fed-sx-m1: Step 6a — pipeline:run_stages driver + validate_inbound/outbound + 10 tests

next/kernel/pipeline.erl

@@ -0,0 +1,37 @@
+-module(pipeline).
+-export([run_stages/2,
+         validate_inbound/1, validate_outbound/1,
+         inbound_stages/0, outbound_stages/0]).
+
+%% Validation pipeline per design §14.
+%%
+%% A stage is a 1-arity fun `(Activity) -> ok | {error, Reason}`.
+%% The driver folds the activity through the stage list, halting
+%% on the first error. The pure-functional driver itself takes a
+%% stage list directly so tests can inject ad-hoc stage sequences
+%% without depending on the bundled inbound/outbound lists.
+%%
+%% Inbound pipeline (full set per design §14): envelope, signature,
+%% replay, audience, activity_schema, object_schema, content_validators,
+%% capabilities, trust. Outbound is a subset (no replay, no trust;
+%% auth handled at the HTTP layer).
+%%
+%% This sub-deliverable (6a) wires only the driver and the empty
+%% stage lists. Concrete stages land in 6b-6c.
+
+run_stages(_Activity, []) -> ok;
+run_stages(Activity, [Stage | Rest]) ->
+    Result = Stage(Activity),
+    case Result of
+        ok         -> run_stages(Activity, Rest);
+        {error, _} -> Result
+    end.
+
+validate_inbound(Activity) ->
+    run_stages(Activity, inbound_stages()).
+
+validate_outbound(Activity) ->
+    run_stages(Activity, outbound_stages()).
+
+inbound_stages()  -> [].
+outbound_stages() -> [].