Function option_contract 

pub fn option_contract(
    symbol: &str,
    last_trade_date: &str,
    strike: f64,
    right: &str,
    exchange: &str,
    currency: &str,
) -> Result<Contract, ContractConfigError>

Build an options contract.

Errors

Returns ContractConfigError::UnrecognizedOptionRight if right is not one of C/CALL/P/PUT (case-insensitive; leading and trailing whitespace is ignored). An option contract is invalid without a valid right, so this is surfaced at construction rather than as a later IBKR submission rejection.

Only right is validated here. last_trade_date and strike are forwarded to the IBKR contract as-is; an empty date or a 0.0 strike will build a (quietly wrong) contract. Presence of those fields is checked one level up in ContractConfig::to_contract, which is the intended entry point for config-driven construction.