chore(emqx_modules): improve emqx_topic_metrics coverage

apps/emqx_modules/src/emqx_topic_metrics.erl

@@ -21,6 +21,7 @@
 -include_lib("emqx/include/emqx.hrl").
 -include_lib("emqx/include/logger.hrl").
 -include_lib("emqx/include/emqx_mqtt.hrl").
+-include_lib("snabbkaffe/include/snabbkaffe.hrl").
 
 -export([
     on_message_publish/1,
@@ -212,6 +213,7 @@ init([Opts]) ->
                     error("max topic metrics quota exceeded")
             end
         end,
+    ?tp(debug, emqx_topic_metrics_started, #{}),
     {ok, #state{speeds = lists:foldl(Fun, #{}, Opts)}, hibernate}.
 
 handle_call({register, Topic}, _From, State = #state{speeds = Speeds}) ->
@@ -262,7 +264,7 @@ handle_call({get_rates, Topic, Metric}, _From, State = #state{speeds = Speeds})
     end.
 
 handle_cast(Msg, State) ->
-    ?SLOG(error, #{msg => "unexpected_cast", cast => Msg}),
+    ?tp(error, emqx_topic_metrics_unexpected_cast, #{cast => Msg}),
     {noreply, State}.
 
 handle_info(ticking, State = #state{speeds = Speeds}) ->
@@ -278,7 +280,7 @@ handle_info(ticking, State = #state{speeds = Speeds}) ->
     erlang:send_after(timer:seconds(?TICKING_INTERVAL), self(), ticking),
     {noreply, State#state{speeds = NSpeeds}};
 handle_info(Info, State) ->
-    ?SLOG(error, #{msg => "unexpected_info", info => Info}),
+    ?tp(error, emqx_topic_metrics_unexpected_info, #{info => Info}),
     {noreply, State}.
 
 terminate(_Reason, _State) ->

apps/emqx_modules/test/emqx_topic_metrics_SUITE.erl

@@ -19,14 +19,10 @@
 -compile(export_all).
 -compile(nowarn_export_all).
 
--define(TOPIC, <<
-    ""
-    "\n"
-    "topic_metrics: []"
-    ""
->>).
+-define(TOPIC, #{<<"topic_metrics">> => []}).
 
 -include_lib("eunit/include/eunit.hrl").
+-include_lib("snabbkaffe/include/snabbkaffe.hrl").
 
 all() -> emqx_common_test_helpers:all(?MODULE).
 
@@ -39,8 +35,17 @@ init_per_suite(Config) ->
 end_per_suite(_Config) ->
     emqx_common_test_helpers:stop_apps([emqx_modules]).
 
-t_nonexistent_topic_metrics(_) ->
+init_per_testcase(_Case, Config) ->
     emqx_topic_metrics:enable(),
+    emqx_topic_metrics:deregister_all(),
+    Config.
+
+end_per_testcase(_Case, _Config) ->
+    emqx_topic_metrics:deregister_all(),
+    emqx_config:put([topic_metrics], []),
+    emqx_topic_metrics:disable().
+
+t_nonexistent_topic_metrics(_) ->
     ?assertEqual({error, topic_not_found}, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.in')),
     ?assertEqual({error, topic_not_found}, emqx_topic_metrics:inc(<<"a/b/c">>, 'messages.in')),
     ?assertEqual({error, topic_not_found}, emqx_topic_metrics:rate(<<"a/b/c">>, 'messages.in')),
@@ -56,12 +61,9 @@ t_nonexistent_topic_metrics(_) ->
     %%     emqx_topic_metrics:rates(<<"a/b/c">>, 'invalid.metrics')
     %% ),
 
-    emqx_topic_metrics:deregister(<<"a/b/c">>),
-    emqx_topic_metrics:disable().
+    ok = emqx_topic_metrics:deregister(<<"a/b/c">>).
 
 t_topic_metrics(_) ->
-    emqx_topic_metrics:enable(),
-
     ?assertEqual(false, emqx_topic_metrics:is_registered(<<"a/b/c">>)),
     ?assertEqual([], emqx_topic_metrics:all_registered_topics()),
     emqx_topic_metrics:register(<<"a/b/c">>),
@@ -78,11 +80,9 @@ t_topic_metrics(_) ->
     %%         #{long => 0, medium => 0, short => 0}
     %% ),
 
