refactor(starknet_api): serialize chain_id as felt (#6140)

Author: nimrod-starkware

crates/starknet_api/src/core.rs

@@ -7,6 +7,7 @@ use std::sync::LazyLock;
 
 use num_traits::ToPrimitive;
 use primitive_types::H160;
+use serde::de::Error;
 use serde::{Deserialize, Deserializer, Serialize, Serializer};
 use size_of::SizeOf;
 use starknet_types_core::felt::{Felt, NonZeroFelt};
@@ -85,6 +86,22 @@ impl ChainId {
     }
 }
 
+pub fn deserialize_chain_id_from_hex<'de, D>(deserializer: D) -> Result<ChainId, D::Error>
+where
+    D: Deserializer<'de>,
+{
+    let hex_str = String::deserialize(deserializer)?;
+    let chain_id_str =
+        std::str::from_utf8(&hex::decode(hex_str.trim_start_matches("0x")).map_err(|e| {
+            D::Error::custom(format!("Failed to decode the hex string {hex_str}. Error: {:?}", e))
+        })?)
+        .map_err(|e| {
+            D::Error::custom(format!("Failed to convert to UTF-8 string. Error: {:?}", e))
+        })?
+        .to_string();
+    Ok(ChainId::from(chain_id_str))
+}
+
 /// The address of a contract, used for example in [StateDiff](`crate::state::StateDiff`),
 /// [DeclareTransaction](`crate::transaction::DeclareTransaction`), and
 /// [BlockHeader](`crate::block::BlockHeader`).

crates/starknet_os/src/io/os_input.rs

@@ -1,10 +1,17 @@
 use std::collections::HashMap;
 
 use cairo_lang_starknet_classes::casm_contract_class::CasmContractClass;
-use serde::{Deserialize, Serialize};
+use serde::Serialize;
 use shared_execution_objects::central_objects::CentralTransactionExecutionInfo;
 use starknet_api::block::{BlockHash, BlockInfo, BlockNumber};
-use starknet_api::core::{ChainId, ClassHash, CompiledClassHash, ContractAddress, Nonce};
+use starknet_api::core::{
+    deserialize_chain_id_from_hex,
+    ChainId,
+    ClassHash,
+    CompiledClassHash,
+    ContractAddress,
+    Nonce,
+};
 use starknet_api::deprecated_contract_class::ContractClass;
 use starknet_api::executable_transaction::Transaction;
 use starknet_api::state::StorageKey;
@@ -69,8 +76,10 @@ pub struct StarknetOsInput {
 }
 
 // TODO(Meshi): Remove Once the blockifier ChainInfo do not support deprecated fee token.
-#[derive(Clone, Debug, Deserialize, PartialEq, Serialize)]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+#[derive(Clone, Debug, PartialEq, Serialize)]
 pub struct OsChainInfo {
+    #[cfg_attr(feature = "deserialize", serde(deserialize_with = "deserialize_chain_id_from_hex"))]
     pub(crate) chain_id: ChainId,
     pub(crate) strk_fee_token_address: ContractAddress,
 }