Fluffy: Implement debug_callByStateRoot RPC endpoint (#3186)

Author: bhartnett

fluffy/rpc/rpc_calls/rpc_debug_calls.nim

@@ -1,5 +1,5 @@
 # fluffy
-# Copyright (c) 2021-2024 Status Research & Development GmbH
+# Copyright (c) 2021-2025 Status Research & Development GmbH
 # Licensed and distributed under either of
 #   * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
 #   * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
@@ -19,3 +19,10 @@ createRpcSigsFromNim(RpcClient):
   ): FixedBytes[32]
 
   proc debug_getCodeByStateRoot(data: Address, stateRoot: Hash32): seq[byte]
+  proc debug_getProofByStateRoot(
+    address: Address, slots: seq[UInt256], stateRoot: Hash32
+  ): ProofResponse
+
+  proc debug_callByStateRoot(
+    tx: TransactionArgs, stateRoot: Hash32, blockId: Opt[BlockIdentifier]
+  ): seq[byte]

fluffy/rpc/rpc_calls/rpc_eth_calls.nim

@@ -47,3 +47,5 @@ createRpcSigsFromNim(RpcClient):
   proc eth_getProof(
     address: Address, slots: seq[UInt256], blockId: BlockIdentifier
   ): ProofResponse
+
+  proc eth_call(tx: TransactionArgs, blockId: BlockIdentifier): seq[byte]

fluffy/rpc/rpc_debug_api.nim

@@ -11,14 +11,27 @@ import
   json_rpc/rpcserver,
   chronicles,
   web3/[eth_api_types, conversions],
-  ../network/state/state_endpoints
+  ../network/state/state_endpoints,
+  ../evm/[async_evm, async_evm_portal_backend]
 
 template getOrRaise(stateNetwork: Opt[StateNetwork]): StateNetwork =
   let sn = stateNetwork.valueOr:
     raise newException(ValueError, "state sub-network not enabled")
   sn
 
+template getOrRaise(asyncEvm: Opt[AsyncEvm]): AsyncEvm =
+  let evm = asyncEvm.valueOr:
+    raise
+      newException(ValueError, "portal evm requires state sub-network to be enabled")
+  evm
+
 proc installDebugApiHandlers*(rpcServer: RpcServer, stateNetwork: Opt[StateNetwork]) =
+  let asyncEvm =
+    if stateNetwork.isSome():
+      Opt.some(AsyncEvm.init(stateNetwork.get().toAsyncEvmStateBackend()))
+    else:
+      Opt.none(AsyncEvm)
+
   rpcServer.rpc("debug_getBalanceByStateRoot") do(
     address: Address, stateRoot: Hash32
   ) -> UInt256:
@@ -120,3 +133,37 @@ proc installDebugApiHandlers*(rpcServer: RpcServer, stateNetwork: Opt[StateNetwo
       storageHash: proofs.account.storageRoot,
       storageProof: storageProof,
     )
+
+  rpcServer.rpc("debug_callByStateRoot") do(
+    tx: TransactionArgs,
+    stateRoot: Hash32,
+    quantityTag: Opt[RtBlockIdentifier],
+    optimisticStateFetch: Opt[bool]
+  ) -> seq[byte]:
+    # TODO: add documentation
+
+    # This endpoint can be used to test eth_call without requiring the history network
+    # to be enabled. This is useful for scenarios where we don't yet have the block headers
+    # seeded into the history network.
+
+    if tx.to.isNone():
+      raise newException(ValueError, "to address is required")
+
+    let quantityTag = quantityTag.valueOr:
+      blockId(0.uint64)
+    if quantityTag.kind == bidAlias:
+      raise newException(ValueError, "tag not yet implemented")
+
+    let
+      evm = asyncEvm.getOrRaise()
+      header = Header(stateRoot: stateRoot, number: quantityTag.number.uint64)
+      optimisticStateFetch = optimisticStateFetch.valueOr:
+        true
+
+    let callResult = (await evm.call(header, tx, optimisticStateFetch)).valueOr:
+      raise newException(ValueError, error)
+
+    if callResult.error.len() > 0:
+      raise newException(ValueError, callResult.error)
+
+    callResult.output

fluffy/rpc/rpc_eth_api.nim

@@ -448,17 +448,10 @@ proc installEthApiHandlers*(
       evm = asyncEvm.getOrRaise()
       header = (await hn.getVerifiedBlockHeader(quantityTag.number.uint64)).valueOr:
         raise newException(ValueError, "Unable to get block header")
+      optimisticStateFetch = optimisticStateFetch.valueOr:
+        true
 
-    let callResult = (
-      await evm.call(
-        header,
-        tx,
-        if optimisticStateFetch.isNone():
-          true
-        else:
-          optimisticStateFetch.get(),
-      )
-    ).valueOr:
+    let callResult = (await evm.call(header, tx, optimisticStateFetch)).valueOr:
       raise newException(ValueError, error)
 
     if callResult.error.len() > 0: