Module assert_fn_err 

Assert for comparing functions that return errors.

These macros help compare functions that return results that are errors, such as ::std::Result::Err or similar.

The macros use these capabilities:

• implements .is_err() -> bool

• implements .unwrap_err() -> comparable

Compare a function Err() with another function Err():

• assert_fn_err_eq!(a_function, b_function) ≈ a_function().unwrap_err() = b_function().unwrap_err()
• assert_fn_err_ne!(a_function, b_function) ≈ a_function().unwrap_err() ≠ b_function().unwrap_err()
• assert_fn_err_ge!(a_function, b_function) ≈ a_function().unwrap_err() ≥ b_function().unwrap_err()
• assert_fn_err_gt!(a_function, b_function) ≈ a_function().unwrap_err() > b_function().unwrap_err()
• assert_fn_err_le!(a_function, b_function) ≈ a_function().unwrap_err() ≤ b_function().unwrap_err()
• assert_fn_err_lt!(a_function, b_function) ≈ a_function().unwrap_err() < b_function().unwrap_err()

Compare a function Err() with an expression:

• assert_fn_err_eq_x!(function, expr) ≈ function().unwrap_err() = expr
• assert_fn_err_ne_x!(function, expr) ≈ function().unwrap_err() ≠ expr
• assert_fn_err_ge_x!(function, expr) ≈ function().unwrap_err() ≥ expr
• assert_fn_err_gt_x!(function, expr) ≈ function().unwrap_err() > expr
• assert_fn_err_le_x!(function, expr) ≈ function().unwrap_err() ≤ expr
• assert_fn_err_lt_x!(function, expr) ≈ function().unwrap_err() < expr

Example

use assertables::*;
fn f(i: i8) -> Result<String, String> {
    match i {
        0..=9 => Ok(format!("{}", i)),
        _ => Err(format!("{:?} is out of range", i)),
    }
}

let a: i8 = 10;
let b: i8 = 10;
assert_fn_err_eq!(f, a, f, b);

Modules

assert_fn_err_eq

Assert a function Err(…) is equal to another.

assert_fn_err_eq_x

Assert a function Err(…) is equal to an expression.

assert_fn_err_ge

Assert a function Err(…) is greater than or equal to another.

assert_fn_err_ge_x

Assert a function Err(…) is greater than or equal to an expression.

assert_fn_err_gt

Assert a function Err(…) is greater than another.

assert_fn_err_gt_x

Assert a function Err(…) is greater than an expression.

assert_fn_err_le

Assert a function Err(…) is less than or equal to another.

assert_fn_err_le_x

Assert a function Err(…) is less than or equal to an expression.

assert_fn_err_lt

Assert a function Err(…) is less than another.

assert_fn_err_lt_x

Assert a function Err(…) is less than an expression.

assert_fn_err_ne

Assert a function Err(…) is not equal to another.

assert_fn_err_ne_x

Assert a function Err(…) is not equal to an expression.