(t, err)
 
 	t.Run("mismatched blob and proof counts", func(t *testing.T) {
-		numberOfColumns := params.BeaconConfig().NumberOfColumns
-
 		// Create one blob but proofs for two blobs
 		blobs := [][]byte{{}}
 
@@ -447,7 +413,6 @@ func TestComputeCellsAndProofsFromFlat(t *testing.T) {
 
 	t.Run("nominal", func(t *testing.T) {
 		const blobCount = 2
-		numberOfColumns := params.BeaconConfig().NumberOfColumns
 
 		// Generate test blobs
 		_, roBlobSidecars := util.GenerateTestElectraBlockWithSidecar(t, [fieldparams.RootLength]byte{}, 42, blobCount)

beacon-chain/core/peerdas/semi_supernode_test.go

@@ -0,0 +1,137 @@
+package peerdas
+
+import (
+	"testing"
+
+	fieldparams "github.com/OffchainLabs/prysm/v7/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v7/config/params"
+	"github.com/OffchainLabs/prysm/v7/testing/require"
+	"github.com/ethereum/go-ethereum/p2p/enode"
+)
+
+func TestSemiSupernodeCustody(t *testing.T) {
+	const numberOfColumns = fieldparams.NumberOfColumns
+
+	params.SetupTestConfigCleanup(t)
+	cfg := params.BeaconConfig()
+	cfg.NumberOfCustodyGroups = 128
+	params.OverrideBeaconConfig(cfg)
+
+	// Create a test node ID
+	nodeID := enode.ID([32]byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32})
+
+	t.Run("semi-supernode custodies exactly 64 columns", func(t *testing.T) {
+		// Semi-supernode uses 64 custody groups (half of 128)
+		const semiSupernodeCustodyGroupCount = 64
+
+		// Get custody groups for semi-supernode
+		custodyGroups, err := CustodyGroups(nodeID, semiSupernodeCustodyGroupCount)
+		require.NoError(t, err)
+		require.Equal(t, semiSupernodeCustodyGroupCount, len(custodyGroups))
+
+		// Verify we get exactly 64 custody columns
+		custodyColumns, err := CustodyColumns(custodyGroups)
+		require.NoError(t, err)
+		require.Equal(t, semiSupernodeCustodyGroupCount, len(custodyColumns))
+
+		// Verify the columns are valid (within 0-127 range)
+		for columnIndex := range custodyColumns {
+			if columnIndex >= numberOfColumns {
+				t.Fatalf("Invalid column index %d, should be less than %d", columnIndex, numberOfColumns)
+			}
+		}
+	})
+
+	t.Run("64 columns is exactly the minimum for reconstruction", func(t *testing.T) {
+		minimumCount := MinimumColumnCountToReconstruct()
+		require.Equal(t, uint64(64), minimumCount)
+	})
+
+	t.Run("semi-supernode vs supernode custody", func(t *testing.T) {
+		// Semi-supernode (64 custody groups)
+		semiSupernodeGroups, err := CustodyGroups(nodeID, 64)
+		require.NoError(t, err)
+		semiSupernodeColumns, err := CustodyColumns(semiSupernodeGroups)
+		require.NoError(t, err)
+
+		// Supernode (128 custody groups = all groups)
+		supernodeGroups, err := CustodyGroups(nodeID, 128)
+		require.NoError(t, err)
+		supernodeColumns, err := CustodyColumns(supernodeGroups)
+		require.NoError(t, err)
+
+		// Verify semi-supernode has exactly half the columns of supernode
+		require.Equal(t, 64, len(semiSupernodeColumns))
+		require.Equal(t, 128, len(supernodeColumns))
+		require.Equal(t, len(supernodeColumns)/2, len(semiSupernodeColumns))
+
+		// Verify all semi-supernode columns are a subset of supernode columns
+		for columnIndex := range semiSupernodeColumns {
+			if !supernodeColumns[columnIndex] {
+				t.Fatalf("Semi-supernode column %d not found in supernode columns", columnIndex)
+			}
+		}
+	})
+}
+
+func TestMinimumCustodyGroupCountToReconstruct(t *testing.T) {
+	tests := []struct {
+		name           string
+		numberOfGroups uint64
+		expectedResult uint64
+	}{
+		{
+			name:           "Standard 1:1 ratio (128 columns, 128 groups)",
+			numberOfGroups: 128,
+			expectedResult: 64, // Need half of 128 groups
+		},
+		{
+			name:           "2 columns per group (128 columns, 64 groups)",
+			numberOfGroups: 64,
+			expectedResult: 32, // Need 64 columns, which is 32 groups (64/2)
+		},
+		{
+			name:           "4 columns per group (128 columns, 32 groups)",
+			numberOfGroups: 32,
+			expectedResult: 16, // Need 64 columns, which is 16 groups (64/4)
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			params.SetupTestConfigCleanup(t)
+			cfg := params.BeaconConfig()
+			cfg.NumberOfCustodyGroups = tt.numberOfGroups
+			params.OverrideBeaconConfig(cfg)
+
+			result, err := MinimumCustodyGroupCountToReconstruct()
+			require.NoError(t, err)
+			require.Equal(t, tt.expectedResult, result)
+		})
+	}
+}
+
+func TestMinimumCustodyGroupCountToReconstruct_ErrorCases(t *testing.T) {
+	t.Run("Returns error when NumberOfCustodyGroups is zero", func(t *testing.T) {
+		params.SetupTestConfigCleanup(t)
+		cfg := params.BeaconConfig()
+		cfg.NumberOfCustodyGroups = 0
+		params.OverrideBeaconConfig(cfg)
+
+		_, err := MinimumCustodyGroupCountToReconstruct()
+		require.NotNil(t, err)
+		require.Equal(t, true, err.Error() == "NumberOfCustodyGroups cannot be zero")
+	})
+
+	t.Run("Returns error when NumberOfCustodyGroups exceeds NumberOfColumns", func(t *testing.T) {
+		params.SetupTestConfigCleanup(t)
+		cfg := params.BeaconConfig()
+		cfg.NumberOfCustodyGroups = 256
+		params.OverrideBeaconConfig(cfg)
+
+		_, err := MinimumCustodyGroupCountToReconstruct()
+		require.NotNil(t, err)
+		// Just check that we got an error about the configuration
+		require.Equal(t, true, len(err.Error()) > 0)
+	})
+}

