1/// A number of cents.
 2#[derive(
 3    Debug,
 4    PartialEq,
 5    Eq,
 6    PartialOrd,
 7    Ord,
 8    Hash,
 9    Clone,
10    Copy,
11    derive_more::Add,
12    derive_more::AddAssign,
13)]
14pub struct Cents(pub u32);
15
16impl Cents {
17    pub const ZERO: Self = Self(0);
18
19    pub const fn new(cents: u32) -> Self {
20        Self(cents)
21    }
22
23    pub const fn from_dollars(dollars: u32) -> Self {
24        Self(dollars * 100)
25    }
26
27    pub fn saturating_sub(self, other: Cents) -> Self {
28        Self(self.0.saturating_sub(other.0))
29    }
30}
31
32#[cfg(test)]
33mod tests {
34    use pretty_assertions::assert_eq;
35
36    use super::*;
37
38    #[test]
39    fn test_cents_new() {
40        assert_eq!(Cents::new(50), Cents(50));
41    }
42
43    #[test]
44    fn test_cents_from_dollars() {
45        assert_eq!(Cents::from_dollars(1), Cents(100));
46        assert_eq!(Cents::from_dollars(5), Cents(500));
47    }
48
49    #[test]
50    fn test_cents_zero() {
51        assert_eq!(Cents::ZERO, Cents(0));
52    }
53
54    #[test]
55    fn test_cents_add() {
56        assert_eq!(Cents(50) + Cents(30), Cents(80));
57    }
58
59    #[test]
60    fn test_cents_add_assign() {
61        let mut cents = Cents(50);
62        cents += Cents(30);
63        assert_eq!(cents, Cents(80));
64    }
65
66    #[test]
67    fn test_cents_saturating_sub() {
68        assert_eq!(Cents(50).saturating_sub(Cents(30)), Cents(20));
69        assert_eq!(Cents(30).saturating_sub(Cents(50)), Cents(0));
70    }
71
72    #[test]
73    fn test_cents_ordering() {
74        assert!(Cents(50) > Cents(30));
75        assert!(Cents(30) < Cents(50));
76        assert_eq!(Cents(50), Cents(50));
77    }
78}