implement graphql.Query.account

although this is not part of EIP 1767
but the hive test cases derived from besu
test cases contains this.
we add this now to pass more test hive.graphql cases

nimbus/graphql/ethapi.nim

@@ -590,6 +590,9 @@ proc txCreatedContract(ud: RootRef, params: Args, parent: Node): RespResult {.ap
   let tx = TxNode(parent)
   var sender: EthAddress
   if not getSender(tx.tx, sender):
+    return err("can't calculate sender")
+
+  if not tx.tx.isContractCreation:
     return ok(respNull())
 
   let hres = getBlockByNumber(ctx, tx.blockNumber)
@@ -929,6 +932,22 @@ const pendingProcs = {
   "estimateGas": pendingEstimateGas
 }
 
+proc pickBlockNumber(ctx: GraphqlContextRef, number: Node): BlockNumber =
+  if number.kind == nkEmpty:
+    ctx.chainDB.highestBlock
+  else:
+    parseU64(number).toBlockNumber
+
+proc queryAccount(ud: RootRef, params: Args, parent: Node): RespResult {.apiPragma.} =
+  let ctx = GraphqlContextRef(ud)
+  let address = hexToByteArray[20](params[0].val.stringVal)
+  let blockNumber = pickBlockNumber(ctx, params[1].val)
+  let hres = getBlockByNumber(ctx, blockNumber)
+  if hres.isErr:
+    return hres
+  let h = HeaderNode(hres.get())
+  accountNode(ctx, h.header, address)
+
 proc queryBlock(ud: RootRef, params: Args, parent: Node): RespResult {.apiPragma.} =
   let ctx = GraphqlContextRef(ud)
   let number = params[0].val
@@ -947,10 +966,7 @@ proc queryBlocks(ud: RootRef, params: Args, parent: Node): RespResult {.apiPragm
   let fromNumber = parseU64(params[0].val).toBlockNumber
 
   let to = params[1].val
-  let toNumber = if to.kind == nkEmpty:
-                   ctx.chainDB.highestBlock
-                 else:
-                   parseU64(to).toBlockNumber
+  let toNumber = pickBlockNumber(ctx, to)
 
   if fromNumber > toNumber:
     return err("from($1) is bigger than to($2)" % [fromNumber.toString, toNumber.toString])
@@ -1005,6 +1021,7 @@ proc querySyncing(ud: RootRef, params: Args, parent: Node): RespResult {.apiPrag
   ok(respMap(ctx.ids[ethSyncState]))
 
 const queryProcs = {
+  "account": queryAccount,
   "block": queryBlock,
   "blocks": queryBlocks,
   "pending": queryPending,

nimbus/graphql/ethapi.ql

@@ -345,6 +345,10 @@ type Pending {
 }
 
 type Query {
+  # Account fetches an Ethereum account at the specified block number.
+  # If blockNumber is not provided, it defaults to the most recent block.
+  account(address: Address!, blockNumber: Long): Account!
+
   # Block fetches an Ethereum block by number or by hash. If neither is
   # supplied, the most recent known block is returned.
   block(number: Long, hash: Bytes32): Block