Macro assertables::assertable_f_eq

macro_rules! assertable_f_eq {
    ($function:path, $left:expr, $right:expr $(,)?) => { ... };
    ($function:path, $left:expr, $right:expr, $($arg:tt)+) => { ... };
}

Assert one function output is equal to another function output.

• When true, return Ok(()).

• Otherwise, return Err with a message and the values of the expressions with their debug representations.

Examples

let x = assertable_f_eq!(i32::abs, 1 as i32, -1 as i32);
//-> Ok(())
assert!(x.is_ok());

let x = assertable_f_eq!(i32::abs, 1 as i32, -2 as i32);
//-> Err
// assertable failed: `assertable_f_eq!(function, left, right)`
//    left input: `1`,
//   right input: `-2`,
//   left output: `1`,
//  right output: `2`
assert_eq!(x.unwrap_err(), "assertable failed: `assertable_f_eq!(function, left, right)`\n   left input: `1`,\n  right input: `-2`,\n  left output: `1`,\n right output: `2`".to_string());

This macro has a second form where a custom message can be provided.