beacon-chain/core/peerdas/validator.go

@@ -102,11 +102,13 @@ func ValidatorsCustodyRequirement(state beaconState.ReadOnlyBeaconState, validat
 // https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/validator.md#get_data_column_sidecars_from_block and
 // https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/validator.md#get_data_column_sidecars_from_column_sidecar
 func DataColumnSidecars(cellsPerBlob [][]kzg.Cell, proofsPerBlob [][]kzg.Proof, src ConstructionPopulator) ([]blocks.RODataColumn, error) {
+	const numberOfColumns = uint64(fieldparams.NumberOfColumns)
+
 	if len(cellsPerBlob) == 0 {
 		return nil, nil
 	}
 	start := time.Now()
-	cells, proofs, err := rotateRowsToCols(cellsPerBlob, proofsPerBlob, params.BeaconConfig().NumberOfColumns)
+	cells, proofs, err := rotateRowsToCols(cellsPerBlob, proofsPerBlob, numberOfColumns)
 	if err != nil {
 		return nil, errors.Wrap(err, "rotate cells and proofs")
 	}
@@ -115,9 +117,8 @@ func DataColumnSidecars(cellsPerBlob [][]kzg.Cell, proofsPerBlob [][]kzg.Proof,
 		return nil, errors.Wrap(err, "extract block info")
 	}
 
-	maxIdx := params.BeaconConfig().NumberOfColumns
-	roSidecars := make([]blocks.RODataColumn, 0, maxIdx)
-	for idx := range maxIdx {
+	roSidecars := make([]blocks.RODataColumn, 0, numberOfColumns)
+	for idx := range numberOfColumns {
 		sidecar := &ethpb.DataColumnSidecar{
 			Index:                        idx,
 			Column:                       cells[idx],
@@ -216,7 +217,7 @@ func rotateRowsToCols(cellsPerBlob [][]kzg.Cell, proofsPerBlob [][]kzg.Proof, nu
 		if len(cells) != len(proofs) {
 			return nil, nil, errors.Wrap(ErrNotEnoughDataColumnSidecars, "not enough proofs")
 		}
-		for j := uint64(0); j < numCols; j++ {
+		for j := range numCols {
 			if i == 0 {
 				cellCols[j] = make([][]byte, len(cellsPerBlob))
 				proofCols[j] = make([][]byte, len(cellsPerBlob))

beacon-chain/core/peerdas/validator_test.go

@@ -6,7 +6,7 @@ import (
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/blockchain/kzg"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/core/peerdas"
 	state_native "github.com/OffchainLabs/prysm/v7/beacon-chain/state/state-native"
-	"github.com/OffchainLabs/prysm/v7/config/params"
+	fieldparams "github.com/OffchainLabs/prysm/v7/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v7/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v7/consensus-types/primitives"
 	ethpb "github.com/OffchainLabs/prysm/v7/proto/prysm/v1alpha1"
@@ -59,6 +59,8 @@ func TestValidatorsCustodyRequirement(t *testing.T) {
 }
 
 func TestDataColumnSidecars(t *testing.T) {
+	const numberOfColumns = fieldparams.NumberOfColumns
+
 	t.Run("sizes mismatch", func(t *testing.T) {
 		// Create a protobuf signed beacon block.
 		signedBeaconBlockPb := util.NewBeaconBlockDeneb()
@@ -69,10 +71,10 @@ func TestDataColumnSidecars(t *testing.T) {
 
 		// Create cells and proofs.
 		cellsPerBlob := [][]kzg.Cell{
-			make([]kzg.Cell, params.BeaconConfig().NumberOfColumns),
+			make([]kzg.Cell, numberOfColumns),
 		}
 		proofsPerBlob := [][]kzg.Proof{
-			make([]kzg.Proof, params.BeaconConfig().NumberOfColumns),
+			make([]kzg.Proof, numberOfColumns),
 		}
 
 		rob, err := blocks.NewROBlock(signedBeaconBlock)
@@ -117,7 +119,6 @@ func TestDataColumnSidecars(t *testing.T) {
 		require.NoError(t, err)
 
 		// Create cells and proofs with sufficient cells but insufficient proofs.
-		numberOfColumns := params.BeaconConfig().NumberOfColumns
 		cellsPerBlob := [][]kzg.Cell{
 			make([]kzg.Cell, numberOfColumns),
 		}
@@ -149,7 +150,6 @@ func TestDataColumnSidecars(t *testing.T) {
 		require.NoError(t, err)
 
 		// Create cells and proofs with correct dimensions.
-		numberOfColumns := params.BeaconConfig().NumberOfColumns
 		cellsPerBlob := [][]kzg.Cell{
 			make([]kzg.Cell, numberOfColumns),
 			make([]kzg.Cell, numberOfColumns),
@@ -197,6 +197,7 @@ func TestDataColumnSidecars(t *testing.T) {
 }
 
 func TestReconstructionSource(t *testing.T) {
+	const numberOfColumns = fieldparams.NumberOfColumns
 	// Create a Fulu block with blob commitments.
 	signedBeaconBlockPb := util.NewBeaconBlockFulu()
 	commitment1 := make([]byte, 48)
@@ -212,7 +213,6 @@ func TestReconstructionSource(t *testing.T) {
 	require.NoError(t, err)
 
 	// Create cells and proofs with correct dimensions.
-	numberOfColumns := params.BeaconConfig().NumberOfColumns
 	cellsPerBlob := [][]kzg.Cell{
 		make([]kzg.Cell, numberOfColumns),
 		make([]kzg.Cell, numberOfColumns),

beacon-chain/core/signing/signing_root_test.go

@@ -119,7 +119,7 @@ func TestFuzzverifySigningRoot_10000(_ *testing.T) {
 	var p []byte
 	var s []byte
 	var d []byte
-	for i := 0; i < 10000; i++ {
+	for range 10000 {
 		fuzzer.Fuzz(st)
 		fuzzer.Fuzz(&pubkey)
 		fuzzer.Fuzz(&sig)

beacon-chain/core/transition/benchmarks_test.go

@@ -28,8 +28,7 @@ func BenchmarkExecuteStateTransition_FullBlock(b *testing.B) {
 	block, err := benchmark.PreGenFullBlock()
 	require.NoError(b, err)
 
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+	for i := 0; b.Loop(); i++ {
 		wsb, err := blocks.NewSignedBeaconBlock(block)
 		require.NoError(b, err)
 		_, err = coreState.ExecuteStateTransition(b.Context(), cleanStates[i], wsb)
@@ -60,8 +59,7 @@ func BenchmarkExecuteStateTransition_WithCache(b *testing.B) {
 	_, err = coreState.ExecuteStateTransition(b.Context(), beaconState, wsb)
 	require.NoError(b, err, "Failed to process block, benchmarks will fail")
 
