fix: remove aggregation bits from seen attestation cache

packages/beacon-node/src/chain/opPools/attestationPool.ts

@@ -109,7 +109,7 @@ export class AttestationPool {
     committeeIndex: CommitteeIndex,
     attestation: SingleAttestation,
     attDataRootHex: RootHex,
-    aggregationBits: BitArray | null
+    aggregationBits: BitArray
   ): InsertOutcome {
     const slot = attestation.data.slot;
     const fork = this.config.getForkName(slot);
@@ -224,7 +224,7 @@ export class AttestationPool {
 function aggregateAttestationInto(
   aggregate: AggregateFast,
   attestation: SingleAttestation,
-  aggregationBits: BitArray | null
+  aggregationBits: BitArray
 ): InsertOutcome {
   let bitIndex: number | null;
 
@@ -250,7 +250,7 @@ function aggregateAttestationInto(
 /**
  * Format `contribution` into an efficient `aggregate` to add more contributions in with aggregateContributionInto()
  */
-function attestationToAggregate(attestation: SingleAttestation, aggregationBits: BitArray | null): AggregateFast {
+function attestationToAggregate(attestation: SingleAttestation, aggregationBits: BitArray): AggregateFast {
   if (isElectraSingleAttestation(attestation)) {
     assert.notNull(aggregationBits, "aggregationBits missing post-electra to generate aggregate");
     return {

packages/beacon-node/src/chain/seenCache/seenAttestationData.ts

@@ -11,7 +11,6 @@ type AttDataBase64 = string;
 export type AttestationDataCacheEntry = {
   // part of shuffling data, so this does not take memory
   committeeValidatorIndices: Uint32Array;
-  // TODO: remove this? this is available in SingleAttestation
   committeeIndex: CommitteeIndex;
   // IndexedAttestationData signing root, 32 bytes
   signingRoot: Uint8Array;
@@ -21,8 +20,6 @@ export type AttestationDataCacheEntry = {
   // for example in a mainnet node subscribing to all subnets, attestations are processed up to 20k per slot
   attestationData: phase0.AttestationData;
   subnet: number;
-  // aggregationBits only populates post-electra. Pre-electra can use get it directly from attestationOrBytes
-  aggregationBits: BitArray | null;
 };
 
 export enum RejectReason {

packages/beacon-node/src/chain/validation/attestation.ts

@@ -69,7 +69,7 @@ export type AttestationValidationResult = {
   subnet: number;
   attDataRootHex: RootHex;
   committeeIndex: CommitteeIndex;
-  aggregationBits: BitArray | null; // Field populated post-electra only
+  aggregationBits: BitArray;
 };
 
 export type AttestationOrBytes = ApiAttestation | GossipAttestation;
@@ -344,11 +344,6 @@ async function validateAttestationNoSignatureCheck(
         code: AttestationErrorCode.NOT_EXACTLY_ONE_AGGREGATION_BIT_SET,
       });
     }
-  } else {
-    // Populate aggregationBits if cached post-electra, else we populate later
-    if (attestationOrCache.cache && attestationOrCache.cache.aggregationBits !== null) {
-      aggregationBits = attestationOrCache.cache.aggregationBits;
-    }
   }
 
   let committeeValidatorIndices: Uint32Array;
@@ -423,18 +418,15 @@ async function validateAttestationNoSignatureCheck(
     validatorIndex = (attestationOrCache.attestation as SingleAttestation<ForkPostElectra>).attesterIndex;
     // [REJECT] The attester is a member of the committee -- i.e.
     // `attestation.attester_index in get_beacon_committee(state, attestation.data.slot, index)`.
-    // If `aggregationBitsElectra` exists, that means we have already cached it. No need to check again
-    if (aggregationBits === null) {
-      // Position of the validator in its committee
-      const committeeValidatorIndex = committeeValidatorIndices.indexOf(validatorIndex);
-      if (committeeValidatorIndex === -1) {
-        throw new AttestationError(GossipAction.REJECT, {
-          code: AttestationErrorCode.ATTESTER_NOT_IN_COMMITTEE,
-        });
-      }
-
-      aggregationBits = BitArray.fromSingleBit(committeeValidatorIndices.length, committeeValidatorIndex);
+    // Position of the validator in its committee
+    const committeeValidatorIndex = committeeValidatorIndices.indexOf(validatorIndex);
+    if (committeeValidatorIndex === -1) {
+      throw new AttestationError(GossipAction.REJECT, {
+        code: AttestationErrorCode.ATTESTER_NOT_IN_COMMITTEE,
+      });
     }
+
+    aggregationBits = BitArray.fromSingleBit(committeeValidatorIndices.length, committeeValidatorIndex);
   }
 
   // LH > verify_middle_checks
@@ -504,7 +496,6 @@ async function validateAttestationNoSignatureCheck(
         // root of AttestationData was already cached during getIndexedAttestationSignatureSet
         attDataRootHex,
         attestationData: attData,
-        aggregationBits: isForkPostElectra(fork) ? aggregationBits : null,
       });
     }
   }
@@ -540,7 +531,7 @@ async function validateAttestationNoSignatureCheck(
     signatureSet,
     validatorIndex,
     committeeIndex,
-    aggregationBits: isForkPostElectra(fork) ? aggregationBits : null,
+    aggregationBits,
   };
 }