dyn-error 0.2.0

Error-related utilites for Rust
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# dyn-error

_Error-related utilites for Rust_

[![CI](https://github.com/giancosta86/dyn-error/actions/workflows/publish-to-crates.yml/badge.svg)](https://github.com/giancosta86/dyn-error/actions/workflows/publish-to-crates.yml)
![Crates.io Version](https://img.shields.io/crates/v/dyn-error?style=flat&logo=rust)

This crate provides error-related utilities.

In particular, the `check_err_box` function
can test an `Err` result wrapping a `Box` with an `Error` implementation,
using equality test via `PartialEq`:

```rust
use dyn_error::*;
use std::fmt::Display;
use std::error::Error;

//
// Declaring a custom Error type
//
#[derive(Debug, PartialEq, Eq)]
struct MyErr(pub u8);

impl Display for MyErr {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "Custom error: {}", self.0)
    }
}

impl Error for MyErr {};

// Declaring a Result that can hold any Error implementation
let mut result: Result<String, Box<dyn Error>>;

//
// Test scenarios
//
result = Err(Box::new(MyErr(90)));
assert_eq!(
    check_err_box(result, MyErr(90)),
    Ok(())
);

result = Err(Box::new(MyErr(90)));
assert_eq!(
    check_err_box(result, MyErr(7)),
    Err(ErrBoxCheckFailure::NotEqual {
        expected: "Custom error: 7".to_string(),
        actual: "Custom error: 90".to_string()
    })
);
```

For more details - including different `Error`
taxonomies, please refer to `check_err_box`.

You can simplify the check even more, by using the panic-based
`assert_err_box` macro:

```rust
use dyn_error::*;
use std::fmt::Display;
use std::error::Error;

#[derive(Debug, PartialEq, Eq)]
struct MyErr(pub u8);

impl Display for MyErr {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "Custom error: {}", self.0)
    }
}

impl Error for MyErr {};

let result: Result<String, Box<dyn Error>> = Err(Box::new(MyErr(90)));

assert_err_box!(result, MyErr(90));
```

## Crates.io

https://crates.io/crates/dyn-error

## Documentation

https://docs.rs/dyn-error

## License

[MIT](LICENSE)