Bug: calldata format error when proxying deploy transactions

[xJonathanLEI]

Description

When forwarding DEPLOY transactions to the sequencer gateway, the node incorrectly encodes constructor_calldata elements as hex strings, while the sequencer actually expects decimal representations.

(Let's take a moment to appreciate the inconsistencies in the gateway APIs lol)

This inconsistency is taken care of in starknet-rs:

#[serde_as]
#[derive(Debug, Serialize)]
pub struct DeployTransaction {
    pub constructor_calldata: Vec<FieldElement>,
    #[serde_as(as = "UfeHex")]
    pub contract_address_salt: FieldElement,
    pub contract_definition: ContractDefinition,
}

(FieldElement serializes as decimal representation by default, so without serde_as on constructor_calldata it just uses decimal.)

Steps to reproduce

Send this request to a running node (adding in abi because of #369):

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "starknet_addDeployTransaction",
  "params": [
    "0x1",
    ["0x2"],
    {
      "abi": [],
      "entry_points_by_type": {
        "CONSTRUCTOR": [],
        "EXTERNAL": [],
        "L1_HANDLER": []
      },
      "program": "____INSERT_VALID_PROGRAM_CODE_HERE____"
    }
  ]
}

Expected result

Transaction can be successfully submitted.

Actual result

Transaction submission fails with:

{
  "jsonrpc": "2.0",
  "error": {
    "code": -32000,
    "message": "StarknetError { code: MalformedRequest, message: \"{'constructor_calldata': {0: ['Expected int string, got: \\\"0x2\\\".']}}\" }"
  },
  "id": 1
}

[CHr15F0x]

Hmm looks like we forgot to add #[serde_as(as = "Vec<ConstructorParamAsDecimalStr>")] to the very field.
Thanks for spotting 🙏 .