Create string type validated

validated_str.rs

use std::{marker::PhantomData, str::FromStr};

use super::error::ValidationError;

pub trait ValidationStrategy {
    fn validate(target: &str) -> Result<String, ValidationError>;
}

pub struct NonEmptyString<V>
where
    V: ValidationStrategy,
{
    pub value: String,
    _marker: PhantomData<fn() -> V>,
}

pub mod rules {
    use super::ValidationStrategy;
    use crate::types::error::ValidationError;

    pub struct LessThanEqualFour;
    impl ValidationStrategy for LessThanEqualFour {
        fn validate(target: &str) -> Result<String, ValidationError> {
            if target.len() <= 4 {
                Ok(target.to_string())
            } else {
                Err(ValidationError::InvalidFormat(format!(
                    "{} must be less than equal 4",
                    &target
                )))
            }
        }
    }

    pub struct LessThanEqualEight;
    impl ValidationStrategy for LessThanEqualEight {
        fn validate(target: &str) -> Result<String, ValidationError> {
            if target.len() <= 8 {
                Ok(target.to_string())
            } else {
                Err(ValidationError::InvalidFormat(format!(
                    "{} must be less than equal 8",
                    &target
                )))
            }
        }
    }
}

impl<T> FromStr for NonEmptyString<T>
where
    T: ValidationStrategy,
{
    type Err = ValidationError;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        if s.is_empty() {
            return Err(ValidationError::NotAllowedEmpty);
        }
        let validated = T::validate(s)?;
        Ok(NonEmptyString {
            value: validated,
            _marker: PhantomData,
        })
    }
}