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() -> boolean

• implements .unwrap_err() -> comparable

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

• assert_fn_err_eq2!(a_function, b_function) ≈ a_function().unwrap_err() = b_function().unwrap_err()

• assert_fn_err_ne2!(a_function, b_function) ≈ a_function().unwrap_err() ≠ b_function().unwrap_err()

• assert_fn_err_ge2!(a_function, b_function) ≈ a_function().unwrap_err() ≥ b_function().unwrap_err()

• assert_fn_err_gt2!(a_function, b_function) ≈ a_function().unwrap_err() > b_function().unwrap_err()

• assert_fn_err_le2!(a_function, b_function) ≈ a_function().unwrap_err() ≤ b_function().unwrap_err()

• assert_fn_err_lt2!(a_function, b_function) ≈ a_function().unwrap_err() < b_function().unwrap_err()

Compare a function Err() with an expression:

• assert_fn_err_eq2!(function, expr) ≈ function().unwrap_err() = expr

• assert_fn_err_ne2!(function, expr) ≈ function().unwrap_err() ≠ expr

• assert_fn_err_ge2!(function, expr) ≈ function().unwrap_err() ≥ expr

• assert_fn_err_gt2!(function, expr) ≈ function().unwrap_err() > expr

• assert_fn_err_le2!(function, expr) ≈ function().unwrap_err() ≤ expr

• assert_fn_err_lt2!(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_eq2!(f, a, f, b);

Modules

• assert_fn_err_eq
  Assert a function Err(…) is equal to an expression.
• assert_fn_err_eq2
  Assert a function Err(…) is equal to another.
• assert_fn_err_ge
  Assert a function Err(…) is greater than or equal to an expression.
• assert_fn_err_ge2
  Assert a function Err(…) is greater than or equal to another.
• assert_fn_err_gt
  Assert a function Err(…) is greater than an expression.
• assert_fn_err_gt2
  Assert a function Err(…) is greater than another.
• assert_fn_err_le
  Assert a function Err(…) is less than or equal to an expression.
• assert_fn_err_le2
  Assert a function Err(…) is less than or equal to another.
• assert_fn_err_lt
  Assert a function Err(…) is less than an expression.
• assert_fn_err_lt2
  Assert a function Err(…) is less than another.
• assert_fn_err_ne
  Assert a function Err(…) is not equal to an expression.
• assert_fn_err_ne2
  Assert a function Err(…) is not equal to another.