| 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