-    emqx_topic_metrics:deregister(<<"a/b/c">>),
-    emqx_topic_metrics:disable().
+    ok = emqx_topic_metrics:deregister(<<"a/b/c">>).
 
 t_hook(_) ->
-    emqx_topic_metrics:enable(),
     emqx_topic_metrics:register(<<"a/b/c">>),
 
     ?assertEqual(0, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.in')),
@@ -97,19 +97,85 @@ t_hook(_) ->
         {username, "myuser"}
     ]),
     {ok, _} = emqtt:connect(C),
-    emqtt:publish(C, <<"a/b/c">>, <<"Hello world">>, 0),
+    emqtt:publish(C, <<"a/b/c">>, <<"Hello world">>, [{qos, 0}]),
+    emqtt:publish(C, <<"a/b/c">>, <<"Hello world">>, [{qos, 1}]),
+    emqtt:publish(C, <<"a/b/c">>, <<"Hello world">>, [{qos, 2}]),
     ct:sleep(100),
-    ?assertEqual(1, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.in')),
+    ?assertEqual(3, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.in')),
     ?assertEqual(1, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.qos0.in')),
-    ?assertEqual(1, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.dropped')),
+    ?assertEqual(1, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.qos1.in')),
+    ?assertEqual(1, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.qos2.in')),
+    ?assertEqual(3, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.dropped')),
 
-    emqtt:subscribe(C, <<"a/b/c">>),
-    emqtt:publish(C, <<"a/b/c">>, <<"Hello world">>, 0),
+    emqtt:subscribe(C, <<"a/b/c">>, [{qos, 2}]),
+    ct:sleep(100),
+    emqtt:publish(C, <<"a/b/c">>, <<"Hello world">>, [{qos, 0}]),
+    emqtt:publish(C, <<"a/b/c">>, <<"Hello world">>, [{qos, 1}]),
+    emqtt:publish(C, <<"a/b/c">>, <<"Hello world">>, [{qos, 2}]),
     ct:sleep(100),
-    ?assertEqual(2, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.in')),
+    ?assertEqual(6, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.in')),
     ?assertEqual(2, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.qos0.in')),
-    ?assertEqual(1, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.out')),
+    ?assertEqual(2, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.qos1.in')),
+    ?assertEqual(2, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.qos2.in')),
+    ?assertEqual(3, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.out')),
     ?assertEqual(1, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.qos0.out')),
-    ?assertEqual(1, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.dropped')),
-    emqx_topic_metrics:deregister(<<"a/b/c">>),
-    emqx_topic_metrics:disable().
+    ?assertEqual(1, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.qos1.out')),
+    ?assertEqual(1, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.qos2.out')),
+    ?assertEqual(3, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.dropped')),
+    ok = emqx_topic_metrics:deregister(<<"a/b/c">>).
+
+t_topic_server_restart(_) ->
+    emqx_config:put([topic_metrics], [#{topic => <<"a/b/c">>}]),
+    ?check_trace(
+        begin
+            ?wait_async_action(
+                erlang:exit(whereis(emqx_topic_metrics), kill),
+                #{?snk_kind := emqx_topic_metrics_started},
+                500
+            )
+        end,
+        fun(Trace) ->
+            ?assertMatch(
+                [_ | _],
+                ?of_kind(emqx_topic_metrics_started, Trace)
+            )
+        end
+    ),
+
+    ?assertEqual(
+        [<<"a/b/c">>],
+        emqx_topic_metrics:all_registered_topics()
+    ).
+
+t_unknown_messages(_) ->
+    OldPid = whereis(emqx_topic_metrics),
+    ?check_trace(
+        begin
+            ?wait_async_action(
+                OldPid ! unknown,
+                #{?snk_kind := emqx_topic_metrics_unexpected_info},
+                500
+            ),
+            ?wait_async_action(
+                gen_server:cast(OldPid, unknown),
+                #{?snk_kind := emqx_topic_metrics_unexpected_cast},
+                500
+            )
+        end,
+        fun(Trace) ->
+            ?assertMatch(
+                [_ | _],
+                ?of_kind(emqx_topic_metrics_unexpected_info, Trace)
+            ),
+            ?assertMatch(
+                [_ | _],
+                ?of_kind(emqx_topic_metrics_unexpected_cast, Trace)
+            )
+        end
+    ),
+
+    %% emqx_topic_metrics did not crash from unexpected calls
+    ?assertEqual(
+        OldPid,
+        whereis(emqx_topic_metrics)
+    ).