error-rules 0.2.1

Error handling without pain
Documentation 
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use error_rules::*;


#[test]
fn test_error_kind_wo_arg() {
    #[derive(Debug, Error)]
    enum C0 {
        #[error_kind("custom")]
        Custom,
    }

    assert_eq!(C0::Custom.to_string().as_str(), "custom");
}


#[test]
fn test_error_kind_w1_arg() {
    #[derive(Debug, Error)]
    enum T1 {
        #[error_kind("custom:{}", 0)]
        Custom(usize),
    }

    assert_eq!(T1::Custom(100).to_string().as_str(), "custom:100");
}


#[test]
fn test_error_kind_w2_arg() {
    #[derive(Debug, Error)]
    enum T2 {
        #[error_kind("custom:{}:{}", 0, 1)]
        Custom(usize, usize),
    }

    assert_eq!(T2::Custom(100, 200).to_string().as_str(), "custom:100:200");
}


#[test]
fn test_error_from() {
    use std::io;

    #[derive(Debug, Error)]
    enum F {
        #[error_from("io:{}", 0)]
        Io(io::Error),
    }

    let e = F::Io(io::Error::from(io::ErrorKind::PermissionDenied));
    assert_eq!(e.to_string().as_str(), "io:permission denied");
    assert_eq!(std::error::Error::source(&e).unwrap().to_string().as_str(), "permission denied");
}