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+	for i := 0; b.Loop(); i++ {
 		wsb, err := blocks.NewSignedBeaconBlock(block)
 		require.NoError(b, err)
 		_, err = coreState.ExecuteStateTransition(b.Context(), cleanStates[i], wsb)
@@ -83,8 +81,7 @@ func BenchmarkProcessEpoch_2FullEpochs(b *testing.B) {
 	require.NoError(b, helpers.UpdateCommitteeCache(b.Context(), beaconState, time.CurrentEpoch(beaconState)))
 	require.NoError(b, beaconState.SetSlot(currentSlot))
 
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		// ProcessEpochPrecompute is the optimized version of process epoch. It's enabled by default
 		// at run time.
 		_, err := coreState.ProcessEpochPrecompute(b.Context(), beaconState.Copy())
@@ -96,8 +93,7 @@ func BenchmarkHashTreeRoot_FullState(b *testing.B) {
 	beaconState, err := benchmark.PreGenstateFullEpochs()
 	require.NoError(b, err)
 
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		_, err := beaconState.HashTreeRoot(b.Context())
 		require.NoError(b, err)
 	}
@@ -113,8 +109,7 @@ func BenchmarkHashTreeRootState_FullState(b *testing.B) {
 	_, err = beaconState.HashTreeRoot(ctx)
 	require.NoError(b, err)
 
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		_, err := beaconState.HashTreeRoot(ctx)
 		require.NoError(b, err)
 	}
@@ -128,7 +123,7 @@ func BenchmarkMarshalState_FullState(b *testing.B) {
 	b.Run("Proto_Marshal", func(b *testing.B) {
 		b.ResetTimer()
 		b.ReportAllocs()
-		for i := 0; i < b.N; i++ {
+		for b.Loop() {
 			_, err := proto.Marshal(natState)
 			require.NoError(b, err)
 		}
@@ -137,7 +132,7 @@ func BenchmarkMarshalState_FullState(b *testing.B) {
 	b.Run("Fast_SSZ_Marshal", func(b *testing.B) {
 		b.ResetTimer()
 		b.ReportAllocs()
-		for i := 0; i < b.N; i++ {
+		for b.Loop() {
 			_, err := natState.MarshalSSZ()
 			require.NoError(b, err)
 		}
@@ -157,7 +152,7 @@ func BenchmarkUnmarshalState_FullState(b *testing.B) {
 	b.Run("Proto_Unmarshal", func(b *testing.B) {
 		b.ResetTimer()
 		b.ReportAllocs()
-		for i := 0; i < b.N; i++ {
+		for b.Loop() {
 			require.NoError(b, proto.Unmarshal(protoObject, &ethpb.BeaconState{}))
 		}
 	})
@@ -165,7 +160,7 @@ func BenchmarkUnmarshalState_FullState(b *testing.B) {
 	b.Run("Fast_SSZ_Unmarshal", func(b *testing.B) {
 		b.ResetTimer()
 		b.ReportAllocs()
-		for i := 0; i < b.N; i++ {
+		for b.Loop() {
 			sszState := &ethpb.BeaconState{}
 			require.NoError(b, sszState.UnmarshalSSZ(sszObject))
 		}
@@ -174,7 +169,7 @@ func BenchmarkUnmarshalState_FullState(b *testing.B) {
 
 func clonedStates(beaconState state.BeaconState) []state.BeaconState {
 	clonedStates := make([]state.BeaconState, runAmount)
-	for i := 0; i < runAmount; i++ {
+	for i := range runAmount {
 		clonedStates[i] = beaconState.Copy()
 	}
 	return clonedStates

beacon-chain/core/transition/skip_slot_cache_test.go

@@ -108,7 +108,7 @@ func TestSkipSlotCache_ConcurrentMixup(t *testing.T) {
 
 	// prepare copies for both states
 	var setups []state.BeaconState
-	for i := uint64(0); i < 300; i++ {
+	for i := range uint64(300) {
 		var st state.BeaconState
 		if i%2 == 0 {
 			st = s1

beacon-chain/core/transition/state-bellatrix.go

@@ -95,7 +95,7 @@ func OptimizedGenesisBeaconStateBellatrix(genesisTime uint64, preState state.Bea
 	}
 
 	randaoMixes := make([][]byte, params.BeaconConfig().EpochsPerHistoricalVector)
-	for i := 0; i < len(randaoMixes); i++ {
+	for i := range randaoMixes {
 		h := make([]byte, 32)
 		copy(h, eth1Data.BlockHash)
 		randaoMixes[i] = h
@@ -104,17 +104,17 @@ func OptimizedGenesisBeaconStateBellatrix(genesisTime uint64, preState state.Bea
 	zeroHash := params.BeaconConfig().ZeroHash[:]
 
 	activeIndexRoots := make([][]byte, params.BeaconConfig().EpochsPerHistoricalVector)
-	for i := 0; i < len(activeIndexRoots); i++ {
+	for i := range activeIndexRoots {
 		activeIndexRoots[i] = zeroHash
 	}
 
 	blockRoots := make([][]byte, params.BeaconConfig().SlotsPerHistoricalRoot)
-	for i := 0; i < len(blockRoots); i++ {
+	for i := range blockRoots {
 		blockRoots[i] = zeroHash
 	}
 
 	stateRoots := make([][]byte, params.BeaconConfig().SlotsPerHistoricalRoot)
-	for i := 0; i < len(stateRoots); i++ {
+	for i := range stateRoots {
 		stateRoots[i] = zeroHash
 	}
 
@@ -131,7 +131,7 @@ func OptimizedGenesisBeaconStateBellatrix(genesisTime uint64, preState state.Bea
 	}
 	scoresMissing := len(preState.Validators()) - len(scores)
 	if scoresMissing > 0 {
-		for i := 0; i < scoresMissing; i++ {
+		for range scoresMissing {
 			scores = append(scores, 0)
 		}
 	}

beacon-chain/core/transition/state.go

@@ -122,7 +122,7 @@ func OptimizedGenesisBeaconState(genesisTime uint64, preState state.BeaconState,
 	}
 
 	randaoMixes := make([][]byte, params.BeaconConfig().EpochsPerHistoricalVector)
-	for i := 0; i < len(randaoMixes); i++ {
+	for i := range randaoMixes {
 		h := make([]byte, 32)
 		copy(h, eth1Data.BlockHash)
 		randaoMixes[i] = h
@@ -131,17 +131,17 @@ func OptimizedGenesisBeaconState(genesisTime uint64, preState state.BeaconState,
 	zeroHash := params.BeaconConfig().ZeroHash[:]
 
