rails-service-object_skill

Overview

This skill generates Rails service objects that follow the single-responsibility principle and include comprehensive RSpec specs. It scaffolds a consistent service interface (single #call method) and a reusable Result object so services return a predictable success/failure contract. Use it to extract business logic from controllers, jobs, or background workers while keeping code testable and maintainable.

How this skill works

The skill creates a namespaced service class with an initializer that accepts injected dependencies and a single public #call method that returns a Result object. It also generates focused RSpec examples (red/green workflow) that drive implementation, plus helper files like a shared Result class and optional base ApplicationService. Error handling, transactions, and dependency mocking are illustrated in the generated code and tests.

When to use it

• Extract complex business logic from controllers or models
• Implement operations that coordinate multiple models or external APIs
• Create interactors or POROs with clear input/output contracts
• Encapsulate side effects (email, payment, inventory) for testability
• Prefer models for simple CRUD; skip service for trivial single-model validation

Best practices

• Name services VerbNounService and place under app/services/[namespace]
• Expose a single public #call and always return a Result object
• Inject dependencies via the constructor to allow easy mocking
• Write the service spec first (RED), implement, then iterate on error cases
• Keep services focused; avoid accumulating unrelated responsibilities

Example use cases

• Orders::CreateService: validate inventory, create order, charge payment, send confirmation
• Users::RegisterService: create user, send welcome email, schedule background tasks
• Payments::ChargeService: call external gateway, update records, handle retries
• Jobs invoking services to run idempotent business flows and log failures
• Shared operations used by multiple controllers or rake tasks