1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122

/// Assert a function ok() is less than or equal to another.
///
/// * When true, return `()`.
///
/// * Otherwise, call [`panic!`] with a message and the values of the
///   expressions with their debug representations.
///
/// # Examples
///
/// ```rust
/// # #[macro_use] extern crate assertables;
/// # use std::panic;
/// use std::str::FromStr;
///
/// # fn main() {
/// assert_f_ok_le!(i32::from_str, "1", "2");
/// //-> ()
///
/// # let result = panic::catch_unwind(|| {
/// use std::str::FromStr;
/// assert_f_ok_le!(i32::from_str, "2", "1");
/// //-> panic!("…")
/// // assertion failed: `assert_f_ok_le!(function, left, right)`
/// //    left input: `\"2\"`,
/// //   right input: `\"1\"`,
/// //   left output: `2`,
/// //  right output: `1`
/// # });
/// # let actual = result.unwrap_err().downcast::<String>().unwrap().to_string();
/// # let expect = "assertion failed: `assert_f_ok_le!(function, left, right)`\n   left input: `\"2\"`,\n  right input: `\"1\"`,\n  left output: `2`,\n right output: `1`";
/// # assert_eq!(actual, expect);
/// # }
/// ```
///
/// This macro has a second form where a custom message can be provided.
#[macro_export]
macro_rules! assert_f_ok_le {
    ($function:path, $left:expr, $right:expr $(,)?) => ({
        let left = $function($left);
        let right = $function($right);
        if !left.is_ok() || !right.is_ok() {
            panic!("assertion failed: `assert_f_ok_le!(function, left, right)`\n   left input: `{:?}`,\n  right input: `{:?}`\n  left output is_ok(): `{:?}`,\n right output is_ok(): `{:?}`", $left, $right, left.is_ok(), right.is_ok());
        } else {
            let left = left.unwrap();
            let right = right.unwrap();
            if (left <= right) {
                ()
            } else {
                panic!("assertion failed: `assert_f_ok_le!(function, left, right)`\n   left input: `{:?}`,\n  right input: `{:?}`,\n  left output: `{:?}`,\n right output: `{:?}`", $left, $right, left, right);
            }
        }
    });
    ($function:path, $left:expr, $right:expr, $($arg:tt)+) => ({
        let left = $function($left);
        let right = $function($right);
        if !left.is_ok() || !right.is_ok() {
            panic!("{:?}", $($arg)+)
        } else {
            let left = left.unwrap();
            let right = right.unwrap();
            if (left <= right) {
                ()
            } else {
                panic!("{:?}", $($arg)+)
            }
        }
    });
}

#[cfg(test)]
mod tests {
    use std::str::FromStr;

    #[test]
    fn test_assert_f_ok_le_x_arity_2_lt_success() {
        let a = "1";
        let b = "2";
        let x = assert_f_ok_le!(i32::from_str, a, b);
        assert_eq!(x, ());
    }

    #[test]
    fn test_assert_f_ok_le_x_arity_2_eq_success() {
        let a = "1";
        let b = "1";
        let x = assert_f_ok_le!(i32::from_str, a, b);
        assert_eq!(x, ());
    }

    #[test]
    #[should_panic (expected = "assertion failed: `assert_f_ok_le!(function, left, right)`\n   left input: `\"2\"`,\n  right input: `\"1\"`,\n  left output: `2`,\n right output: `1`")]
    fn test_assert_f_ok_le_x_arity_2_gt_failure() {
        let a = "2";
        let b = "1";
        let _x = assert_f_ok_le!(i32::from_str, a, b);
    }

    #[test]
    fn test_assert_f_ok_le_x_arity_3_lt_success() {
        let a = "1";
        let b = "2";
        let x = assert_f_ok_le!(i32::from_str, a, b, "message");
        assert_eq!(x, ());
    }

    #[test]
    fn test_assert_f_ok_le_x_arity_3_eq_success() {
        let a = "1";
        let b = "1";
        let x = assert_f_ok_le!(i32::from_str, a, b, "message");
        assert_eq!(x, ());
    }

    #[test]
    #[should_panic (expected = "message")]
    fn test_assert_f_ok_le_x_arity_3_failure() {
        let a = "2";
        let b = "1";
        let _x = assert_f_ok_le!(i32::from_str, a, b, "message");
    }

}