erc20/library.cairo "Transfer" event param "_from" not compatible with Starknet Python testing library

📝 Details

with Starkware official testing Python package: starkware/starknet/testing/contract_utils.py line 100, it encodes processed StarknetTransaction with namedtuple. Thus, calling erc20 Transfer with current OZ event signature

@event
func Transfer(_from : felt, to : felt, value : Uint256):
end

will fail with ValueError: Field names cannot start with an underscore: '_from'

🔢 Code to reproduce bug

In Python, try calling Transfer with this pattern tx = await erc20_contract.transfer(10, dst.contract_address).invoke(src) given

• erc20_contract = erc20 contract
• src = source account contract
• dst = destination account contract

[martriay]

Yeah, that’s fair. I suppose ugly is better than potentially confusing.

Agree. Luckily argument names are not part of Ethereum’s ABI specification, so it shouldn’t break anything. I’m unsure about the events though.

Let’s go with from_ then.

[milancermak]

To me, that looks too much like a type name (when compared to Uint256), but that’s just my opinion.