macula-testkit

In-memory test support for macula consumers. Run the real macula pub/sub stack in-process, with no QUIC, no certificates, and no station.

It provides:

1. A drop-in loopback pool (mem_macula): a gen_server that speaks the macula_client pool protocol, so macula:publish(Pool, ...) / macula:subscribe(Pool, ...) work unchanged against an in-memory mesh. A publish on one pool reaches subscribers on any pool in the cluster.
2. A harness + assertions (planned): stand up an N-node in-memory mesh and assert delivery, so any macula consumer can test its mesh behaviour fast.

It mirrors the command-side pattern: evoq -> mem-evoq -> evoq-testkit becomes macula -> macula-testkit (mem_macula) -> consumers.

The pool is the real seam, not the transport plugin. The SDK pub/sub path is hardcoded to QUIC below the pool (macula_peering_conn), so an in-memory macula_net_transport would not make macula:publish/subscribe work; the pool gen_server protocol is where the in-memory swap lives. See the proposal for the full finding.

{ok, #{pools := [A, B]} = Cluster} = mem_macula:cluster(2),
{ok, _Ref} = macula:subscribe(B, Realm, Topic, self()),
ok = macula:publish(A, Realm, Topic, Fact),
%% self() receives {macula_event, _, Topic, Fact, _}
ok = mem_macula:stop(Cluster).

Status

Proposal stage. Design lives in proposals/PROPOSAL_MACULA_TESTKIT.md. Companion: hecate-services/hecate-testkit composes this into the hecate service-boot path.

License

Apache-2.0. See LICENSE.