chore: fix elvis warnings

apps/emqx/src/emqx_limiter/src/emqx_limiter_schema.erl

@@ -94,7 +94,8 @@ fields(client_bucket) ->
     , {initial, sc(initial(), #{default => "0"})}
       %% low_water_mark add for emqx_channel and emqx_session
       %% both modules consume first and then check
-      %% so we need to use this value to prevent excessive consumption (e.g, consumption from an empty bucket)
+      %% so we need to use this value to prevent excessive consumption
+      %% (e.g, consumption from an empty bucket)
     , {low_water_mark, sc(initial(),
                           #{desc => "if the remaining tokens are lower than this value,
 the check/consume will succeed, but it will be forced to hang for a short period of time",

apps/emqx/src/emqx_limiter/src/emqx_limiter_server.erl

@@ -89,6 +89,8 @@
 -export_type([index/0]).
 -import(emqx_limiter_decimal, [add/2, sub/2, mul/2,  put_to_counter/3]).
 
+-elvis([{elvis_style, no_if_expression, disable}]).
+
 %%--------------------------------------------------------------------
 %% API
 %%--------------------------------------------------------------------
@@ -337,8 +339,9 @@ longitudinal(#{id := Id,
 
     case lists:min([ShouldAlloc, Flow, Capacity]) of
         Avaiable when Avaiable > 0 ->
-            %% XXX if capacity is infinity, and flow always > 0, the value in counter
+            %% XXX if capacity is infinity, and flow always > 0, the value in
-            %% will be overflow at some point in the future, do we need to deal with this situation???
+            %% counter will be overflow at some point in the future, do we need
+            %% to deal with this situation???
             {Inc, Node2} = emqx_limiter_correction:add(Avaiable, Node),
             counters:add(Counter, Index, Inc),
 

apps/emqx/test/emqx_channel_SUITE.erl

@@ -923,7 +923,12 @@ t_ws_cookie_init(_) ->
                  conn_mod => emqx_ws_connection,
                  ws_cookie => WsCookie
                 },
-    Channel = emqx_channel:init(ConnInfo, #{zone => default, limiter => limiter_cfg(), listener => {tcp, default}}),
+    Channel = emqx_channel:init(
+                ConnInfo,
+                #{zone => default,
+                  limiter => limiter_cfg(),
+                  listener => {tcp, default}
+                 }),
     ?assertMatch(#{ws_cookie := WsCookie}, emqx_channel:info(clientinfo, Channel)).
 
 %%--------------------------------------------------------------------
@@ -948,7 +953,12 @@ channel(InitFields) ->
     maps:fold(fun(Field, Value, Channel) ->
                       emqx_channel:set_field(Field, Value, Channel)
               end,
-              emqx_channel:init(ConnInfo, #{zone => default, limiter => limiter_cfg(), listener => {tcp, default}}),
+              emqx_channel:init(
+                ConnInfo,
+                #{zone => default,
+                  limiter => limiter_cfg(),
+                  listener => {tcp, default}
+                 }),
               maps:merge(#{clientinfo => clientinfo(),
                            session    => session(),
                            conn_state => connected

apps/emqx_exhook/src/emqx_exhook_api.erl

@@ -77,7 +77,8 @@ schema("/exhooks/:name") ->
                   description => <<"Delete the server">>,
                   parameters => params_server_name_in_path(),
                   responses => #{204 => <<>>,
-                                 500 => error_codes([?BAD_RPC], <<"Bad RPC">>)                                }
+                                 500 => error_codes([?BAD_RPC], <<"Bad RPC">>)
+                                }
                  }
      };
 
@@ -176,7 +177,8 @@ action_with_name(put, #{bindings := #{name := Name}, body := Body}) ->
                    }};
         {ok, {error, Reason}} ->
             {400, #{code => <<"BAD_REQUEST">>,
-                    message => unicode:characters_to_binary(io_lib:format("Error Reason:~p~n", [Reason]))
+                    message => unicode:characters_to_binary(
+                                 io_lib:format("Error Reason:~p~n", [Reason]))
                    }};
         {ok, _} ->
             {200};

apps/emqx_retainer/src/emqx_retainer.erl

@@ -461,11 +461,9 @@ check_timer(Timer, _, _) ->
 
 -spec get_backend_module() -> backend().
 get_backend_module() ->
-    #{type := Backend} = emqx:get_config([retainer, config]),
+    ModName = case emqx:get_config([retainer, config]) of
-    ModName = if Backend =:= built_in_database ->
+                  #{type := built_in_database} -> mnesia;
-                      mnesia;
+                  #{type := Backend} -> Backend
-                 true ->
-                      Backend
               end,
     erlang:list_to_existing_atom(io_lib:format("~ts_~ts", [?APP, ModName])).
 