 	activeIndexRoots := make([][]byte, params.BeaconConfig().EpochsPerHistoricalVector)
-	for i := 0; i < len(activeIndexRoots); i++ {
+	for i := range activeIndexRoots {
 		activeIndexRoots[i] = zeroHash
 	}
 
 	blockRoots := make([][]byte, params.BeaconConfig().SlotsPerHistoricalRoot)
-	for i := 0; i < len(blockRoots); i++ {
+	for i := range blockRoots {
 		blockRoots[i] = zeroHash
 	}
 
 	stateRoots := make([][]byte, params.BeaconConfig().SlotsPerHistoricalRoot)
-	for i := 0; i < len(stateRoots); i++ {
+	for i := range stateRoots {
 		stateRoots[i] = zeroHash
 	}
 

beacon-chain/core/transition/state_fuzz_test.go

@@ -17,7 +17,7 @@ func TestGenesisBeaconState_1000(t *testing.T) {
 	deposits := make([]*ethpb.Deposit, 300000)
 	var genesisTime uint64
 	eth1Data := &ethpb.Eth1Data{}
-	for i := 0; i < 1000; i++ {
+	for range 1000 {
 		fuzzer.Fuzz(&deposits)
 		fuzzer.Fuzz(&genesisTime)
 		fuzzer.Fuzz(eth1Data)
@@ -40,7 +40,7 @@ func TestOptimizedGenesisBeaconState_1000(t *testing.T) {
 	preState, err := state_native.InitializeFromProtoUnsafePhase0(&ethpb.BeaconState{})
 	require.NoError(t, err)
 	eth1Data := &ethpb.Eth1Data{}
-	for i := 0; i < 1000; i++ {
+	for range 1000 {
 		fuzzer.Fuzz(&genesisTime)
 		fuzzer.Fuzz(eth1Data)
 		fuzzer.Fuzz(preState)
@@ -60,7 +60,7 @@ func TestIsValidGenesisState_100000(_ *testing.T) {
 	fuzzer := fuzz.NewWithSeed(0)
 	fuzzer.NilChance(0.1)
 	var chainStartDepositCount, currentTime uint64
-	for i := 0; i < 100000; i++ {
+	for range 100000 {
 		fuzzer.Fuzz(&chainStartDepositCount)
 		fuzzer.Fuzz(&currentTime)
 		IsValidGenesisState(chainStartDepositCount, currentTime)

beacon-chain/core/transition/transition_fuzz_test.go

@@ -21,7 +21,7 @@ func TestFuzzExecuteStateTransition_1000(t *testing.T) {
 	sb := &ethpb.SignedBeaconBlock{}
 	fuzzer := fuzz.NewWithSeed(0)
 	fuzzer.NilChance(0.1)
-	for i := 0; i < 1000; i++ {
+	for range 1000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(sb)
 		if sb.Block == nil || sb.Block.Body == nil {
@@ -45,7 +45,7 @@ func TestFuzzCalculateStateRoot_1000(t *testing.T) {
 	sb := &ethpb.SignedBeaconBlock{}
 	fuzzer := fuzz.NewWithSeed(0)
 	fuzzer.NilChance(0.1)
-	for i := 0; i < 1000; i++ {
+	for range 1000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(sb)
 		if sb.Block == nil || sb.Block.Body == nil {
@@ -68,7 +68,7 @@ func TestFuzzProcessSlot_1000(t *testing.T) {
 	require.NoError(t, err)
 	fuzzer := fuzz.NewWithSeed(0)
 	fuzzer.NilChance(0.1)
-	for i := 0; i < 1000; i++ {
+	for range 1000 {
 		fuzzer.Fuzz(state)
 		s, err := ProcessSlot(ctx, state)
 		if err != nil && s != nil {
@@ -86,7 +86,7 @@ func TestFuzzProcessSlots_1000(t *testing.T) {
 	slot := primitives.Slot(0)
 	fuzzer := fuzz.NewWithSeed(0)
 	fuzzer.NilChance(0.1)
-	for i := 0; i < 1000; i++ {
+	for range 1000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(&slot)
 		s, err := ProcessSlots(ctx, state, slot)
@@ -105,7 +105,7 @@ func TestFuzzprocessOperationsNoVerify_1000(t *testing.T) {
 	bb := &ethpb.BeaconBlock{}
 	fuzzer := fuzz.NewWithSeed(0)
 	fuzzer.NilChance(0.1)
-	for i := 0; i < 1000; i++ {
+	for range 1000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(bb)
 		if bb.Body == nil {
@@ -128,7 +128,7 @@ func TestFuzzverifyOperationLengths_10000(t *testing.T) {
 	bb := &ethpb.BeaconBlock{}
 	fuzzer := fuzz.NewWithSeed(0)
 	fuzzer.NilChance(0.1)
-	for i := 0; i < 10000; i++ {
+	for range 10000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(bb)
 		if bb.Body == nil {
@@ -148,7 +148,7 @@ func TestFuzzCanProcessEpoch_10000(t *testing.T) {
 	require.NoError(t, err)
 	fuzzer := fuzz.NewWithSeed(0)
 	fuzzer.NilChance(0.1)
-	for i := 0; i < 10000; i++ {
+	for range 10000 {
 		fuzzer.Fuzz(state)
 		time.CanProcessEpoch(state)
 	}
@@ -162,7 +162,7 @@ func TestFuzzProcessEpochPrecompute_1000(t *testing.T) {
 	require.NoError(t, err)
 	fuzzer := fuzz.NewWithSeed(0)
 	fuzzer.NilChance(0.1)
-	for i := 0; i < 1000; i++ {
+	for range 1000 {
 		fuzzer.Fuzz(state)
 		s, err := ProcessEpochPrecompute(ctx, state)
 		if err != nil && s != nil {
@@ -180,7 +180,7 @@ func TestFuzzProcessBlockForStateRoot_1000(t *testing.T) {
 	sb := &ethpb.SignedBeaconBlock{}
 	fuzzer := fuzz.NewWithSeed(0)
 	fuzzer.NilChance(0.1)
-	for i := 0; i < 1000; i++ {
+	for range 1000 {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(sb)
 		if sb.Block == nil || sb.Block.Body == nil || sb.Block.Body.Eth1Data == nil {

beacon-chain/core/transition/transition_test.go

@@ -754,8 +754,7 @@ func BenchmarkProcessSlots_Capella(b *testing.B) {
 
 	var err error
 
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		st, err = transition.ProcessSlots(b.Context(), st, st.Slot()+1)
 		if err != nil {
 			b.Fatalf("Failed to process slot %v", err)
@@ -768,8 +767,7 @@ func BenchmarkProcessSlots_Deneb(b *testing.B) {
 
