use crate::errors::ValidationError;
use crate::traits::{PrimitiveValue, ValueObject};
pub type PositiveIntInput = i64;
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
#[cfg_attr(feature = "serde", serde(try_from = "i64", into = "i64"))]
pub struct PositiveInt(i64);
impl ValueObject for PositiveInt {
type Input = PositiveIntInput;
type Error = ValidationError;
fn new(value: Self::Input) -> Result<Self, Self::Error> {
if value <= 0 {
return Err(ValidationError::OutOfRange {
type_name: "PositiveInt",
min: "1".into(),
max: i64::MAX.to_string(),
actual: value.to_string(),
});
}
Ok(Self(value))
}
fn into_inner(self) -> Self::Input {
self.0
}
}
impl PrimitiveValue for PositiveInt {
type Primitive = i64;
fn value(&self) -> &i64 {
&self.0
}
}
impl TryFrom<i64> for PositiveInt {
type Error = ValidationError;
fn try_from(v: i64) -> Result<Self, Self::Error> {
Self::new(v)
}
}
#[cfg(feature = "serde")]
impl From<PositiveInt> for i64 {
fn from(v: PositiveInt) -> i64 {
v.0
}
}
impl TryFrom<&str> for PositiveInt {
type Error = ValidationError;
fn try_from(value: &str) -> Result<Self, Self::Error> {
let parsed = value
.trim()
.parse::<i64>()
.map_err(|_| ValidationError::invalid("PositiveInt", value))?;
Self::new(parsed)
}
}
impl std::fmt::Display for PositiveInt {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "{}", self.0)
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn accepts_positive_value() {
let n = PositiveInt::new(1).unwrap();
assert_eq!(*n.value(), 1);
}
#[test]
fn accepts_large_value() {
let n = PositiveInt::new(i64::MAX).unwrap();
assert_eq!(*n.value(), i64::MAX);
}
#[test]
fn rejects_zero() {
assert!(PositiveInt::new(0).is_err());
}
#[test]
fn rejects_negative() {
assert!(PositiveInt::new(-1).is_err());
}
#[test]
fn try_from_parses_valid() {
let v = PositiveInt::try_from("42").unwrap();
assert_eq!(*v.value(), 42);
}
#[test]
fn try_from_rejects_invalid_format() {
assert!(PositiveInt::try_from("abc").is_err());
}
#[test]
fn try_from_rejects_zero() {
assert!(PositiveInt::try_from("0").is_err());
}
#[cfg(feature = "serde")]
#[test]
fn serde_roundtrip() {
let v = PositiveInt::new(42).unwrap();
let json = serde_json::to_string(&v).unwrap();
assert_eq!(json, "42");
let back: PositiveInt = serde_json::from_str(&json).unwrap();
assert_eq!(v, back);
}
#[cfg(feature = "serde")]
#[test]
fn serde_deserialize_validates() {
let result: Result<PositiveInt, _> = serde_json::from_str("0");
assert!(result.is_err());
}
}