[go: up one dir, main page]

anyhow 1.0.3

A better Box<dyn Error>
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
59
60
61
62
63

use anyhow::{bail, ensure, Result};
use std::io;

fn bail_literal() -> Result<()> {
    bail!("oh no!");
}

fn bail_fmt() -> Result<()> {
    bail!("{} {}!", "oh", "no");
}

fn bail_error() -> Result<()> {
    bail!(io::Error::new(io::ErrorKind::Other, "oh no!"));
}

#[test]
fn test_messages() {
    assert_eq!("oh no!", bail_literal().unwrap_err().to_string());
    assert_eq!("oh no!", bail_fmt().unwrap_err().to_string());
    assert_eq!("oh no!", bail_error().unwrap_err().to_string());
}

#[test]
fn test_downcast() {
    assert_eq!(
        "oh no!",
        bail_literal().unwrap_err().downcast::<&str>().unwrap(),
    );
    assert_eq!(
        "oh no!",
        bail_fmt().unwrap_err().downcast::<String>().unwrap(),
    );
    assert_eq!(
        "oh no!",
        bail_error()
            .unwrap_err()
            .downcast::<io::Error>()
            .unwrap()
            .to_string(),
    );
}

#[test]
fn test_ensure() {
    let f = || {
        ensure!(1 + 1 == 2, "This is correct");
        Ok(())
    };
    assert!(f().is_ok());

    let v = 1;
    let f = || {
        ensure!(v + v == 2, "This is correct, v: {}", v);
        Ok(())
    };
    assert!(f().is_ok());

    let f = || {
        ensure!(v + v == 1, "This is not correct, v: {}", v);
        Ok(())
    };
    assert!(f().is_err());
}