 	var err error
 
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		st, err = transition.ProcessSlots(b.Context(), st, st.Slot()+1)
 		if err != nil {
 			b.Fatalf("Failed to process slot %v", err)
@@ -782,8 +780,7 @@ func BenchmarkProcessSlots_Electra(b *testing.B) {
 
 	var err error
 
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		st, err = transition.ProcessSlots(b.Context(), st, st.Slot()+1)
 		if err != nil {
 			b.Fatalf("Failed to process slot %v", err)

beacon-chain/core/validators/validator.go

@@ -307,7 +307,7 @@ func SlashValidator(
 // ActivatedValidatorIndices determines the indices activated during the given epoch.
 func ActivatedValidatorIndices(epoch primitives.Epoch, validators []*ethpb.Validator) []primitives.ValidatorIndex {
 	activations := make([]primitives.ValidatorIndex, 0)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		val := validators[i]
 		if val.ActivationEpoch <= epoch && epoch < val.ExitEpoch {
 			activations = append(activations, primitives.ValidatorIndex(i))
@@ -319,7 +319,7 @@ func ActivatedValidatorIndices(epoch primitives.Epoch, validators []*ethpb.Valid
 // SlashedValidatorIndices determines the indices slashed during the given epoch.
 func SlashedValidatorIndices(epoch primitives.Epoch, validators []*ethpb.Validator) []primitives.ValidatorIndex {
 	slashed := make([]primitives.ValidatorIndex, 0)
-	for i := 0; i < len(validators); i++ {
+	for i := range validators {
 		val := validators[i]
 		maxWithdrawableEpoch := primitives.MaxEpoch(val.WithdrawableEpoch, epoch+params.BeaconConfig().EpochsPerSlashingsVector)
 		if val.WithdrawableEpoch == maxWithdrawableEpoch && val.Slashed {

beacon-chain/core/validators/validator_test.go

@@ -172,7 +172,7 @@ func TestSlashValidator_OK(t *testing.T) {
 	validatorCount := 100
 	registry := make([]*ethpb.Validator, 0, validatorCount)
 	balances := make([]uint64, 0, validatorCount)
-	for i := 0; i < validatorCount; i++ {
+	for range validatorCount {
 		registry = append(registry, &ethpb.Validator{
 			ActivationEpoch:  0,
 			ExitEpoch:        params.BeaconConfig().FarFutureEpoch,
@@ -226,7 +226,7 @@ func TestSlashValidator_Electra(t *testing.T) {
 	validatorCount := 100
 	registry := make([]*ethpb.Validator, 0, validatorCount)
 	balances := make([]uint64, 0, validatorCount)
-	for i := 0; i < validatorCount; i++ {
+	for range validatorCount {
 		registry = append(registry, &ethpb.Validator{
 			ActivationEpoch:  0,
 			ExitEpoch:        params.BeaconConfig().FarFutureEpoch,

beacon-chain/das/BUILD.bazel

@@ -4,14 +4,19 @@ go_library(
     name = "go_default_library",
     srcs = [
         "availability_blobs.go",
+        "availability_columns.go",
+        "bisect.go",
         "blob_cache.go",
         "data_column_cache.go",
         "iface.go",
+        "log.go",
         "mock.go",
+        "needs.go",
     ],
     importpath = "github.com/OffchainLabs/prysm/v7/beacon-chain/das",
     visibility = ["//visibility:public"],
     deps = [
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/db/filesystem:go_default_library",
         "//beacon-chain/verification:go_default_library",
         "//config/fieldparams:go_default_library",
@@ -21,6 +26,7 @@ go_library(
         "//runtime/logging:go_default_library",
         "//runtime/version:go_default_library",
         "//time/slots:go_default_library",
+        "@com_github_ethereum_go_ethereum//p2p/enode:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
     ],
@@ -30,11 +36,14 @@ go_test(
     name = "go_default_test",
     srcs = [
         "availability_blobs_test.go",
+        "availability_columns_test.go",
         "blob_cache_test.go",
         "data_column_cache_test.go",
+        "needs_test.go",
     ],
     embed = [":go_default_library"],
     deps = [
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/db/filesystem:go_default_library",
         "//beacon-chain/verification:go_default_library",
         "//config/fieldparams:go_default_library",
@@ -45,6 +54,7 @@ go_test(
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
         "//time/slots:go_default_library",
+        "@com_github_ethereum_go_ethereum//p2p/enode:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
     ],
 )

beacon-chain/das/availability_blobs.go

@@ -11,9 +11,8 @@ import (
 	"github.com/OffchainLabs/prysm/v7/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v7/runtime/logging"
 	"github.com/OffchainLabs/prysm/v7/runtime/version"
-	"github.com/OffchainLabs/prysm/v7/time/slots"
 	"github.com/pkg/errors"
-	log "github.com/sirupsen/logrus"
+	"github.com/sirupsen/logrus"
 )
 
 var (
@@ -24,12 +23,13 @@ var (
 // This implementation will hold any blobs passed to Persist until the IsDataAvailable is called for their
 // block, at which time they will undergo full verification and be saved to the disk.
 type LazilyPersistentStoreBlob struct {
-	store    *filesystem.BlobStorage
-	cache    *blobCache
-	verifier BlobBatchVerifier
+	store        *filesystem.BlobStorage
+	cache        *blobCache
+	verifier     BlobBatchVerifier
+	shouldRetain RetentionChecker
 }
 
-var _ AvailabilityStore = &LazilyPersistentStoreBlob{}
+var _ AvailabilityChecker = &LazilyPersistentStoreBlob{}
 
 // BlobBatchVerifier enables LazyAvailabilityStore to manage the verification process
 // going from ROBlob->VerifiedROBlob, while avoiding the decision of which individual verifications
@@ -42,11 +42,12 @@ type BlobBatchVerifier interface {
 
 // NewLazilyPersistentStore creates a new LazilyPersistentStore. This constructor should always be used
 // when creating a LazilyPersistentStore because it needs to initialize the cache under the hood.
-func NewLazilyPersistentStore(store *filesystem.BlobStorage, verifier BlobBatchVerifier) *LazilyPersistentStoreBlob {
+func NewLazilyPersistentStore(store *filesystem.BlobStorage, verifier BlobBatchVerifier, shouldRetain RetentionChecker) *LazilyPersistentStoreBlob {
 	return &LazilyPersistentStoreBlob{
-		store:    store,
-		cache:    newBlobCache(),
-		verifier: verifier,
+		store:        store,
+		cache:        newBlobCache(),
+		verifier:     verifier,
+		shouldRetain: shouldRetain,
 	}
 }
 
@@ -66,9 +67,6 @@ func (s *LazilyPersistentStoreBlob) Persist(current primitives.Slot, sidecars ..
 			}
 		}
 	}
-	if !params.WithinDAPeriod(slots.ToEpoch(sidecars[0].Slot()), slots.ToEpoch(current)) {
-		return nil
-	}
 	key := keyFromSidecar(sidecars[0])
 	entry := s.cache.ensure(key)
 	for _, blobSidecar := range sidecars {
@@ -81,8 +79,17 @@ func (s *LazilyPersistentStoreBlob) Persist(current primitives.Slot, sidecars ..
 
