hexser 0.4.7

Zero-boilerplate hexagonal architecture with graph-based introspection
Documentation 
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//! HexValueItem trait for domain objects defined by their values.
//!
//! Value objects are immutable objects that are defined entirely by their
//! attribute values. Two value objects with the same attribute values are
//! considered identical. Value objects have no identity and should be immutable.
//! They are used to model descriptive aspects of the domain with no conceptual identity.
//!
//! Revision History
//! - 2025-10-09T09:43:00Z @AI: Rename ValueObject to HexValueItem for consistency.
//! - 2025-10-01T00:00:00Z @AI: Initial ValueObject trait definition with validation.

/// Trait for domain value objects.
///
/// Value objects are defined by their values, not by identity. They should be
/// immutable and two value objects with the same values are considered equal.
///
/// # Example
///
/// ```rust
/// use hexser::domain::HexValueItem;
/// use hexser::HexResult;
///
/// #[derive(Clone, PartialEq, Eq)]
/// struct Email(String);
///
/// impl HexValueItem for Email {
///     fn validate(&self) -> HexResult<()> {
///         if self.0.contains('@') {
///             Ok(())
///         } else {
///             Err(hexser::Hexserror::validation("Invalid email format"))
///         }
///     }
/// }
/// ```
pub trait HexValueItem {
  /// Validate the value object's invariants.
  ///
  /// Returns `Ok(())` if the value object is valid, or an error describing
  /// what validation rules were violated.
  fn validate(&self) -> crate::result::hex_result::HexResult<()>;
}

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

  #[derive(Clone)]
  struct TestEmail(String);

  impl HexValueItem for TestEmail {
    fn validate(&self) -> crate::result::hex_result::HexResult<()> {
      if self.0.contains('@') {
        Result::Ok(())
      } else {
        Result::Err(crate::error::hex_error::Hexserror::validation_field(
          "Email must contain @",
          "email",
        ))
      }
    }
  }

  #[test]
  fn test_value_object_validation_success() {
    let email = TestEmail(String::from("test@example.com"));
    assert!(email.validate().is_ok());
  }

  #[test]
  fn test_value_object_validation_failure() {
    let email = TestEmail(String::from("invalid"));
    assert!(email.validate().is_err());
  }
}