#error #deprecated #diagnostics #annotate #information #path #info

yanked error-annotation

DEPRECATED: use anyhow instead

0.1.4 Apr 8, 2023
0.1.3 Jan 31, 2022
0.1.2 Jan 31, 2022
0.1.1 Jan 31, 2022
0.1.0 Jan 31, 2022

#9 in #annotate

30 downloads per month
Used in pathutil

MIT license

13KB
195 lines

DEPRECATED

Use anyhow instead.

Old info

Annotate errors with diagnostic information.

The API docs are currently the only documentation.


lib.rs:

Add useful diagnostic information to error values as they propagate.

Annotatable Error Types

The most ergonomic usage is available for types that implement Annotatable via the AnnotateResult::annotate_err_into method, which is implemented for Result. In this case, diagnostic annotations can be built up without altering the resulting error types. An example using the std::io::Error impl of Annotatable clarifies these ergonomics:

Example: Chaining Diagnostic Annotations on std::io::Error

use std::path::{Path, PathBuf};
use std::fs::Metadata;
use error_annotation::{AnnotateResult, ErrorAnnotation};

fn annotated_copy(src: &Path, dst: &Path) -> std::io::Result<u64> {
  std::fs::copy(src, dst)
    .annotate_err_into("source", || src.display())
    .annotate_err_into("destination", || dst.display())
}

let badsource = PathBuf::from("/this/path/does/not/exist");
let dest = PathBuf::from("/tmp/woah-dude");
let res = annotated_copy(&badsource, &dest);
let err = res.err().unwrap();

assert_eq!(&err.to_string(), "

No such file or directory (os error 2)
-with source: /this/path/does/not/exist
-with destination: /tmp/woah-dude

".trim());

Annotating Other Error Types

It is still possible to annotate an arbitrary error type T which does not implement Annotatable with annotation info type I by way of the ErrorAnnotation parameterized type. The downside being each annotation corresponds to a different parameterization, ie ErrorAnnotation<T, I>, which propagates out of interfaces and must be explicitly handled by consuming code.

No runtime deps