 // IsDataAvailable returns nil if all the commitments in the given block are persisted to the db and have been verified.
 // BlobSidecars already in the db are assumed to have been previously verified against the block.
-func (s *LazilyPersistentStoreBlob) IsDataAvailable(ctx context.Context, current primitives.Slot, b blocks.ROBlock) error {
-	blockCommitments, err := commitmentsToCheck(b, current)
+func (s *LazilyPersistentStoreBlob) IsDataAvailable(ctx context.Context, current primitives.Slot, blks ...blocks.ROBlock) error {
+	for _, b := range blks {
+		if err := s.checkOne(ctx, current, b); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (s *LazilyPersistentStoreBlob) checkOne(ctx context.Context, current primitives.Slot, b blocks.ROBlock) error {
+	blockCommitments, err := commitmentsToCheck(b, s.shouldRetain)
 	if err != nil {
 		return errors.Wrapf(err, "could not check data availability for block %#x", b.Root())
 	}
@@ -100,7 +107,7 @@ func (s *LazilyPersistentStoreBlob) IsDataAvailable(ctx context.Context, current
 	// Verify we have all the expected sidecars, and fail fast if any are missing or inconsistent.
 	// We don't try to salvage problematic batches because this indicates a misbehaving peer and we'd rather
 	// ignore their response and decrease their peer score.
-	sidecars, err := entry.filter(root, blockCommitments, b.Block().Slot())
+	sidecars, err := entry.filter(root, blockCommitments)
 	if err != nil {
 		return errors.Wrap(err, "incomplete BlobSidecar batch")
 	}
@@ -112,7 +119,7 @@ func (s *LazilyPersistentStoreBlob) IsDataAvailable(ctx context.Context, current
 		ok := errors.As(err, &me)
 		if ok {
 			fails := me.Failures()
-			lf := make(log.Fields, len(fails))
+			lf := make(logrus.Fields, len(fails))
 			for i := range fails {
 				lf[fmt.Sprintf("fail_%d", i)] = fails[i].Error()
 			}
@@ -131,13 +138,12 @@ func (s *LazilyPersistentStoreBlob) IsDataAvailable(ctx context.Context, current
 	return nil
 }
 
-func commitmentsToCheck(b blocks.ROBlock, current primitives.Slot) ([][]byte, error) {
+func commitmentsToCheck(b blocks.ROBlock, shouldRetain RetentionChecker) ([][]byte, error) {
 	if b.Version() < version.Deneb {
 		return nil, nil
 	}
 
-	// We are only required to check within MIN_EPOCHS_FOR_BLOB_SIDECARS_REQUEST
-	if !params.WithinDAPeriod(slots.ToEpoch(b.Block().Slot()), slots.ToEpoch(current)) {
+	if !shouldRetain(b.Block().Slot()) {
 		return nil, nil
 	}
 

beacon-chain/das/availability_blobs_test.go

@@ -17,6 +17,10 @@ import (
 	errors "github.com/pkg/errors"
 )
 
+func testShouldRetainAlways(s primitives.Slot) bool {
+	return true
+}
+
 func Test_commitmentsToCheck(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
 	params.BeaconConfig().FuluForkEpoch = params.BeaconConfig().ElectraForkEpoch + 4096*2
@@ -26,15 +30,16 @@ func Test_commitmentsToCheck(t *testing.T) {
 	windowSlots = windowSlots + primitives.Slot(params.BeaconConfig().FuluForkEpoch)
 	maxBlobs := params.LastNetworkScheduleEntry().MaxBlobsPerBlock
 	commits := make([][]byte, maxBlobs+1)
-	for i := 0; i < len(commits); i++ {
+	for i := range commits {
 		commits[i] = bytesutil.PadTo([]byte{byte(i)}, 48)
 	}
 	cases := []struct {
-		name    string
-		commits [][]byte
-		block   func(*testing.T) blocks.ROBlock
-		slot    primitives.Slot
-		err     error
+		name         string
+		commits      [][]byte
+		block        func(*testing.T) blocks.ROBlock
+		slot         primitives.Slot
+		err          error
+		shouldRetain RetentionChecker
 	}{
 		{
 			name: "pre deneb",
@@ -60,6 +65,7 @@ func Test_commitmentsToCheck(t *testing.T) {
 				require.NoError(t, err)
 				return rb
 			},
+			shouldRetain: testShouldRetainAlways,
 			commits: func() [][]byte {
 				mb := params.GetNetworkScheduleEntry(slots.ToEpoch(fulu + 100)).MaxBlobsPerBlock
 				return commits[:mb]
@@ -79,7 +85,8 @@ func Test_commitmentsToCheck(t *testing.T) {
 				require.NoError(t, err)
 				return rb
 			},
-			slot: fulu + windowSlots + 1,
+			shouldRetain: func(s primitives.Slot) bool { return false },
+			slot:         fulu + windowSlots + 1,
 		},
 		{
 			name: "excessive commitments",
@@ -97,14 +104,15 @@ func Test_commitmentsToCheck(t *testing.T) {
 				require.Equal(t, true, len(c) > params.BeaconConfig().MaxBlobsPerBlock(sb.Block().Slot()))
 				return rb
 			},
-			slot: windowSlots + 1,
-			err:  errIndexOutOfBounds,
+			shouldRetain: testShouldRetainAlways,
+			slot:         windowSlots + 1,
+			err:          errIndexOutOfBounds,
 		},
 	}
 	for _, c := range cases {
 		t.Run(c.name, func(t *testing.T) {
 			b := c.block(t)
-			co, err := commitmentsToCheck(b, c.slot)
+			co, err := commitmentsToCheck(b, c.shouldRetain)
 			if c.err != nil {
 				require.ErrorIs(t, err, c.err)
 			} else {
@@ -126,7 +134,7 @@ func TestLazilyPersistent_Missing(t *testing.T) {
 	blk, blobSidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, ds, 3)
 
 	mbv := &mockBlobBatchVerifier{t: t, scs: blobSidecars}
-	as := NewLazilyPersistentStore(store, mbv)
+	as := NewLazilyPersistentStore(store, mbv, testShouldRetainAlways)
 
