test(schema registry): add test asserting the behavior of empty message roundtrip

Relates to https://emqx.atlassian.net/browse/EMQX-10866

apps/emqx_schema_registry/test/emqx_schema_registry_SUITE.erl

@@ -49,12 +49,22 @@ sparkplug_tests() ->
     ].
 
 init_per_suite(Config) ->
-    emqx_config:save_schema_mod_and_names(emqx_schema_registry_schema),
+    Apps = emqx_cth_suite:start(
-    emqx_mgmt_api_test_util:init_suite(?APPS),
+        [
-    Config.
+            emqx,
+            emqx_conf,
+            emqx_rule_engine,
+            emqx_schema_registry,
+            emqx_management,
+            emqx_mgmt_api_test_util:emqx_dashboard()
+        ],
+        #{work_dir => emqx_cth_suite:work_dir(Config)}
+    ),
+    [{apps, Apps} | Config].
 
-end_per_suite(_Config) ->
+end_per_suite(Config) ->
-    emqx_mgmt_api_test_util:end_suite(lists:reverse(?APPS)),
+    Apps = ?config(apps, Config),
+    emqx_cth_suite:stop(Apps),
     ok.
 
 init_per_group(avro, Config) ->

apps/emqx_schema_registry/test/emqx_schema_registry_http_api_SUITE.erl

@@ -7,6 +7,7 @@
 -compile(export_all).
 
 -import(emqx_mgmt_api_test_util, [uri/1]).
+-import(emqx_common_test_helpers, [on_exit/1]).
 
 -include_lib("eunit/include/eunit.hrl").
 -include_lib("common_test/include/ct.hrl").
@@ -14,34 +15,51 @@
 
 -include("emqx_schema_registry.hrl").
 
--define(APPS, [emqx_conf, emqx_schema_registry]).
-
 %%------------------------------------------------------------------------------
 %% CT boilerplate
 %%------------------------------------------------------------------------------
 
 all() ->
+    OnlyOnceTCs = only_once_testcases(),
     [
         {group, avro},
         {group, protobuf},
         {group, json}
+        | OnlyOnceTCs
     ].
 
 groups() ->
+    OnlyOnceTCs = only_once_testcases(),
     AllTCs = emqx_common_test_helpers:all(?MODULE),
+    PerTypeTCs = AllTCs -- OnlyOnceTCs,
     [
-        {avro, AllTCs},
+        {avro, PerTypeTCs},
-        {protobuf, AllTCs},
+        {protobuf, PerTypeTCs},
-        {json, AllTCs}
+        {json, PerTypeTCs}
+    ].
+
+only_once_testcases() ->
+    [
+        t_empty_sparkplug
     ].
 
 init_per_suite(Config) ->
-    emqx_config:save_schema_mod_and_names(emqx_schema_registry_schema),
+    Apps = emqx_cth_suite:start(
-    emqx_mgmt_api_test_util:init_suite(?APPS),
+        [
-    Config.
+            emqx,
+            emqx_conf,
+            emqx_rule_engine,
+            emqx_schema_registry,
+            emqx_management,
+            emqx_mgmt_api_test_util:emqx_dashboard()
+        ],
+        #{work_dir => emqx_cth_suite:work_dir(Config)}
+    ),
+    [{apps, Apps} | Config].
 
-end_per_suite(_Config) ->
+end_per_suite(Config) ->
-    emqx_mgmt_api_test_util:end_suite(lists:reverse(?APPS)),
+    Apps = ?config(apps, Config),
+    emqx_cth_suite:stop(Apps),
     ok.
 
 init_per_group(avro, Config) ->
@@ -112,6 +130,7 @@ init_per_testcase(_TestCase, Config) ->
 end_per_testcase(_TestCase, _Config) ->
     clear_schemas(),
     ok = snabbkaffe:stop(),
+    emqx_common_test_helpers:call_janitor(),
     ok.
 
