assertr 0.5.6

Fluent assertions for the Rust programming language.
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
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131

use crate::{AssertThat, Mode, tracking::AssertionTracking};
use core::fmt::Debug;
use indoc::writedoc;
use std::fmt::Write;
use tokio::sync::Mutex;

// TODO: Add possibility to easily assert on the contained value (when the lock can be acquired).
/// Assertions for tokio's [Mutex] type.
#[allow(clippy::return_self_not_must_use)]
#[cfg_attr(feature = "fluent", assertr_derive::fluent_aliases)]
pub trait TokioMutexAssertions<T: Debug> {
    fn is_locked(self) -> Self;

    #[cfg_attr(feature = "fluent", fluent_alias("not_be_locked"))]
    fn is_not_locked(self) -> Self;

    fn is_free(self) -> Self
    where
        Self: Sized,
    {
        self.is_not_locked()
    }
}

impl<T: Debug, M: Mode> TokioMutexAssertions<T> for AssertThat<'_, Mutex<T>, M> {
    #[track_caller]
    fn is_locked(self) -> Self {
        self.track_assertion();
        let actual = self.actual();
        if let Ok(guard) = actual.try_lock() {
            self.fail(|w: &mut String| {
                writedoc! {w, r"
                    Expected: Mutex {{ data: {guard:#?} }}

                    to be locked, but it wasn't!
                "}
            });
        }
        self
    }

    #[track_caller]
    fn is_not_locked(self) -> Self {
        self.track_assertion();
        let actual = self.actual();
        if let Err(_err) = actual.try_lock() {
            self.fail(|w: &mut String| {
                writedoc! {w, r"
                    Expected: Mutex {{ data: <locked> }}

                    to not be locked, but it was!
                "}
            });
        }
        self
    }
}

#[cfg(test)]
mod tests {

    mod is_locked {
        use indoc::formatdoc;
        use tokio::sync::Mutex;

        use crate::prelude::*;

        #[tokio::test]
        async fn succeeds_when_locked() {
            let mutex = Mutex::new(42);
            let guard = mutex.lock().await;
            assert_that!(&mutex).is_locked();
            drop(guard);
        }

        #[test]
        fn panics_when_not_locked() {
            let mutex = Mutex::new(42);
            assert_that_panic_by(|| assert_that!(mutex).with_location(false).is_locked())
                .has_type::<String>()
                .is_equal_to(formatdoc! {"
                    -------- assertr --------
                    Expected: Mutex {{ data: 42 }}

                    to be locked, but it wasn't!
                    -------- assertr --------
                "});
        }
    }

    mod is_not_locked {
        use indoc::formatdoc;
        use tokio::sync::Mutex;

        use crate::prelude::*;

        #[test]
        fn succeeds_when_not_locked() {
            let mutex = Mutex::new(42);
            assert_that!(mutex).is_not_locked();
        }

        #[tokio::test]
        async fn panics_when_locked() {
            let mutex = Mutex::new(42);
            let guard = mutex.lock().await;
            assert_that_panic_by(|| assert_that!(&mutex).with_location(false).is_not_locked())
                .has_type::<String>()
                .is_equal_to(formatdoc! {"
                    -------- assertr --------
                    Expected: Mutex {{ data: <locked> }}

                    to not be locked, but it was!
                    -------- assertr --------
                "});
            drop(guard);
        }
    }

    mod is_free {
        use tokio::sync::Mutex;

        use crate::prelude::*;

        #[test]
        fn succeeds_when_not_locked() {
            let mutex = Mutex::new(42);
            assert_that!(mutex).is_free();
        }
    }
}