Derive Macro Masterror 

#[derive(Masterror)]
{
    // Attributes available to this derive:
    #[error]
    #[source]
    #[from]
    #[backtrace]
    #[masterror]
    #[provide]
}

Re-export derive macros so users only depend on this crate.

The From<T> for AppError conversion generated by #[app_error(...)] attaches the domain error as the source of the produced AppError, keeping it downcastable and part of the error chain. Attaching requires T: Send + Sync + 'static; use the no_source flag to opt out and drop the domain error during conversion instead.

Examples

use masterror::{AppCode, AppError, AppErrorKind, Error};

#[derive(Debug, Error)]
#[error("missing flag: {name}")]
#[app_error(kind = AppErrorKind::BadRequest, code = AppCode::BadRequest, message)]
struct MissingFlag {
    name: &'static str
}

let app: AppError = MissingFlag {
    name: "feature"
}
.into();
assert!(matches!(app.kind, AppErrorKind::BadRequest));
assert!(app.downcast_ref::<MissingFlag>().is_some());

let code: AppCode = MissingFlag {
    name: "other"
}
.into();
assert_eq!(code, AppCode::BadRequest);