 %%------------------------------------------------------------------------------
@@ -119,21 +138,20 @@ end_per_testcase(_TestCase, _Config) ->
 %%------------------------------------------------------------------------------
 
 request(get) ->
-    do_request(get, _Parts = [], _Body = []);
+    do_request(get, uri(["schema_registry"]), _Body = []);
 request({get, Name}) ->
-    do_request(get, _Parts = [Name], _Body = []);
+    do_request(get, uri(["schema_registry", Name]), _Body = []);
 request({delete, Name}) ->
-    do_request(delete, _Parts = [Name], _Body = []);
+    do_request(delete, uri(["schema_registry", Name]), _Body = []);
 request({put, Name, Params}) ->
-    do_request(put, _Parts = [Name], Params);
+    do_request(put, uri(["schema_registry", Name]), Params);
 request({post, Params}) ->
-    do_request(post, _Parts = [], Params).
+    do_request(post, uri(["schema_registry"]), Params).
 
-do_request(Method, PathParts, Body) ->
+do_request(Method, Path, Body) ->
     Header = emqx_common_test_http:default_auth_header(),
-    URI = uri(["schema_registry" | PathParts]),
     Opts = #{compatible_mode => true, httpc_req_opts => [{body_format, binary}]},
-    Res0 = emqx_mgmt_api_test_util:request_api(Method, URI, [], Header, Body, Opts),
+    Res0 = emqx_mgmt_api_test_util:request_api(Method, Path, [], Header, Body, Opts),
     case Res0 of
         {ok, Code, <<>>} ->
             {ok, Code, <<>>};
@@ -163,6 +181,28 @@ clear_schemas() ->
         emqx_schema_registry:list_schemas()
     ).
 
+dryrun_rule(SQL, Context) ->
+    Params = #{
+        context => Context,
+        sql => SQL
+    },
+    Path = emqx_mgmt_api_test_util:api_path(["rule_test"]),
+    Res = do_request(post, Path, Params),
+    ct:pal("dryrun rule result:\n  ~p", [Res]),
+    case Res of
+        {ok, {{_, 201, _}, _, #{<<"id">> := RuleId}}} ->
+            on_exit(fun() -> ok = emqx_rule_engine:delete_rule(RuleId) end),
+            simplify_result(Res);
+        _ ->
+            simplify_result(Res)
+    end.
+
+simplify_result(Res) ->
+    case Res of
+        {ok, Status, Body} ->
+            {Status, Body}
+    end.
+
 %%------------------------------------------------------------------------------
 %% Testcases
 %%------------------------------------------------------------------------------
@@ -329,3 +369,33 @@ t_crud(Config) ->
     ),
 
     ok.
+
+t_empty_sparkplug(_Config) ->
+    ?check_trace(
+        begin
+            SQL = <<
+                "select sparkplug_decode(sparkplug_encode(json_decode(payload))) as decoded"
+                " from \"t\" "
+            >>,
+            Context = #{
+                <<"clientid">> => <<"c_emqx">>,
+                <<"event_type">> => <<"message_publish">>,
+                <<"payload">> => <<"{}">>,
+                <<"qos">> => 1,
+                <<"topic">> => <<"t">>,
+                <<"username">> => <<"u_emqx">>
+            },
+            %% N.B.: It's not an error for a `metrics' field to "appear out of nowhere"
+            %% after a roundtrip.  Since Sparkplug B schema uses proto 2, and the `metrics'
+            %% field is `repeated', this field has no presence tracking, hence it's
+            %% impossible to distinguish between an absent field and a field with its
+            %% default value (an empty array, in this case).
+            %% https://protobuf.dev/programming-guides/field_presence/#presence-in-proto2-apis
+            ?assertMatch(
+                {200, #{<<"decoded">> := #{<<"metrics">> := []}}}, dryrun_rule(SQL, Context)
+            ),
+            ok
+        end,
+        []
+    ),
+    ok.