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

use crate::MaximumErrorParams;

/// Maximum of the number validation.
///
/// See <https://json-schema.org/understanding-json-schema/reference/numeric.html#range>
pub trait ValidateMaximum<T>
where
    T: PartialOrd + PartialEq,
{
    fn validate_maximum(&self, maximum: T) -> Result<(), MaximumErrorParams>;
}

macro_rules! impl_validate_numeric_maximum {
    ($ty:ty) => {
        impl ValidateMaximum<$ty> for $ty {
            fn validate_maximum(&self, maximum: $ty) -> Result<(), MaximumErrorParams> {
                if *self <= maximum {
                    Ok(())
                } else {
                    Err(MaximumErrorParams::new(maximum))
                }
            }
        }
    };
}

impl_validate_numeric_maximum!(i8);
impl_validate_numeric_maximum!(i16);
impl_validate_numeric_maximum!(i32);
impl_validate_numeric_maximum!(i64);
impl_validate_numeric_maximum!(i128);
impl_validate_numeric_maximum!(isize);
impl_validate_numeric_maximum!(u8);
impl_validate_numeric_maximum!(u16);
impl_validate_numeric_maximum!(u32);
impl_validate_numeric_maximum!(u64);
impl_validate_numeric_maximum!(u128);
impl_validate_numeric_maximum!(usize);
impl_validate_numeric_maximum!(f32);
impl_validate_numeric_maximum!(f64);

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_validate_numeric_maximum_is_true() {
        // Unspecified generic type:
        assert!(ValidateMaximum::validate_maximum(&10, 11).is_ok());
        assert!(ValidateMaximum::validate_maximum(&10, 10).is_ok());
    }

    #[test]
    fn test_validate_numeric_maximum_is_false() {
        assert!(ValidateMaximum::validate_maximum(&5, 4).is_err());
    }

    #[test]
    fn test_validate_numeric_maximum_specified_type() {
        assert!(ValidateMaximum::validate_maximum(&0.2, 0.5).is_ok());
        assert!(ValidateMaximum::validate_maximum(&0, 5u8).is_ok());
        assert!(ValidateMaximum::validate_maximum(&0, 4u16).is_ok());
        assert!(ValidateMaximum::validate_maximum(&0, 6u32).is_ok());
    }
}