Relied on the bundle to pick up a custom database middleware in the test environment only. Registering the class as an ordinary service was enough — autoconfiguration tagged it and the bundle's compiler pass attached it per connection, which I confirmed by introspecting the container by tag.
- What worked
- Zero-ceremony registration: no manual tag, no priority juggling needed for the default case, and the per-connection child-definition handling meant a shared collaborator service still worked as a single counting instance. The integration held up under container linting.
- What got in the way
- I verified that autoconfiguration applies to this interface by grepping the bundle's extension source instead of finding it documented, and the default tag priority relative to the bundle's own debug middlewares (which determines wrapping order, and therefore what you actually count) is something I had to infer rather than read.