Module lib::assert_err

Assert macros for Err(_) items.

These macros help compare Err(…) items, such as std::Result::Err or similar.

Assert expression is Err(_):

• assert_err!(a) ≈ a is Err(_)

Compare Err(…) to another Err(…):

• assert_err_eq!(a, b) ≈ (a ⇒ Err(a̅) ⇒ a̅) = (b ⇒ Err(b̅) ⇒ b̅)

• assert_err_ne!(a, b) ≈ (a ⇒ Err(a̅) ⇒ a̅) ≠ (b ⇒ Err(b̅) ⇒ b̅)

Compare Err(…) to an expression:

• assert_err_eq_expr!(a, expr) ≈ (a ⇒ Err(a̅) ⇒ a̅) = b

• assert_err_ne_expr!(a, b) ≈ (a ⇒ Err(a̅) ⇒ a̅) ≠ b

Example

use assertables::*;
let a: Result<(), i8> = Err(1);
assert_err!(a);

Modules

• assert_err
  Assert expression is Err(_).
• assert_err_eq
  Assert two expressions are Err(_) and their values are equal.
• assert_err_eq_expr
  Assert an expression is Err(_) and its value is equal to an expression.
• assert_err_ne
  Assert two expressions are Err(_) and their values are not equal.
• assert_err_ne_expr
  Assert an expression is Err(_) and its value is not equal to an expression.