feat: attestation index=1 requires FULL variant (consensus-specs#4918)

packages/fork-choice/src/forkChoice/errors.ts

@@ -57,6 +57,10 @@ export enum InvalidAttestationCode {
    * The attestation data index is invalid for a Gloas block (must be 0 or 1).
    */
   INVALID_DATA_INDEX = "INVALID_DATA_INDEX",
+  /**
+   * Attestation index=1 (full node) but the payload is not known/available.
+   */
+  UNKNOWN_PAYLOAD_STATUS = "UNKNOWN_PAYLOAD_STATUS",
 }
 
 export type InvalidAttestation =
@@ -69,7 +73,8 @@ export type InvalidAttestation =
   | {code: InvalidAttestationCode.INVALID_TARGET; attestation: RootHex; local: RootHex}
   | {code: InvalidAttestationCode.ATTESTS_TO_FUTURE_BLOCK; block: Slot; attestation: Slot}
   | {code: InvalidAttestationCode.FUTURE_SLOT; attestationSlot: Slot; latestPermissibleSlot: Slot}
-  | {code: InvalidAttestationCode.INVALID_DATA_INDEX; index: number};
+  | {code: InvalidAttestationCode.INVALID_DATA_INDEX; index: number}
+  | {code: InvalidAttestationCode.UNKNOWN_PAYLOAD_STATUS; beaconBlockRoot: RootHex};
 
 export enum ForkChoiceErrorCode {
   INVALID_ATTESTATION = "FORKCHOICE_ERROR_INVALID_ATTESTATION",

packages/fork-choice/src/forkChoice/forkChoice.ts

@@ -1673,6 +1673,22 @@ export class ForkChoice implements IForkChoice {
       });
     }
 
+    // [New in Gloas:EIP7732]
+    // If attesting for a full node (index=1), the payload must be known (locally available)
+    // Spec: gloas/fork-choice.md#modified-validate_on_attestation
+    if (isGloasBlock(block) && attestationData.index === 1) {
+      const fullVariant = this.protoArray.getNodeIndexByRootAndStatus(beaconBlockRootHex, PayloadStatus.FULL);
+      if (fullVariant === undefined) {
+        throw new ForkChoiceError({
+          code: ForkChoiceErrorCode.INVALID_ATTESTATION,
+          err: {
+            code: InvalidAttestationCode.UNKNOWN_PAYLOAD_STATUS,
+            beaconBlockRoot: beaconBlockRootHex,
+          },
+        });
+      }
+    }
+
     this.validatedAttestationDatas.add(attDataRoot);
   }