fix(bpapi): Add exceptions for experimental features

apps/emqx/test/emqx_bpapi_static_checks.erl

@@ -81,6 +81,12 @@
     "emqx_mgmt_api:do_query/2, emqx_mgmt_api:collect_total_from_tail_nodes/2"
 ).
 
+%% Only the APIs for the features that haven't reached General
+%% Availability can be added here:
+-define(EXPERIMENTAL_APIS, [
+    {emqx_ds, 4}
+]).
+
 -define(XREF, myxref).
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@@ -132,7 +138,19 @@ check_compat(_, _) ->
 check_api_immutability(#{release := Rel1, api := APIs1}, #{release := Rel2, api := APIs2}) ->
     %% TODO: Handle API deprecation
     _ = maps:map(
-        fun(Key = {API, Version}, Val) ->
+        fun(Key, Val) ->
+                case lists:member(Key, ?EXPERIMENTAL_APIS) of
+                    true ->
+                        ok;
+                    false ->
+                        do_check_api_immutability(Rel1, Rel2, APIs2, Key, Val)
+                end
+        end,
+        APIs1
+    ),
+    ok.
+
+do_check_api_immutability(Rel1, Rel2, APIs2, Key = {API, Version}, Val) ->
     case maps:get(Key, APIs2, undefined) of
         Val ->
             ok;
@@ -148,17 +166,18 @@ check_api_immutability(#{release := Rel1, api := APIs1}, #{release := Rel2, api
                         [API, Version, Rel2, Rel1]
                     )
             end;
-                _Val ->
+        OldVal ->
             setnok(),
             logger:error(
                 "API ~p v~p was changed between ~p and ~p. Backplane API should be immutable.",
                 [API, Version, Rel1, Rel2]
-                    )
-            end
-        end,
-        APIs1
             ),
-    ok.
+            D21 = maps:get(calls, Val) -- maps:get(calls, OldVal),
+            D12 = maps:get(calls, OldVal) -- maps:get(calls, Val),
+            logger:error("Added calls:~n  ~p", [D21]),
+            logger:error("Removed calls:~n  ~p", [D12])
+    end.
+
 
 filter_calls(Calls) ->
     F = fun({{Mf, _, _}, {Mt, _, _}}) ->