add-field

name	add-field
description	Add a new field to an existing domain entity, propagating the change across all layers (OpenAPI spec, JPA entity, MapStruct mapper, DB schema). Explicit invocation only — user must type /add-field.

Add Field to Entity

Add a new field to an existing domain entity, propagating the change across all layers.

Instructions

Given:

• Entity: $ENTITY (e.g., Owner, Pet, Vet)
• Field name: $FIELD_NAME
• Field type: $FIELD_TYPE

Follow these steps in order, using TDD — write a failing test first, confirm it fails, then implement.

1. Write a failing test

• Add a test in the appropriate *Test class (e.g., OwnerTest) that verifies the new field is present in the API response or request.
• Run the test and confirm it fails.

2. Update the OpenAPI spec

• Edit petclinic-backend/src/main/resources/openapi.yml
• Add $FIELD_NAME to the relevant DTO schema(s) (request and/or response as appropriate)

3. Regenerate code

cd petclinic-backend && mvn clean install -DskipTests

This regenerates the DTOs in target/generated-sources/.

4. Update the JPA Entity

• Add the field to model/$ENTITY.java
• Use appropriate JPA annotations (@Column, @NotNull, etc.)
• Update Lombok annotations if needed

5. Update the MapStruct Mapper

• Add the field mapping in the relevant mapper (in target/generated-sources/ or handwritten mapper)
• If a custom mapping expression is needed, add it via @Mapping

6. Update DB schema (if needed)

• Add a column to the relevant SQL script in src/main/resources/db/

7. Run the failing test again — it should now pass

cd petclinic-backend && mvn test -Dtest=EntityNameTest

Constraints

• Constructor injection only (no @Autowired in production code)
• Use Lombok where applicable
• Line length ≤ 120 chars
• Follow existing naming conventions in the entity