util.rs

 1#[cfg(any(test, feature = "test-support"))]
 2use std::time::Duration;
 3
 4#[cfg(any(test, feature = "test-support"))]
 5use futures::Future;
 6
 7#[cfg(any(test, feature = "test-support"))]
 8use smol::future::FutureExt;
 9
10pub use util::*;
11
12/// A helper trait for building complex objects with imperative conditionals in a fluent style.
13pub trait FluentBuilder {
14    /// Imperatively modify self with the given closure.
15    fn map<U>(self, f: impl FnOnce(Self) -> U) -> U
16    where
17        Self: Sized,
18    {
19        f(self)
20    }
21
22    /// Conditionally modify self with the given closure.
23    fn when(self, condition: bool, then: impl FnOnce(Self) -> Self) -> Self
24    where
25        Self: Sized,
26    {
27        self.map(|this| if condition { then(this) } else { this })
28    }
29
30    /// Conditionally unwrap and modify self with the given closure, if the given option is Some.
31    fn when_some<T>(self, option: Option<T>, then: impl FnOnce(Self, T) -> Self) -> Self
32    where
33        Self: Sized,
34    {
35        self.map(|this| {
36            if let Some(value) = option {
37                then(this, value)
38            } else {
39                this
40            }
41        })
42    }
43    /// Conditionally unwrap and modify self with the given closure, if the given option is None.
44    fn when_none<T>(self, option: &Option<T>, then: impl FnOnce(Self) -> Self) -> Self
45    where
46        Self: Sized,
47    {
48        self.map(|this| {
49            if let Some(_) = option {
50                this
51            } else {
52                then(this)
53            }
54        })
55    }
56}
57
58#[cfg(any(test, feature = "test-support"))]
59pub async fn timeout<F, T>(timeout: Duration, f: F) -> Result<T, ()>
60where
61    F: Future<Output = T>,
62{
63    let timer = async {
64        smol::Timer::after(timeout).await;
65        Err(())
66    };
67    let future = async move { Ok(f.await) };
68    timer.race(future).await
69}
70
71#[cfg(any(test, feature = "test-support"))]
72pub struct CwdBacktrace<'a>(pub &'a backtrace::Backtrace);
73
74#[cfg(any(test, feature = "test-support"))]
75impl std::fmt::Debug for CwdBacktrace<'_> {
76    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
77        use backtrace::{BacktraceFmt, BytesOrWideString};
78
79        let cwd = std::env::current_dir().unwrap();
80        let cwd = cwd.parent().unwrap();
81        let mut print_path = |fmt: &mut std::fmt::Formatter<'_>, path: BytesOrWideString<'_>| {
82            std::fmt::Display::fmt(&path, fmt)
83        };
84        let mut fmt = BacktraceFmt::new(f, backtrace::PrintFmt::Full, &mut print_path);
85        for frame in self.0.frames() {
86            let mut formatted_frame = fmt.frame();
87            if frame
88                .symbols()
89                .iter()
90                .any(|s| s.filename().map_or(false, |f| f.starts_with(cwd)))
91            {
92                formatted_frame.backtrace_frame(frame)?;
93            }
94        }
95        fmt.finish()
96    }
97}