result_extensions/
lib.rs

1//! # Result Extensions
2//!
3//! A simple library that functionally creates Result<T, E> values from arbitrary types.
4//!
5//! Usage:
6//! ```
7//! mod some_mod {
8//! use result_extensions::ResultExtensions;
9//!     fn is_greater_than_ten(input: i64) -> Result<bool, String> {
10//!         match input {
11//!             i64::MIN..=0 => {
12//!                 "this function does not accept values less than or equal to zero for some reason"
13//!                     .to_string()
14//!                     .to_err()
15//!             }
16//!             1..=9 => false.to_ok(),
17//!             _ => true.to_ok(),
18//!         }
19//!     }
20//! }
21
22/// Allows any Sized type to be functionally moved into a Result<T, E>.
23pub trait ResultExtensions
24where
25    Self: Sized,
26{
27    /// Converts the caller into an Ok (left-hand-side) Result.
28    fn to_ok<E>(self) -> Result<Self, E> {
29        Ok(self)
30    }
31
32    /// Converts the caller into an Err (right-hand-side) Result.
33    fn to_err<T>(self) -> Result<T, Self> {
34        Err(self)
35    }
36}
37impl<T> ResultExtensions for T {}
38
39#[cfg(test)]
40mod tests {
41    use crate::ResultExtensions;
42
43    #[test]
44    fn test_to_ok() {
45        let result = get_ok("ok");
46        if let Ok(ok_text) = result {
47            assert_eq!("ok", ok_text, "unexpected Ok text",);
48        } else {
49            panic!("expected result to be an Ok variant, but got: {:?}", result);
50        }
51    }
52
53    #[test]
54    fn test_to_err() {
55        let result = get_err("error");
56        if let Err(err_text) = result {
57            assert_eq!("error", err_text, "unexpected Err text",);
58        } else {
59            panic!(
60                "expected result to be an Err variant, but got: {:?}",
61                result
62            );
63        }
64    }
65
66    fn get_ok<S: Into<String>>(ok_value: S) -> Result<String, String> {
67        ok_value.into().to_ok()
68    }
69
70    fn get_err<S: Into<String>>(err_value: S) -> Result<String, String> {
71        err_value.into().to_err()
72    }
73}
result_extensions/lib.rs

result_extensions/
lib.rs
