testutils/
bool_ext.rs

1//! Extension trait for types that can be converted into a bool.
2pub trait BoolExt {
3  /// Converts the bool value into a `Result<(), E>`.
4  ///
5  /// If the value is `true`, it returns `Ok(())`. If the value is `false`, it
6  /// returns `Err(err())`.
7  ///
8  /// # Examples
9  ///
10  /// ## Simple
11  ///
12  /// ```
13  /// use testutils::bool_ext::BoolExt;
14  ///
15  /// let value = true;
16  /// let res: Result<(), &str> = value.then_ok_or_else(|| "error");
17  /// assert_eq!(res, Ok(()));
18  ///
19  /// let value = false;
20  /// assert_eq!(value.then_ok_or_else(|| "error"), Err("error"));
21  /// ```
22  ///
23  /// ## A more complex example
24  ///
25  /// ```ignore
26  /// use testutils::tap::Pipe;
27  /// use testutils::get_pkg_name;
28  /// use testutils::testutils::bool_ext::BoolExt;
29  /// use std::io;
30  ///
31  /// let err = || "Failed to run `cargo rustdoc` command".pipe(io::Error::other);
32  ///
33  /// get_pkg_name!()
34  ///  .pipe(build_rsdoc)? // ExitStatus
35  ///  .success() // bool
36  ///  .then_ok_or_else(err) // io::Result<()>
37  /// ```
38  fn then_ok_or_else<E>(self, err_fn: impl FnOnce() -> E) -> Result<(), E>
39  where
40    Self: Into<bool>,
41  {
42    if self.into() { Ok(()) } else { Err(err_fn()) }
43  }
44
45  fn then_ok_or<E>(self, err: E) -> Result<(), E>
46  where
47    Self: Into<bool>,
48  {
49    if self.into() { Ok(()) } else { Err(err) }
50  }
51}
52
53impl BoolExt for bool {}
54
55#[cfg(test)]
56mod tests {
57  use tap::TapOptional;
58
59  use super::*;
60
61  #[ignore]
62  #[test]
63  fn test_tap_opt() {
64    let opt = Some(42);
65    opt.tap_some(|&x| assert_eq!(x, 42));
66    opt.map(|x| assert_eq!(x, 42));
67  }
68
69  #[ignore]
70  #[test]
71  fn test_bool_ok_or_else() {
72    let value = true;
73    let res: Result<(), &str> = value.then_ok_or_else(|| "error");
74    assert_eq!(res, Ok(()));
75
76    let value = false;
77    assert_eq!(value.then_ok_or_else(|| "error"), Err("error"));
78  }
79
80  #[cfg(feature = "std")]
81  #[ignore]
82  #[test]
83  fn test_bool_ok_or_std_io_error() {
84    // use std::io;
85  }
86}
testutils/bool_ext.rs

testutils/
bool_ext.rs
