Fix empty state field in /api/deprecated-features/used endpoint

The /api/deprecated-features/used endpoint was returning an empty
state field in the JSON response. This was a regression introduced
in #14229, which added the state field to show whether deprecated
features are permitted or denied.

The issue was that rabbit_depr_ff_extra:cli_info0/1 always tried to
extract the state field with a default empty string, even when
rabbit_deprecated_features:list(used) doesn't include a state
field (unlike list(all) which does).

This commit fixes the issue by only including the state field when
it exists in the feature properties, using maps:find/2 and maps:merge/2
to conditionally add it.

The fix ensures that:
- /api/deprecated-features returns state field with valid values
- /api/deprecated-features/used omits the state field entirely

Tests are updated to verify this behavior.

GitHub issue: #14340

Author: bas0N

deps/rabbit/src/rabbit_depr_ff_extra.erl

@@ -58,14 +58,17 @@ cli_info0(DeprecatedFeature) ->
 
               App = maps:get(provided_by, FeatureProps),
               DeprecationPhase = maps:get(deprecation_phase, FeatureProps, ""),
-              State = maps:get(state, FeatureProps, ""),
               Desc = maps:get(desc, FeatureProps, ""),
               DocUrl = maps:get(doc_url, FeatureProps, ""),
-              Info = #{name => FeatureName,
-                       desc => unicode:characters_to_binary(Desc),
-                       deprecation_phase => DeprecationPhase,
-                       state => State,
-                       doc_url => unicode:characters_to_binary(DocUrl),
-                       provided_by => App},
+              BaseInfo = #{name => FeatureName,
+                          desc => unicode:characters_to_binary(Desc),
+                          deprecation_phase => DeprecationPhase,
+                          doc_url => unicode:characters_to_binary(DocUrl),
+                          provided_by => App},
+              Info = maps:merge(BaseInfo,
+                               case maps:find(state, FeatureProps) of
+                                   {ok, State} -> #{state => State};
+                                   error        -> #{}
+                               end),
               [Info | Acc]
       end, [], lists:sort(maps:keys(DeprecatedFeature))).

deps/rabbitmq_management/test/rabbit_mgmt_http_SUITE.erl

@@ -4218,7 +4218,9 @@ list_deprecated_features_test(Config) ->
     ?assertEqual(<<"permitted_by_default">>, maps:get(deprecation_phase, Feature)),
     ?assertEqual(atom_to_binary(?MODULE), maps:get(provided_by, Feature)),
     ?assertEqual(list_to_binary(Desc), maps:get(desc, Feature)),
-    ?assertEqual(list_to_binary(DocUrl), maps:get(doc_url, Feature)).
+    ?assertEqual(list_to_binary(DocUrl), maps:get(doc_url, Feature)),
+    ?assert(maps:is_key(state, Feature)),
+    ?assert(lists:member(maps:get(state, Feature), [<<"permitted">>, <<"denied">>])).
 
 list_used_deprecated_features_test(Config) ->
     Desc = "This is a deprecated feature in use",
@@ -4239,7 +4241,8 @@ list_used_deprecated_features_test(Config) ->
     ?assertEqual(<<"removed">>, maps:get(deprecation_phase, Feature)),
     ?assertEqual(atom_to_binary(?MODULE), maps:get(provided_by, Feature)),
     ?assertEqual(list_to_binary(Desc), maps:get(desc, Feature)),
-    ?assertEqual(list_to_binary(DocUrl), maps:get(doc_url, Feature)).
+    ?assertEqual(list_to_binary(DocUrl), maps:get(doc_url, Feature)),
+    ?assertNot(maps:is_key(state, Feature)).
 
 cluster_and_node_tags_test(Config) ->
     Overview = http_get(Config, "/overview"),