assertables

Macro assert_fn_ok_lt_expr

source 
macro_rules! assert_fn_ok_lt_expr {
    ($a_function:path, $a_param:expr, $b_expr:expr $(,)?) => { ... };
    ($a_function:path, $a_param:expr, $b_expr:expr, $($message:tt)+) => { ... };
    ($a_function:path, $b_expr:expr $(,)?) => { ... };
    ($a_function:path, $b_expr:expr, $($message:tt)+) => { ... };
}
Expand description

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

Pseudocode:
(function1(param1) ⇒ Ok(a) ⇒ a) < expr

  • If true, return ().

  • Otherwise, call panic! with a message and the values of the expressions with their debug representations.

§Examples

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 = 1;
let b = String::from("2");
assert_fn_ok_lt_expr!(f, a, b);

// This will panic
let a: i8 = 2;
let b = String::from("1");
assert_fn_ok_lt_expr!(f, a, b);
// assertion failed: `assert_fn_ok_lt_expr!(a_function, a_param, b_expr)`
// https://docs.rs/assertables/8.18.0/assertables/macro.assert_fn_ok_lt_expr.html
//  a_function label: `f`,
//     a_param label: `a`,
//     a_param debug: `2`,
//      b_expr label: `b`,
//      b_expr debug: `\"1\"`,
//                 a: `\"2\"`,
//                 b: `\"1\"`

§Module macros