Best practices for handling my own errors and openbrush's errors?

Question

• I am using ink! to implement the contract.
• I have implemented my own error, and the contract function has this own error as a return value.
• For example, suppose that function implements openbrush's Ownable.
• I implemented openbrush's Error implementation as follows.
• What would be the best way to implement it then?
• Referenced source code:https://github.com/Supercolony-net/openbrush-contracts/blob/main/contracts/src/traits/errors/psp37.rs

    #[derive(Debug, PartialEq, Eq, scale::Encode, scale::Decode)]
    #[cfg_attr(feature = "std", derive(scale_info::TypeInfo))]
    pub enum MyError {
        MyError1,
        OwnableErrorCallerIsNotOwner,
        OwnableErrorNewOwnerIsZero,
    }
    impl From<OwnableError> for MyError {
        fn from(ownable: OwnableError) -> Self {
            match ownable {
                OwnableError::CallerIsNotOwner => MyError::OwnableErrorCallerIsNotOwner,
                OwnableError::NewOwnerIsZero => MyError::OwnableErrorNewOwnerIsZero,
            }
        }
    } 

Answer 1

The best way is to have an enum field that will encapsulate the Ownable error, and implement the From trait for it:

#[derive(Debug, PartialEq, Eq, scale::Encode, scale::Decode)]
#[cfg_attr(feature = "std", derive(scale_info::TypeInfo))]
pub enum MyError {
    OwnableError(OwnableError)
    MyError1,
}

impl From<OwnableError> for MyError {
    fn from(error: OwnableError) -> Self {
        MyError::OwnableError(error)
    }
}

example here