StateSet Core

Pure domain models and business logic for commerce operations. This crate has no I/O dependencies - just data structures and validation.

Overview

stateset-core provides the foundational types for the StateSet iCommerce platform:

• Domain Models: Strongly-typed structs for all commerce entities
• Repository Traits: Abstract interfaces for data access
• Error Types: Comprehensive error handling with categorization
• Validation: Composable validation builders and traits
• Events: Domain event types for event-driven architectures

Core Domains

Error Handling

All operations return Result<T, CommerceError>. Errors can be categorized:

use stateset_core::CommerceError;

fn handle_error(err: &CommerceError) {
    if err.is_not_found() {
        // Handle not found errors (404)
    } else if err.is_validation() {
        // Handle validation errors (400)
    } else if err.is_conflict() {
        // Handle conflict errors (409)
    } else if err.is_database() {
        // Handle database errors (500)
    } else if err.is_retryable() {
        // Retry the operation
    }
}

Validation

Use ValidationBuilder for composable validations:

use stateset_core::{ValidationBuilder, Result};

fn validate_order(email: &str, quantity: i32) -> Result<()> {
    ValidationBuilder::new()
        .email("email", email)
        .positive_i32("quantity", quantity)
        .build()
}

Or implement the Validate trait for domain models:

use stateset_core::{Validate, ValidationBuilder, Result};

struct OrderInput {
    email: String,
    quantity: i32,
}

impl Validate for OrderInput {
    fn validate(&self) -> Result<()> {
        ValidationBuilder::new()
            .email("email", &self.email)
            .positive_i32("quantity", self.quantity)
            .build()
    }
}

// Use with method chaining
// let input = OrderInput { ... }.validated()?;

Example

use stateset_core::prelude::*;
use rust_decimal_macros::dec;

// Create an order input
let order = CreateOrder {
    customer_id: uuid::Uuid::new_v4(),
    items: vec![CreateOrderItem {
        sku: "SKU-001".to_string(),
        name: "Widget".to_string(),
        quantity: 2,
        unit_price: dec!(29.99),
        ..Default::default()
    }],
    ..Default::default()
};

Feature Flags

• embeddings - Enable vector search via embedding services
• metrics - Enable Prometheus metrics support