apps/emqx_retainer/src/emqx_retainer_mnesia.erl

@@ -95,7 +95,11 @@ store_retained(_, Msg =#message{topic = Topic}) ->
             end,
             case mria:transaction(?RETAINER_SHARD, Fun) of
                 {atomic, ok} ->  ok;
-                {aborted, Reason} -> ?SLOG(error, #{msg => "failed_to_retain_message", topic => Topic, reason => Reason})
+                {aborted, Reason} ->
+                    ?SLOG(error, #{ msg => "failed_to_retain_message"
+                                  , topic => Topic
+                                  , reason => Reason
+                                  })
             end
     end.
 

apps/emqx_retainer/test/emqx_retainer_SUITE.erl

@@ -90,7 +90,10 @@ t_store_and_clean(_) ->
     {ok, C1} = emqtt:start_link([{clean_start, true}, {proto_ver, v5}]),
     {ok, _} = emqtt:connect(C1),
 
-    emqtt:publish(C1, <<"retained">>, <<"this is a retained message">>, [{qos, 0}, {retain, true}]),
+    emqtt:publish(
+      C1, <<"retained">>,
+      <<"this is a retained message">>,
+      [{qos, 0}, {retain, true}]),
     timer:sleep(100),
     {ok, #{}, [0]} = emqtt:subscribe(C1, <<"retained">>, [{qos, 0}, {rh, 0}]),
     ?assertEqual(1, length(receive_messages(1))),
@@ -118,7 +121,10 @@ t_retain_handling(_) ->
     ?assertEqual(0, length(receive_messages(1))),
     {ok, #{}, [0]} = emqtt:unsubscribe(C1, <<"retained/#">>),
 
-    emqtt:publish(C1, <<"retained">>, <<"this is a retained message">>, [{qos, 0}, {retain, true}]),
+    emqtt:publish(
+      C1, <<"retained">>,
+      <<"this is a retained message">>,
+      [{qos, 0}, {retain, true}]),
 
     {ok, #{}, [0]} = emqtt:subscribe(C1, <<"retained">>, [{qos, 0}, {rh, 0}]),
     ?assertEqual(1, length(receive_messages(1))),
@@ -148,9 +154,18 @@ t_retain_handling(_) ->
 t_wildcard_subscription(_) ->
     {ok, C1} = emqtt:start_link([{clean_start, true}, {proto_ver, v5}]),
     {ok, _} = emqtt:connect(C1),
-    emqtt:publish(C1, <<"retained/0">>, <<"this is a retained message 0">>, [{qos, 0}, {retain, true}]),
+    emqtt:publish(
-    emqtt:publish(C1, <<"retained/1">>, <<"this is a retained message 1">>, [{qos, 0}, {retain, true}]),
+      C1, <<"retained/0">>,
-    emqtt:publish(C1, <<"retained/a/b/c">>, <<"this is a retained message 2">>, [{qos, 0}, {retain, true}]),
+      <<"this is a retained message 0">>,
+      [{qos, 0}, {retain, true}]),
+    emqtt:publish(
+      C1, <<"retained/1">>,
+      <<"this is a retained message 1">>,
+      [{qos, 0}, {retain, true}]),
+    emqtt:publish(
+      C1, <<"retained/a/b/c">>,
+      <<"this is a retained message 2">>,
+      [{qos, 0}, {retain, true}]),
 
     {ok, #{}, [0]} = emqtt:subscribe(C1,  <<"retained/+">>, 0),
     {ok, #{}, [0]} = emqtt:subscribe(C1,  <<"retained/+/b/#">>, 0),
@@ -165,11 +180,26 @@ t_message_expiry(_) ->
     {ok, C1} = emqtt:start_link([{clean_start, true}, {proto_ver, v5}]),
     {ok, _} = emqtt:connect(C1),
 
