Skip to content

docs: add incompatibleWith authoring rules (fixes #119) #190

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
ulises-jeremias merged 1 commit into from
Aug 24, 2026
Merged

docs: add incompatibleWith authoring rules (fixes #119) #190

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
24 changes: 16 additions & 8 deletions docs/AUTHORING.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -397,22 +397,30 @@ Full reference: [create-python-app `docs/PYPROJECT_MERGE.md`](https://github.com
- An extension has a `type` string **or array** of strings.
- An extension is compatible when `template.type` appears in `[extension.type].flat()`.

### `incompatibleWith`
### `incompatibleWith` — when and how

Declare mutually exclusive extensions in `templates.json`. CPA validates selected combinations at scaffold time.
Use `incompatibleWith` when two extensions would write the same file for the same `type` — e.g. `Dockerfile`, `compose.yml`, `.env.example`, or `pyproject.toml` overlay. Example: `celery-docker` vs `flower-docker` both target `celery-worker` and ship a Compose stack for the same worker (similarly, two FastAPI middleware extensions that both patch `app/core/providers.py`).

- **Symmetric (required):** if `A` lists `B`, then `B` must list `A`. Validated by [`scripts/ci/validate-registry.py`](../scripts/ci/validate-registry.py) (symmetry + existence).
- **Same `type` only:** both extensions must share the same `type` (e.g. `celery-worker`). Cross-type is rare and needs justification.
- **Slugs, not names:** reference the `slug` field.

```json
{
"name": "Example A",
"slug": "example-a",
"incompatibleWith": ["example-b"],
"...": "..."
"slug": "flower-docker",
"incompatibleWith": ["celery-docker"]
},
{
"slug": "celery-docker",
"incompatibleWith": ["flower-docker"]
}
```

When two extensions logically conflict (two middleware choices, two container runtimes), add `incompatibleWith` on **both** entries. Use this for logical conflicts; use semver or dependency constraints for softer peer restrictions.
- **Validation:** `python scripts/ci/validate-registry.py` fails on unknown or asymmetric slugs.
- **Testing:** L2 fails if both extensions are selected together (combination rejected at scaffold time).
- **Schema:** [`templates.schema.json`](../templates.schema.json) → `extensions[].incompatibleWith`.

Schema: `templates.schema.json` → `extensions[].incompatibleWith`.
See also the [path-collision rules](#incompatiblewith-path-collisions) above.

## Generation order

Expand Down