domain-entity
Domain Entity
Goal
Define a domain entity as a domain object with a unique identity that persists over time, even as its attributes change.
A domain entity encapsulates business behavior, business rules, and invariants related to its own data. It acts as a core building block in the domain or business layer for concepts such as a customer, order, subscription, account, or shipment.
Treat a domain entity as identity-driven code. The key question is whether the object represents a specific domain concept that remains the same thing throughout its lifecycle while its state evolves.
What Counts as a Domain Entity
Classify code as a domain entity when it does one or more of these things:
- represents a specific domain concept through a stable identity
- carries an identifier that distinguishes one instance from another across time
- preserves continuity as state changes throughout a lifecycle
- exposes behaviors that apply domain rules to its own data
- enforces invariants that must remain true for that specific domain concept
More from code-sherpas/agent-skills
neverthrow-return-types
Require `neverthrow`-based return types in TypeScript and JavaScript code whenever the surrounding technology allows it. Use when creating, refactoring, reviewing, or extending standalone functions, exported module functions, class methods, object methods, service methods, repository methods, and similar APIs that should expose explicit success and failure result types in their signatures. Prefer `Result<T, E>` for synchronous code and `ResultAsync<T, E>` for asynchronous code. Only skip a `neverthrow` return type when a framework, library, runtime interface, or externally imposed contract is incompatible and requires a different return shape.
19neverthrow-wrap-exceptions
Capture exceptions and promise failures with `neverthrow` instead of hand-written `try/catch` in TypeScript and JavaScript code. Use when wrapping synchronous functions that may throw, promise-returning functions that may throw before returning, existing `PromiseLike` values that may reject, or third-party APIs such as parsers, database clients, HTTP clients, file-system helpers, serializers, and SDK calls. Prefer `Result.fromThrowable` for synchronous throwers, `ResultAsync.fromThrowable` for promise-returning functions that may throw or reject, and `ResultAsync.fromPromise` when you already have a `PromiseLike` value in hand. Only keep `try/catch` when the language construct, cleanup requirement, or framework boundary truly requires it.
14atomic-design
Create or update web UI components with a strict reuse-first workflow. Use when building, refactoring, restyling, or extending frontend or template components while minimizing raw DOM or HTML by reusing or generalizing existing components first.
11write-persistence-representations
Create or update persistence-layer data representations in any stack, including ORM entities, schema definitions, table mappings, document models, collection definitions, and similar database-facing code. Use when agents needs to add or change persisted fields, identifiers, relationships, indexes, timestamps, auditing fields, or storage mappings in frameworks, libraries, or ORMs such as Prisma, TypeORM, Sequelize, Drizzle, Mongoose, Hibernate/JPA, Doctrine, Ecto, Active Record, or equivalent persistence technologies.
8business-logic
Identify, interpret, review, or write business logic in code. Use when an agent needs to decide whether code expresses business rules, business algorithms, or business workflows, or when it must implement, preserve, or refactor code that creates, stores, or transforms data according to real business policies.
8immutable-domain-entities
Require the immutable design pattern for domain entities. Use when an agent needs to create, modify, review, or interpret domain entities and should preserve identity while expressing state changes through new immutable instances. Domain entities must be modeled as immutable classes, not as plain type aliases or interfaces paired with standalone functions.
8