VC: Fix getBlockRoot() response with execution_optimistic. (#4622)

* Fix getStateRoot() and getBlockRoot() API functions which should obtain `execution_optimistic` field.
Fix sync committee service to check `execution_optimistic` field of getBlockRoot() response.

* 2nd part.

* Remove presets usage.

beacon_chain/spec/eth2_apis/eth2_rest_serialization.nim

@@ -132,7 +132,9 @@ type
     Web3SignerErrorResponse |
     Web3SignerKeysResponse |
     Web3SignerSignatureResponse |
-    Web3SignerStatusResponse
+    Web3SignerStatusResponse |
+    GetStateRootResponse |
+    GetBlockRootResponse
 
   RestVersioned*[T] = object
     data*: T

beacon_chain/spec/eth2_apis/rest_types.nim

@@ -613,6 +613,10 @@ type
   RestRoot* = object
     root*: Eth2Digest
 
+  DataRestRoot* = object
+    execution_optimistic*: Option[bool]
+    data*: RestRoot
+
   # Types based on the OAPI yaml file - used in responses to requests
   GetBeaconHeadResponse* = DataEnclosedObject[Slot]
   GetAggregatedAttestationResponse* = DataEnclosedObject[Attestation]
@@ -620,7 +624,7 @@ type
   GetBlockAttestationsResponse* = DataEnclosedObject[seq[Attestation]]
   GetBlockHeaderResponse* = DataEnclosedObject[RestBlockHeaderInfo]
   GetBlockHeadersResponse* = DataEnclosedObject[seq[RestBlockHeaderInfo]]
-  GetBlockRootResponse* = DataEnclosedObject[RestRoot]
+  GetBlockRootResponse* = DataRestRoot
   GetDebugChainHeadsResponse* = DataEnclosedObject[seq[RestChainHead]]
   GetDepositContractResponse* = DataEnclosedObject[RestDepositContract]
   GetDepositSnapshotResponse* = DataEnclosedObject[RestDepositSnapshot]
@@ -641,7 +645,7 @@ type
   GetSpecVCResponse* = DataEnclosedObject[RestSpecVC]
   GetStateFinalityCheckpointsResponse* = DataEnclosedObject[RestBeaconStatesFinalityCheckpoints]
   GetStateForkResponse* = DataEnclosedObject[Fork]
-  GetStateRootResponse* = DataEnclosedObject[RestRoot]
+  GetStateRootResponse* = DataRestRoot
   GetStateValidatorBalancesResponse* = DataEnclosedObject[seq[RestValidatorBalance]]
   GetStateValidatorResponse* = DataEnclosedObject[RestValidator]
   GetStateValidatorsResponse* = DataEnclosedObject[seq[RestValidator]]

beacon_chain/validator_client/api.nim

@@ -895,7 +895,7 @@ proc getForkSchedule*(
 proc getHeadBlockRoot*(
        vc: ValidatorClientRef,
        strategy: ApiStrategyKind
-     ): Future[RestRoot] {.async.} =
+     ): Future[DataRestRoot] {.async.} =
   logScope:
     request = "getHeadBlockRoot"
     strategy = $strategy
@@ -937,7 +937,7 @@ proc getHeadBlockRoot*(
           RestBeaconNodeStatus.Offline
     if res.isErr():
       raise newException(ValidatorApiError, res.error())
-    return res.get().data.data
+    return res.get().data
 
   of ApiStrategyKind.Priority:
     vc.firstSuccessSequential(RestResponse[GetBlockRootResponse], SlotDuration,
@@ -951,7 +951,7 @@ proc getHeadBlockRoot*(
         case response.status
         of 200:
           trace ResponseSuccess, endpoint = node
-          return response.data.data
+          return response.data
         of 400:
           debug ResponseInvalidError, response_code = response.status,
                 endpoint = node

beacon_chain/validator_client/sync_committee_service.nim

@@ -348,7 +348,19 @@ proc publishSyncMessagesAndContributions(service: SyncCommitteeServiceRef,
     block:
       try:
         let res = await vc.getHeadBlockRoot(ApiStrategyKind.First)
-        res.root
+        if res.execution_optimistic.isNone():
+          ## The `execution_optimistic` is missing from the response, we assume
+          ## that the BN is unaware optimistic sync, so we consider the BN
+          ## to be synchronized with the network.
+          ## TODO (cheatfate): This should be removed when VC will be able to
+          ## handle getSpec() API call with fork constants.
+          res.data.root
+        else:
+          if res.execution_optimistic.get():
+            error "Could not obtain head block's root because beacon node " &
+                  "only optimistically synced", slot = slot
+            return
+          res.data.root
       except ValidatorApiError as exc:
         error "Unable to retrieve head block's root to sign", reason = exc.msg
         return