feophantlib/constants/
nullable.rs

1//! Defining if something is null or not so I'm not using a bool everywhere
2
3use std::fmt;
4
5#[derive(Clone, Copy, Debug, PartialEq)]
6pub enum Nullable {
7    Null,
8    NotNull,
9}
10
11impl From<bool> for Nullable {
12    fn from(b: bool) -> Self {
13        if b {
14            Nullable::Null
15        } else {
16            Nullable::NotNull
17        }
18    }
19}
20
21impl From<u8> for Nullable {
22    fn from(u: u8) -> Self {
23        if u == 0x0 {
24            Nullable::Null
25        } else {
26            Nullable::NotNull
27        }
28    }
29}
30
31impl fmt::Display for Nullable {
32    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
33        match self {
34            Nullable::NotNull => write!(f, "NotNull"),
35            Nullable::Null => write!(f, "Null"),
36        }
37    }
38}
39
40#[cfg(test)]
41mod tests {
42    use super::*;
43
44    #[test]
45    fn test_nullable_display() -> Result<(), Box<dyn std::error::Error>> {
46        assert_eq!(Nullable::NotNull.to_string(), "NotNull".to_string());
47        assert_eq!(Nullable::Null.to_string(), "Null".to_string());
48        Ok(())
49    }
50
51    #[test]
52    fn test_nullable_from() -> Result<(), Box<dyn std::error::Error>> {
53        assert_eq!(Nullable::from(false), Nullable::NotNull);
54        assert_eq!(Nullable::from(true), Nullable::Null);
55
56        assert_eq!(Nullable::from(0), Nullable::Null);
57        for u in 1..u8::MAX {
58            assert_eq!(Nullable::from(u), Nullable::NotNull);
59        }
60
61        Ok(())
62    }
63}
feophantlib/constants/nullable.rs

feophantlib/constants/
nullable.rs
