zerror 0.9.0

zerror provides an error interface for context-aware error-reporting.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58

use std::fmt::Debug;

use zerror::{Z, iotoz};

#[derive(Debug)]
pub struct SampleError {
    err: std::io::Error,
    var: Vec<String>,
}

impl From<std::io::Error> for SampleError {
    fn from(err: std::io::Error) -> Self {
        Self {
            err,
            var: Vec::new(),
        }
    }
}

impl Z for SampleError {
    type Error = Self;

    fn long_form(&self) -> String {
        "long form".to_owned()
    }

    fn with_info<X: Debug>(mut self, name: &str, value: X) -> Self::Error {
        self.var.push(format!("{name}: {value:?}"));
        self
    }

    fn with_lazy_info<F: FnOnce() -> String>(mut self, name: &str, value: F) -> Self::Error {
        self.var.push(format!("{}: {:?}", name, value()));
        self
    }
}

iotoz!(SampleError);

#[test]
fn sample_error() {
    let success: Result<(), std::io::Error> = Ok(());
    let failure: Result<(), std::io::Error> =
        Err(std::io::Error::new(std::io::ErrorKind::NotFound, "message"));

    let success: Result<(), SampleError> = success.as_z();
    let failure: Result<(), SampleError> = failure.as_z();

    let success = success.with_info("TOKEN", 42);
    assert!(success.is_ok());

    let failure = failure.with_info("TOKEN", 42);
    assert!(failure.is_err());
    if let Err(err) = failure {
        assert_eq!(vec!["TOKEN: 42"], err.var);
        assert_eq!("message", format!("{}", err.err));
    }
}