Add SingleAttestation container

.gitignore

@@ -17,5 +17,8 @@ coverage.html
 # Vim
 *.sw?
 
+# Intellij and friends
+.idea/
+
 # Local TODO
 TODO.md

spec/electra/generate.go

@@ -15,6 +15,6 @@ package electra
 
 //nolint:revive
 // Need to `go install github.com/ferranbt/fastssz/sszgen@latest` for this to work.
-//go:generate rm -f aggregateandproof_ssz.go attestation_ssz.go attesterslashing_ssz.go beaconblockbody_ssz.go beaconblock_ssz.go beaconstate_ssz.go consolidation_ssz.go consolidationrequest_ssz.go depositrequest_ssz.go withdrawalrequest_ssz.go executionrequests_ssz.go pendingconsolidation_ssz.go pendingdeposit_ssz.go pendingpartialwithdrawal_ssz.go signedaggregateandproof_ssz.go signedbeaconblock_ssz.go
-//go:generate sszgen --suffix=ssz --path . --include ../phase0,../altair,../bellatrix,../capella,../deneb --objs AggregateAndProof,Attestation,AttesterSlashing,BeaconBlockBody,BeaconBlock,BeaconState,Consolidation,ConsolidationRequest,DepositRequest,WithdrawalRequest,ExecutionRequests,PendingConsolidation,PendingDeposit,PendingPartialWithdrawal,SignedAggregateAndProof,SignedBeaconBlock
-//go:generate goimports -w aggregateandproof_ssz.go attestation_ssz.go attesterslashing_ssz.go beaconblockbody_ssz.go beaconblock_ssz.go beaconstate_ssz.go consolidation_ssz.go consolidationrequest_ssz.go depositrequest_ssz.go withdrawalrequest_ssz.go executionrequests_ssz.go pendingconsolidation_ssz.go pendingdeposit_ssz.go pendingpartialwithdrawal_ssz.go signedaggregateandproof_ssz.go signedbeaconblock_ssz.go
+//go:generate rm -f aggregateandproof_ssz.go attestation_ssz.go attesterslashing_ssz.go beaconblockbody_ssz.go beaconblock_ssz.go beaconstate_ssz.go consolidation_ssz.go consolidationrequest_ssz.go depositrequest_ssz.go withdrawalrequest_ssz.go executionrequests_ssz.go pendingconsolidation_ssz.go pendingdeposit_ssz.go pendingpartialwithdrawal_ssz.go signedaggregateandproof_ssz.go signedbeaconblock_ssz.go singleattestation_ssz.go
+//go:generate sszgen --suffix=ssz --path . --include ../phase0,../altair,../bellatrix,../capella,../deneb --objs AggregateAndProof,Attestation,AttesterSlashing,BeaconBlockBody,BeaconBlock,BeaconState,Consolidation,ConsolidationRequest,DepositRequest,WithdrawalRequest,ExecutionRequests,PendingConsolidation,PendingDeposit,PendingPartialWithdrawal,SignedAggregateAndProof,SignedBeaconBlock,SingleAttestation
+//go:generate goimports -w aggregateandproof_ssz.go attestation_ssz.go attesterslashing_ssz.go beaconblockbody_ssz.go beaconblock_ssz.go beaconstate_ssz.go consolidation_ssz.go consolidationrequest_ssz.go depositrequest_ssz.go withdrawalrequest_ssz.go executionrequests_ssz.go pendingconsolidation_ssz.go pendingdeposit_ssz.go pendingpartialwithdrawal_ssz.go signedaggregateandproof_ssz.go signedbeaconblock_ssz.go singleattestation_ssz.go

spec/electra/singleattestation.go

@@ -0,0 +1,40 @@
+// Copyright © 2024 Attestant Limited.
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package electra
+
+import (
+	"fmt"
+
+	"github.com/attestantio/go-eth2-client/spec/phase0"
+	"github.com/goccy/go-yaml"
+)
+
+// SingleAttestation is a new struct in electra for propagating network only Attestations. See:
+// https://github.com/ethereum/consensus-specs/blob/dev/specs/electra/beacon-chain.md#singleattestation.
+type SingleAttestation struct {
+	CommitteeIndex phase0.CommitteeIndex
+	AttesterIndex  phase0.ValidatorIndex
+	Data           *phase0.AttestationData
+	Signature      phase0.BLSSignature `ssz-size:"96"`
+}
+
+// String returns a string version of the structure.
+func (a *SingleAttestation) String() string {
+	data, err := yaml.Marshal(a)
+	if err != nil {
+		return fmt.Sprintf("ERR: %v", err)
+	}
+
+	return string(data)
+}

spec/electra/singleattestation_json.go

@@ -0,0 +1,91 @@
+// Copyright © 2024 Attestant Limited.
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package electra
+
+import (
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/attestantio/go-eth2-client/spec/phase0"
+	"github.com/pkg/errors"
+)
+
+// singleAttestationJSON is the spec representation of the struct.
+type singleAttestationJSON struct {
+	CommitteeIndex string                  `json:"committee_index"`
+	AttesterIndex  string                  `json:"attester_index"`
+	Data           *phase0.AttestationData `json:"data"`
+	Signature      string                  `json:"signature"`
+}
+
+// MarshalJSON implements json.Marshaler.
+func (a *SingleAttestation) MarshalJSON() ([]byte, error) {
+	return json.Marshal(&singleAttestationJSON{
+		CommitteeIndex: fmt.Sprintf("%d", a.CommitteeIndex),
+		AttesterIndex:  fmt.Sprintf("%d", a.AttesterIndex),
+		Data:           a.Data,
+		Signature:      fmt.Sprintf("%#x", a.Signature),
+	})
+}
+
+// UnmarshalJSON implements json.Unmarshaler.
+func (a *SingleAttestation) UnmarshalJSON(input []byte) error {
+	var singleAttestationJSON singleAttestationJSON
+	err := json.Unmarshal(input, &singleAttestationJSON)
+	if err != nil {
+		return errors.Wrap(err, "invalid JSON")
+	}
+
+	return a.unpack(&singleAttestationJSON)
+}
+
+func (a *SingleAttestation) unpack(singleAttestationJSON *singleAttestationJSON) error {
+	var err error
+	if singleAttestationJSON.CommitteeIndex == "" {
+		return errors.New("committee index missing")
+	}
+	committeeIndex, err := strconv.ParseUint(singleAttestationJSON.CommitteeIndex, 10, 64)
+	if err != nil {
+		return errors.Wrap(err, "invalid value for committee index")
+	}
+	a.CommitteeIndex = phase0.CommitteeIndex(committeeIndex)
+	if singleAttestationJSON.AttesterIndex == "" {
+		return errors.New("attester index missing")
+	}
+	attesterIndex, err := strconv.ParseUint(singleAttestationJSON.AttesterIndex, 10, 64)
+	if err != nil {
+		return errors.Wrap(err, "invalid value for attester index")
+	}
+	a.AttesterIndex = phase0.ValidatorIndex(attesterIndex)
+	a.Data = singleAttestationJSON.Data
+	if a.Data == nil {
+		return errors.New("data missing")
+	}
+	if singleAttestationJSON.Signature == "" {
+		return errors.New("signature missing")
+	}
+	signature, err := hex.DecodeString(strings.TrimPrefix(singleAttestationJSON.Signature, "0x"))
+	if err != nil {
+		return errors.Wrap(err, "invalid value for signature")
+	}
+	if len(signature) != phase0.SignatureLength {
+		return errors.New("incorrect length for signature")
+	}
+	copy(a.Signature[:], signature)
+
+	return nil
+}