From 723c7c885df9c2d44a3fc50ca340f5106897d30c Mon Sep 17 00:00:00 2001
From: victor felder <victor@draft.li>
Date: Thu, 10 Oct 2024 14:41:28 +0200
Subject: [PATCH] fix(rpc): add error handling

---
 lib/rpc.ex        | 33 ++++++++++++++++++++++-----------
 test/rpc_test.exs |  2 +-
 2 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/lib/rpc.ex b/lib/rpc.ex
index 08ff9fc..0acd258 100644
--- a/lib/rpc.ex
+++ b/lib/rpc.ex
@@ -200,18 +200,24 @@ defmodule Tezex.Rpc do
   @doc """
   Sign the forged operation and returns the forged operation+signature payload to be injected.
   """
-  @spec forge_and_sign_operation(operation(), encoded_private_key()) :: nonempty_binary()
+  @spec forge_and_sign_operation(operation(), encoded_private_key()) ::
+          {:ok, nonempty_binary()} | {:error, nonempty_binary()}
   def forge_and_sign_operation(operation, encoded_private_key) do
-    {:ok, forged_operation} = ForgeOperation.operation_group(operation)
+    case ForgeOperation.operation_group(operation) do
+      {:ok, forged_operation} ->
+        signature = Crypto.sign_operation(encoded_private_key, forged_operation)
 
-    signature = Crypto.sign_operation(encoded_private_key, forged_operation)
+        payload_signature =
+          signature
+          |> Crypto.decode_signature!()
+          |> Base.encode16(case: :lower)
 
-    payload_signature =
-      signature
-      |> Crypto.decode_signature!()
-      |> Base.encode16(case: :lower)
+        signed_payload = forged_operation <> payload_signature
+        {:ok, signed_payload}
 
-    forged_operation <> payload_signature
+      err ->
+        err
+    end
   end
 
   @doc """
@@ -223,10 +229,15 @@ defmodule Tezex.Rpc do
           | {:error, Jason.DecodeError.t()}
           | {:error, term()}
   def preapply_operation(%Rpc{} = rpc, operation, encoded_private_key, protocol) do
-    {:ok, forged_operation} = ForgeOperation.operation_group(operation)
-    signature = Crypto.sign_operation(encoded_private_key, forged_operation)
-    payload = [Map.merge(operation, %{"signature" => signature, "protocol" => protocol})]
+    with {:ok, forged_operation} <- ForgeOperation.operation_group(operation),
+         signature = Crypto.sign_operation(encoded_private_key, forged_operation),
+         payload = [Map.merge(operation, %{"signature" => signature, "protocol" => protocol})],
+         {:ok, preapplied_operations} <- do_preapply_operation(rpc, payload) do
+      {:ok, preapplied_operations}
+    end
+  end
 
+  defp do_preapply_operation(%Rpc{} = rpc, payload) do
     case post(rpc, "/blocks/head/helpers/preapply/operations", payload) do
       {:ok, [%{"contents" => preapplied_operations}]} ->
         applied? =
diff --git a/test/rpc_test.exs b/test/rpc_test.exs
index 4794356..b911ae9 100644
--- a/test/rpc_test.exs
+++ b/test/rpc_test.exs
@@ -75,7 +75,7 @@ defmodule Tezex.RpcTest do
     result =
       "6940b2318870c4b84862aef187c1bbcd4138170459e85092fe34be5d179f40ac6c00980d7cebb50d4b83a4e3307b3ca1b40ebe8f71ab00e308ab0b8102640000b75f0c30536bee108b068d90b151ce846aca11b1009bc207291f08c7117ea3a341328a036ce7bd5da996d9148cc491f96c3097748d7adcdb60599504ae5227aea4a6e69d536baaf96ae2bbb6c261a69d000b323f0a"
 
-    assert result == Rpc.forge_and_sign_operation(operation, @ghostnet_1_pkey)
+    assert {:ok, result} == Rpc.forge_and_sign_operation(operation, @ghostnet_1_pkey)
   end
 
   describe "fill_operation_fee/3" do