 	// Only one commitment persisted, should return error with other indices
 	require.NoError(t, as.Persist(ds, blobSidecars[2]))
@@ -153,7 +161,7 @@ func TestLazilyPersistent_Mismatch(t *testing.T) {
 
 	mbv := &mockBlobBatchVerifier{t: t, err: errors.New("kzg check should not run")}
 	blobSidecars[0].KzgCommitment = bytesutil.PadTo([]byte("nope"), 48)
-	as := NewLazilyPersistentStore(store, mbv)
+	as := NewLazilyPersistentStore(store, mbv, testShouldRetainAlways)
 
 	// Only one commitment persisted, should return error with other indices
 	require.NoError(t, as.Persist(ds, blobSidecars[0]))
@@ -166,11 +174,11 @@ func TestLazyPersistOnceCommitted(t *testing.T) {
 	ds := util.SlotAtEpoch(t, params.BeaconConfig().DenebForkEpoch)
 	_, blobSidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, ds, 6)
 
-	as := NewLazilyPersistentStore(filesystem.NewEphemeralBlobStorage(t), &mockBlobBatchVerifier{})
+	as := NewLazilyPersistentStore(filesystem.NewEphemeralBlobStorage(t), &mockBlobBatchVerifier{}, testShouldRetainAlways)
 	// stashes as expected
 	require.NoError(t, as.Persist(ds, blobSidecars...))
 	// ignores duplicates
-	require.ErrorIs(t, as.Persist(ds, blobSidecars...), ErrDuplicateSidecar)
+	require.ErrorIs(t, as.Persist(ds, blobSidecars...), errDuplicateSidecar)
 
 	// ignores index out of bound
 	blobSidecars[0].Index = 6
@@ -183,7 +191,7 @@ func TestLazyPersistOnceCommitted(t *testing.T) {
 	require.NoError(t, as.Persist(slotOOB, moreBlobSidecars[0]))
 
 	// doesn't ignore new sidecars with a different block root
-	require.NoError(t, as.Persist(ds, moreBlobSidecars...))
+	require.NoError(t, as.Persist(ds, moreBlobSidecars[1:]...))
 }
 
