fed-sx-m1: Step 8c-post-publish-srv — gen_server-wrapped nx_kernel (start_link + publish/query/log_tip) + 11 tests

next/kernel/nx_kernel.erl

@@ -1,8 +1,12 @@
 -module(nx_kernel).
+-behaviour(gen_server).
 -export([new/3, publish/2,
          actor_id/1, log_state/1, log_tip/1,
          key_spec/1, actor_state/1, projections/1,
          next_published/1, with_projections/2]).
+-export([start_link/3, publish/1, query/0, log_tip/0,
+         with_projections/1, stop/0]).
+-export([init/1, handle_call/3, handle_cast/2, handle_info/2]).
 
 %% Kernel orchestrator — the long-lived runtime state held by the
 %% running fed-sx instance. The HTTP layer (Step 8c-post-publish
@@ -80,3 +84,56 @@ field(_, []) -> nil.
 set(K, V, []) -> [{K, V}];
 set(K, V, [{K, _} | Rest]) -> [{K, V} | Rest];
 set(K, V, [P | Rest]) -> [P | set(K, V, Rest)].
+
+%% ── gen_server wrapper ──────────────────────────────────────────
+%%
+%% Mirrors the registry / projection gen_server patterns from
+%% Steps 5b and 7b. Same port quirks: raw Pid return, no `?MODULE`
+%% macro, spawned processes don't persist across separate
+%% erlang-eval-ast calls — tests inline start_link with operations.
+
+start_link(ActorId, KeySpec, ActorStateProplist) ->
+    Pid = gen_server:start_link(nx_kernel,
+            [ActorId, KeySpec, ActorStateProplist]),
+    erlang:register(nx_kernel, Pid),
+    Pid.
+
+stop() ->
+    R = gen_server:call(nx_kernel, '$gen_stop'),
+    erlang:unregister(nx_kernel),
+    R.
+
+publish(Request) ->
+    gen_server:call(nx_kernel, {publish, Request}).
+
+query() ->
+    gen_server:call(nx_kernel, get_state).
+
+log_tip() ->
+    gen_server:call(nx_kernel, get_log_tip).
+
+with_projections(Names) ->
+    gen_server:call(nx_kernel, {set_projections, Names}).
+
+%% gen_server callbacks
+
+init([ActorId, KeySpec, AS]) ->
+    {ok, new(ActorId, KeySpec, AS)}.
+
+handle_call({publish, Request}, _From, State) ->
+    case publish(Request, State) of
+        {ok, Result, NewState} ->
+            {reply, {ok, Result}, NewState};
+        {error, Reason, SameState} ->
+            {reply, {error, Reason}, SameState}
+    end;
+handle_call(get_state, _From, State) ->
+    {reply, State, State};
+handle_call(get_log_tip, _From, State) ->
+    {reply, log_tip(State), State};
+handle_call({set_projections, Names}, _From, State) ->
+    {reply, ok, with_projections(Names, State)}.
+
+handle_cast(_, S) -> {noreply, S}.
+
+handle_info(_, S) -> {noreply, S}.