# CronCat errors macro
This package creates a procedural attribute macro that creates `#[croncat_error]`, intended to be placed above the integrating contract's error enum, which is conventionally called `ContractError`.
**Note**: this macro should go above the usual `Derive` we see for this enum. The correct placement looks like this:
```rs
#[croncat_error]
#[derive(Error, Debug, PartialEq)]
pub enum ContractError {
// variants here…
}
```
It will throw a compile-time error if it is not placed correctly.
The macro adds this enum variant:
```rs
#[error("CronCat error: {err:?}")]
CronCatError {
err: CronCatContractError
}
```
It also adds this logic:
```rs
impl From<CronCatContractError> for ContractError {
fn from(error: CronCatContractError) -> Self {
ContractError::CronCatError {
err: error,
}
}
}
```
The above logic will allow helper functions in `croncat-integration-utils` to propagate errors in a manner consistent with the contract's errors.