ts-ddd-simplify

name	ts-ddd-simplify
description	Review and simplify TypeScript DDD code — remove unnecessary complexity, eliminate duplication, reduce premature abstraction. Trigger when the user says "simplify this", "too much boilerplate", "over-engineered", "clean this up", "refactor this", or when code has grown too abstract or introduces patterns before they prove value.

Simplify — TypeScript DDD

Three similar lines is better than a premature abstraction. Abstract only when a pattern has appeared in at least three real cases.

What to look for

Domain over-engineering

• VO wrapping a single string with no validation or behavior — remove it (keep if it enforces format like Email, Money)
• Aggregate that only delegates to a domain service for every operation — collapse the service into the aggregate
• Deeply nested event hierarchy (DomainEvent → OrderEvent → OrderCancelledEvent) — flatten unless used for polymorphic handling

Application over-engineering

• Handler with one line return this.repo.findById(id) — skip the use case, call the repo from the query handler directly
• Command DTO with fields identical to the domain constructor params — collapse into one
• Interface with a single implementation that is never mocked in tests — inject the concrete class; add the interface when a second impl is needed

Infrastructure over-engineering

• Mapper that copies fields one-for-one with no type conversion — consider if domain and ORM models are actually the same thing at this stage
• Repository wrapping ORM with one-liner methods and no mapping or error handling — the layer adds no value yet

Premature patterns

Pattern	Worth it when	Premature when
CQRS with separate read models	Queries are complex joins or aggregations	Simple CRUD reads
Event sourcing	Full audit trail or temporal queries required	Standard transactional state
Outbox pattern	Distributed at-least-once delivery needed	Single service, no message broker
Sagas / Process Managers	Multi-step multi-service long-running workflows	Single aggregate transitions

What NOT to simplify

• Invariant-enforcing VOs even if they look like "just a string wrapper"
• Repository interface when it enables test doubles
• Domain events even if only one subscriber currently listens
• Mapper even if trivial — it protects the domain from ORM schema changes

Output format

Numbered list. Each finding: [REMOVE] / [COLLAPSE] / [DEFER] + file path + why it's safe to remove + what to do instead.