Trait ErrorChainExt

Source

pub trait ErrorChainExt {
    // Required methods
    fn chain(&self) -> Chain<'_> ⓘ;
    fn root_cause(&self) -> &(dyn StdError + 'static);
}

Expand description

Walk an error and its source chain.

Import via use oopsie::prelude::* or use oopsie::ErrorChainExt.

Implemented for every E: Error + 'static and for dyn Error + 'static itself, so it covers a typed #[oopsie] error, a Welp, and the &(dyn Error + 'static) returned by source with a single method call.

§Example

use oopsie::{Oopsie, ErrorChainExt as _, ResultExt as _};

#[derive(Debug, Oopsie)]
#[oopsie(module(false))]
enum ReadError {
    #[oopsie("read failed: {source}")]
    Read { source: std::io::Error },
}

let err: Result<(), std::io::Error> = Err(std::io::Error::other("disk full"));
let err = err.context(Read).unwrap_err();

let messages: Vec<String> = err.chain().map(ToString::to_string).collect();
assert_eq!(messages, ["read failed: disk full", "disk full"]);
assert_eq!(err.root_cause().to_string(), "disk full");