fed-sx-m1: Step 8c-post-publish-http — POST /activity wires through nx_kernel:publish + 10 tests

next/kernel/http_server.erl

@@ -7,7 +7,9 @@
          projections_list_path/0, projections_prefix/0,
          projections_list_response/0, projection_response/1,
          activity_path/0, unauthorized_response/0,
-         post_activity_response/0]).
+         post_activity_response/0,
+         validation_failed_response/0,
+         cid_response/1]).
 
 %% HTTP request router per design §16.1.
 %%
@@ -199,11 +201,46 @@ post_activity_response() ->
 handle_post_activity(Req, Cfg) ->
     case check_bearer(Req, Cfg) of
         ok ->
-            post_activity_response();
+            publish_if_kernel(Req);
         {error, _} ->
             unauthorized_response()
     end.
 
+%% publish_if_kernel/1 — if the nx_kernel gen_server is registered,
+%% delegate the publish there and translate the result. Otherwise
+%% keep the stub response so the auth-only tests stay green without
+%% having to spin up a kernel process.
+publish_if_kernel(Req) ->
+    case erlang:whereis(nx_kernel) of
+        undefined ->
+            post_activity_response();
+        _Pid ->
+            Body = field(body, Req),
+            Request = [{type, create}, {object, Body}],
+            case nx_kernel:publish(Request) of
+                {ok, Result} ->
+                    case envelope:get_field(cid, Result) of
+                        {ok, Cid} -> cid_response(Cid);
+                        _         -> post_activity_response()
+                    end;
+                {error, _} ->
+                    validation_failed_response()
+            end
+    end.
+
+%% 200 OK with body "cid: <cid>\n" (5 prefix bytes + cid + newline)
+cid_response(Cid) ->
+    %% "cid: " — 99 105 100 58 32
+    Pre = <<99,105,100,58,32>>,
+    Body = <<Pre/binary, Cid/binary, 10>>,
+    ok_response(Body).
+
+%% 422 Unprocessable Entity. Body "validation failed\n" — 18 bytes.
+validation_failed_response() ->
+    [{status, 422}, {headers, []},
+     {body, <<118,97,108,105,100,97,116,105,111,110,32,
+              102,97,105,108,101,100,10>>}].
+
 check_bearer(Req, Cfg) ->
     case bearer_token(Req) of
         {ok, Got} ->