fed-sx-m1: Step 8c-actors-doc — match_prefix + GET /actors/{id} route + 13 tests

next/kernel/http_server.erl

@@ -1,7 +1,8 @@
 -module(http_server).
 -export([route/1, ok_response/1, not_found_response/0,
          welcome_body/0, capabilities_body/0,
-         capabilities_path/0]).
+         capabilities_path/0,
+         match_prefix/2, actors_prefix/0, actor_doc_response/1]).
 
 %% HTTP request router per design §16.1.
 %%
@@ -34,6 +35,17 @@ dispatch(<<71, 69, 84>>,
          <<47,46,119,101,108,108,45,107,110,111,119,110,
            47,115,120,45,99,97,112,97,98,105,108,105,116,105,101,115>>) ->
     ok_response(capabilities_body());
+%% GET /actors/{id}
+dispatch(<<71, 69, 84>>, Path) ->
+    case match_prefix(actors_prefix(), Path) of
+        {ok, Id} ->
+            case byte_size(Id) of
+                0 -> not_found_response();
+                _ -> actor_doc_response(Id)
+            end;
+        nomatch ->
+            not_found_response()
+    end;
 dispatch(_, _) ->
     not_found_response().
 
@@ -73,3 +85,30 @@ not_found_response() ->
 field(K, [{K, V} | _]) -> V;
 field(K, [_ | Rest]) -> field(K, Rest);
 field(_, []) -> nil.
+
+%% ── Dynamic-segment routing ─────────────────────────────────────
+%%
+%% match_prefix(Prefix, Path) — if Path starts with the entire
+%% Prefix binary, return {ok, Rest} where Rest is the remaining
+%% bytes; else return nomatch. Pure byte-level pattern match,
+%% no regex / no parsing. Path-segment splitting comes in later
+%% sub-deliverables (8c-art, 8c-proj) where it's needed.
+
+match_prefix(<<>>, Rest) -> {ok, Rest};
+match_prefix(<<B, PRest/binary>>, <<B, PathRest/binary>>) ->
+    match_prefix(PRest, PathRest);
+match_prefix(_, _) -> nomatch.
+
+%% "/actors/" — 8 bytes: 47 97 99 116 111 114 115 47
+actors_prefix() ->
+    <<47,97,99,116,111,114,115,47>>.
+
+%% Actor doc stub. Real implementation (Step 8c continuation) will
+%% fetch the actor-state projection entry and serialise it; v1
+%% returns the id as the body so route resolution can be exercised
+%% end-to-end without the projection wiring.
+actor_doc_response(Id) ->
+    %% "actor: " — 7 bytes
+    Pre = <<97,99,116,111,114,58,32>>,
+    Body = <<Pre/binary, Id/binary, 10>>,
+    ok_response(Body).