 type mockBlobBatchVerifier struct {

beacon-chain/das/availability_columns.go

@@ -0,0 +1,244 @@
+package das
+
+import (
+	"context"
+	"io"
+
+	"github.com/OffchainLabs/prysm/v7/beacon-chain/core/peerdas"
+	"github.com/OffchainLabs/prysm/v7/beacon-chain/db/filesystem"
+	"github.com/OffchainLabs/prysm/v7/beacon-chain/verification"
+	"github.com/OffchainLabs/prysm/v7/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v7/consensus-types/primitives"
+	"github.com/ethereum/go-ethereum/p2p/enode"
+	errors "github.com/pkg/errors"
+)
+
+// LazilyPersistentStoreColumn is an implementation of AvailabilityStore to be used when batch syncing data columns.
+// This implementation will hold any data columns passed to Persist until the IsDataAvailable is called for their
+// block, at which time they will undergo full verification and be saved to the disk.
+type LazilyPersistentStoreColumn struct {
+	store                  *filesystem.DataColumnStorage
+	cache                  *dataColumnCache
+	newDataColumnsVerifier verification.NewDataColumnsVerifier
+	custody                *custodyRequirement
+	bisector               Bisector
+	shouldRetain           RetentionChecker
+}
+
+var _ AvailabilityChecker = &LazilyPersistentStoreColumn{}
+
+// DataColumnsVerifier enables LazilyPersistentStoreColumn to manage the verification process
+// going from RODataColumn->VerifiedRODataColumn, while avoiding the decision of which individual verifications
+// to run and in what order. Since LazilyPersistentStoreColumn always tries to verify and save data columns only when
+// they are all available, the interface takes a slice of data column sidecars.
+type DataColumnsVerifier interface {
+	VerifiedRODataColumns(ctx context.Context, blk blocks.ROBlock, scs []blocks.RODataColumn) ([]blocks.VerifiedRODataColumn, error)
+}
+
+// NewLazilyPersistentStoreColumn creates a new LazilyPersistentStoreColumn.
+// WARNING: The resulting LazilyPersistentStoreColumn is NOT thread-safe.
+func NewLazilyPersistentStoreColumn(
+	store *filesystem.DataColumnStorage,
+	newDataColumnsVerifier verification.NewDataColumnsVerifier,
+	nodeID enode.ID,
+	cgc uint64,
+	bisector Bisector,
+	shouldRetain RetentionChecker,
+) *LazilyPersistentStoreColumn {
+	return &LazilyPersistentStoreColumn{
+		store:                  store,
+		cache:                  newDataColumnCache(),
+		newDataColumnsVerifier: newDataColumnsVerifier,
+		custody:                &custodyRequirement{nodeID: nodeID, cgc: cgc},
+		bisector:               bisector,
+		shouldRetain:           shouldRetain,
+	}
+}
+
+// PersistColumns adds columns to the working column cache. Columns stored in this cache will be persisted
+// for at least as long as the node is running. Once IsDataAvailable succeeds, all columns referenced
+// by the given block are guaranteed to be persisted for the remainder of the retention period.
+func (s *LazilyPersistentStoreColumn) Persist(_ primitives.Slot, sidecars ...blocks.RODataColumn) error {
+	for _, sidecar := range sidecars {
+		if err := s.cache.stash(sidecar); err != nil {
+			return errors.Wrap(err, "stash DataColumnSidecar")
+		}
+	}
+
+	return nil
+}
+
+// IsDataAvailable returns nil if all the commitments in the given block are persisted to the db and have been verified.
+// DataColumnsSidecars already in the db are assumed to have been previously verified against the block.
+func (s *LazilyPersistentStoreColumn) IsDataAvailable(ctx context.Context, _ primitives.Slot, blks ...blocks.ROBlock) error {
+	toVerify := make([]blocks.RODataColumn, 0)
+	for _, block := range blks {
+		indices, err := s.required(block)
+		if err != nil {
+			return errors.Wrapf(err, "full commitments to check with block root `%#x`", block.Root())
+		}
+		if indices.Count() == 0 {
+			continue
+		}
+
+		key := keyFromBlock(block)
+		entry := s.cache.entry(key)
+		toVerify, err = entry.append(toVerify, IndicesNotStored(s.store.Summary(block.Root()), indices))
+		if err != nil {
+			return errors.Wrap(err, "entry filter")
+		}
+	}
+
+	if err := s.verifyAndSave(toVerify); err != nil {
+		log.Warn("Batch verification failed, bisecting columns by peer")
+		if err := s.bisectVerification(toVerify); err != nil {
+			return errors.Wrap(err, "bisect verification")
+		}
+	}
+
+	s.cache.cleanup(blks)
+	return nil
+}
+
+// required returns the set of column indices to check for a given block.
+func (s *LazilyPersistentStoreColumn) required(block blocks.ROBlock) (peerdas.ColumnIndices, error) {
+	if !s.shouldRetain(block.Block().Slot()) {
+		return peerdas.NewColumnIndices(), nil
+	}
+
+	// If there are any commitments in the block, there are blobs,
+	// and if there are blobs, we need the columns bisecting those blobs.
+	commitments, err := block.Block().Body().BlobKzgCommitments()
+	if err != nil {
+		return nil, errors.Wrap(err, "blob KZG commitments")
+	}
+	// No DA check needed if the block has no blobs.
+	if len(commitments) == 0 {
+		return peerdas.NewColumnIndices(), nil
+	}
+
+	return s.custody.required()
+}
+
+// verifyAndSave calls Save on the column store if the columns pass verification.
+func (s *LazilyPersistentStoreColumn) verifyAndSave(columns []blocks.RODataColumn) error {
+	if len(columns) == 0 {
+		return nil
+	}
+	verified, err := s.verifyColumns(columns)
+	if err != nil {
+		return errors.Wrap(err, "verify columns")
+	}
+	if err := s.store.Save(verified); err != nil {
+		return errors.Wrap(err, "save data column sidecars")
+	}
+
+	return nil
+}
+
+func (s *LazilyPersistentStoreColumn) verifyColumns(columns []blocks.RODataColumn) ([]blocks.VerifiedRODataColumn, error) {
+	if len(columns) == 0 {
+		return nil, nil
+	}
+	verifier := s.newDataColumnsVerifier(columns, verification.ByRangeRequestDataColumnSidecarRequirements)
+	if err := verifier.ValidFields(); err != nil {
+		return nil, errors.Wrap(err, "valid fields")
+	}
+	if err := verifier.SidecarInclusionProven(); err != nil {
+		return nil, errors.Wrap(err, "sidecar inclusion proven")
+	}
+	if err := verifier.SidecarKzgProofVerified(); err != nil {
+		return nil, errors.Wrap(err, "sidecar KZG proof verified")
+	}
+
+	return verifier.VerifiedRODataColumns()
+}
+
+// bisectVerification is used when verification of a batch of columns fails. Since the batch could
+// span multiple blocks or have been fetched from multiple peers, this pattern enables code using the
+// store to break the verification into smaller units and learn the results, in order to plan to retry
+// retrieval of the unusable columns.
+func (s *LazilyPersistentStoreColumn) bisectVerification(columns []blocks.RODataColumn) error {
+	if len(columns) == 0 {
+		return nil
+	}
+	if s.bisector == nil {
+		return errors.New("bisector not initialized")
+	}
+	iter, err := s.bisector.Bisect(columns)
+	if err != nil {
+		return errors.Wrap(err, "Bisector.Bisect")
+	}
+	// It's up to the bisector how to chunk up columns for verification,
+	// which could be by block, or by peer, or any other strategy.
+	// For the purposes of range syncing or backfill this will be by peer,
+	// so that the node can learn which peer is giving us bad data and downscore them.
+	for columns, err := iter.Next(); columns != nil; columns, err = iter.Next() {
+		if err != nil {
+			if !errors.Is(err, io.EOF) {
+				return errors.Wrap(err, "Bisector.Next")
+			}
+			break // io.EOF signals end of iteration
+		}
+		// We save the parts of the batch that have been verified successfully even though we don't know
+		// if all columns for the block will be available until the block is imported.
+		if err := s.verifyAndSave(s.columnsNotStored(columns)); err != nil {
+			iter.OnError(err)
+			continue
+		}
+	}
+	// This should give us a single error representing any unresolved errors seen via onError.
+	return iter.Error()
+}
+
+// columnsNotStored filters the list of ROColumnSidecars to only include those that are not found in the storage summary.
+func (s *LazilyPersistentStoreColumn) columnsNotStored(sidecars []blocks.RODataColumn) []blocks.RODataColumn {
+	// We use this method to filter a set of sidecars that were previously seen to be unavailable on disk. So our base assumption
+	// is that they are still available and we don't need to copy the list. Instead we make a slice of any indices that are unexpectedly
+	// stored and only when we find that the storage view has changed do we need to create a new slice.
+	stored := make(map[int]struct{}, 0)
+	lastRoot := [32]byte{}
+	var sum filesystem.DataColumnStorageSummary
+	for i, sc := range sidecars {
+		if sc.BlockRoot() != lastRoot {
+			sum = s.store.Summary(sc.BlockRoot())
+			lastRoot = sc.BlockRoot()
+		}
+		if sum.HasIndex(sc.Index) {
+			stored[i] = struct{}{}
+		}
+	}
+	// If the view on storage hasn't changed, return the original list.
+	if len(stored) == 0 {
+		return sidecars
+	}
+	shift := 0
+	for i := range sidecars {
+		if _, ok := stored[i]; ok {
+			// If the index is stored, skip and overwrite it.
+			// Track how many spaces down to shift unseen sidecars (to overwrite the previously shifted or seen).
+			shift++
+			continue
+		}
+		if shift > 0 {
+			// If the index is not stored and we have seen stored indices,
+			// we need to shift the current index down.
+			sidecars[i-shift] = sidecars[i]
+		}
+	}
+	return sidecars[:len(sidecars)-shift]
+}
+
+type custodyRequirement struct {
+	nodeID  enode.ID
+	cgc     uint64 // custody group count
+	indices peerdas.ColumnIndices
+}
+
+func (c *custodyRequirement) required() (peerdas.ColumnIndices, error) {
+	peerInfo, _, err := peerdas.Info(c.nodeID, c.cgc)
+	if err != nil {
+		return peerdas.NewColumnIndices(), errors.Wrap(err, "peer info")
+	}
+	return peerdas.NewColumnIndicesFromMap(peerInfo.CustodyColumns), nil
+}