Improve test coverage of emqx_metrics

test/emqx_metrics_SUITE.erl

@@ -26,13 +26,16 @@ t_inc_dec_metrics(_) ->
     {0, 0} = {emqx_metrics:val('bytes/received'), emqx_metrics:val('messages/retained')},
     emqx_metrics:inc('bytes/received'),
     emqx_metrics:inc({counter, 'bytes/received'}, 2),
-    emqx_metrics:inc(counter, 'bytes/received', 2),
+    emqx_metrics:inc(counter, 'bytes/received', 1),
+    emqx_metrics:inc('bytes/received', 1),
     emqx_metrics:inc({gauge, 'messages/retained'}, 2),
     emqx_metrics:inc(gauge, 'messages/retained', 2),
     {5, 4} = {emqx_metrics:val('bytes/received'), emqx_metrics:val('messages/retained')},
     emqx_metrics:dec(gauge, 'messages/retained'),
     emqx_metrics:dec(gauge, 'messages/retained', 1),
     2 = emqx_metrics:val('messages/retained'),
+    emqx_metrics:set('messages/retained', 3),
+    3 = emqx_metrics:val('messages/retained'),
     emqx_metrics:received(#mqtt_packet{header = #mqtt_packet_header{type = ?CONNECT}}),
     {1, 1} = {emqx_metrics:val('packets/received'), emqx_metrics:val('packets/connect')},
     emqx_metrics:sent(#mqtt_packet{header = #mqtt_packet_header{type = ?CONNACK}}),

test/emqx_session_SUITE.erl

@@ -46,7 +46,6 @@ ignore_loop(_Config) ->
 
 t_session_all(_) ->
     emqx_zone:set_env(internal, idle_timeout, 100),
-    application:set_env(emqx, metric_commit_interval, 10),
     ClientId = <<"ClientId">>,
     {ok, ConnPid} = emqx_mock_client:start_link(ClientId),
     {ok, SPid} = emqx_mock_client:open_session(ConnPid, ClientId, internal),