mcl-testkit

A test harness for mcl-* services. It runs a service's real mesh path (mcl_om:macula_client/0, mcl_om:realm/0, macula:publish/subscribe) over an in-memory macula mesh, with no station, no QUIC and no certificate.

It composes macula_testkit's loopback pools into the mcl_om identity. with_mesh/1 stands up a two-pool cluster and stubs the identity (with meck), so the service resolves the SERVICE pool and a test realm. The harness keeps the second, TEST pool: it publishes facts "from another node" and asserts on what the service publishes back.

echo_round_trip_test() ->
    mcl_testkit:with_mesh(fun(Mesh) ->
        {ok, _} = mcl_testkit:boot_service(my_service),
        ok = mcl_testkit:subscribe(Mesh, <<"out">>),
        ok = mcl_testkit:publish(Mesh, <<"in">>, #{n => 1}),
        #{echoed := _} = mcl_testkit:await(<<"out">>, fun(P) -> maps:is_key(echoed, P) end)
    end).

Install

As a test dependency:

{profiles, [{test, [{deps, [{mcl_testkit, "~> 0.1"}]}]}]}.

API

Function	What it does
`with_mesh(Fun)`, `with_mesh(#{realm => R}, Fun)`	Runs `Fun(Mesh)` on a fresh in-memory mesh, then removes the stub and stops the cluster. The realm defaults to 32 zero bytes.
`boot_service(Mod)`, `boot_service(Mod, #{apps => [...]})`	Starts `mcl_om`, boots `Mod` through `mcl_om:boot/1`, then starts the listed sibling applications.
`publish(Mesh, Topic, Fact)`	Publishes from the TEST pool, as another node would.
`subscribe(Mesh, Topic)`	Subscribes the calling process through the TEST pool.
`await(Topic, Match)`, `await(Topic, Match, Ms)`	Waits for a fact on `Topic` that `Match` accepts. Raises `{await_timeout, Topic}` after 2 s by default. Events for other topics stay in the mailbox.
`service_pool/1`, `test_pool/1`, `realm/1`	Read the mesh.

Pub/sub only, like macula_testkit: RPC and advertise are not simulated.

Licence

Apache-2.0. See LICENSE.