-    emqtt:publish(C1, <<"retained/0">>, #{'Message-Expiry-Interval' => 0}, <<"don't expire">>, [{qos, 0}, {retain, true}]),
+    emqtt:publish(
-    emqtt:publish(C1, <<"retained/1">>, #{'Message-Expiry-Interval' => 2}, <<"expire">>, [{qos, 0}, {retain, true}]),
+      C1, <<"retained/0">>, #{'Message-Expiry-Interval' => 0},
-    emqtt:publish(C1, <<"retained/2">>, #{'Message-Expiry-Interval' => 5}, <<"don't expire">>, [{qos, 0}, {retain, true}]),
+      <<"don't expire">>,
-    emqtt:publish(C1, <<"retained/3">>, <<"don't expire">>, [{qos, 0}, {retain, true}]),
+      [{qos, 0}, {retain, true}]),
-    emqtt:publish(C1, <<"$SYS/retained/4">>, <<"don't expire">>, [{qos, 0}, {retain, true}]),
+    emqtt:publish(
+      C1, <<"retained/1">>, #{'Message-Expiry-Interval' => 2},
+      <<"expire">>,
+      [{qos, 0}, {retain, true}]),
+    emqtt:publish(
+      C1, <<"retained/2">>, #{'Message-Expiry-Interval' => 5},
+      <<"don't expire">>,
+      [{qos, 0}, {retain, true}]),
+    emqtt:publish(
+      C1, <<"retained/3">>,
+      <<"don't expire">>,
+      [{qos, 0}, {retain, true}]),
+    emqtt:publish(
+      C1, <<"$SYS/retained/4">>,
+      <<"don't expire">>,
+      [{qos, 0}, {retain, true}]),
 
     {ok, #{}, [0]} = emqtt:subscribe(C1, <<"retained/+">>, 0),
     {ok, #{}, [0]} = emqtt:subscribe(C1, <<"$SYS/retained/+">>, 0),
@@ -210,9 +240,18 @@ t_message_expiry_2(_) ->
 t_clean(_) ->
     {ok, C1} = emqtt:start_link([{clean_start, true}, {proto_ver, v5}]),
     {ok, _} = emqtt:connect(C1),
-    emqtt:publish(C1, <<"retained/0">>, <<"this is a retained message 0">>, [{qos, 0}, {retain, true}]),
+    emqtt:publish(
-    emqtt:publish(C1, <<"retained/1">>, <<"this is a retained message 1">>, [{qos, 0}, {retain, true}]),
+      C1, <<"retained/0">>,
-    emqtt:publish(C1, <<"retained/test/0">>, <<"this is a retained message 2">>, [{qos, 0}, {retain, true}]),
+      <<"this is a retained message 0">>,
+      [{qos, 0}, {retain, true}]),
+    emqtt:publish(
+      C1, <<"retained/1">>,
+      <<"this is a retained message 1">>,
+      [{qos, 0}, {retain, true}]),
+    emqtt:publish(
+      C1, <<"retained/test/0">>,
+      <<"this is a retained message 2">>,
+      [{qos, 0}, {retain, true}]),
     {ok, #{}, [0]} = emqtt:subscribe(C1, <<"retained/#">>, [{qos, 0}, {rh, 0}]),
     ?assertEqual(3, length(receive_messages(3))),
 
@@ -227,7 +266,11 @@ t_stop_publish_clear_msg(_) ->
     emqx_retainer:update_config(#{<<"stop_publish_clear_msg">> => true}),
     {ok, C1} = emqtt:start_link([{clean_start, true}, {proto_ver, v5}]),
     {ok, _} = emqtt:connect(C1),
-    emqtt:publish(C1, <<"retained/0">>, <<"this is a retained message 0">>, [{qos, 0}, {retain, true}]),
+    emqtt:publish(
+      C1, <<"retained/0">>,
+      <<"this is a retained message 0">>,
+      [{qos, 0}, {retain, true}]
+     ),
 
     {ok, #{}, [0]} = emqtt:subscribe(C1, <<"retained/#">>, [{qos, 0}, {rh, 0}]),
     ?assertEqual(1, length(receive_messages(1))),
@@ -239,14 +282,27 @@ t_stop_publish_clear_msg(_) ->
     ok = emqtt:disconnect(C1).
 
 t_flow_control(_) ->
-    emqx_retainer:update_config(#{<<"flow_control">> => #{<<"max_read_number">> => 1,
+    emqx_retainer:update_config(#{<<"flow_control">> =>
+                                  #{<<"max_read_number">> => 1,
                                     <<"msg_deliver_quota">> => 1,
                                     <<"quota_release_interval">> => <<"1s">>}}),
     {ok, C1} = emqtt:start_link([{clean_start, true}, {proto_ver, v5}]),
     {ok, _} = emqtt:connect(C1),
-    emqtt:publish(C1, <<"retained/0">>, <<"this is a retained message 0">>, [{qos, 0}, {retain, true}]),
+    emqtt:publish(
-    emqtt:publish(C1, <<"retained/1">>, <<"this is a retained message 1">>, [{qos, 0}, {retain, true}]),
+      C1, <<"retained/0">>,
-    emqtt:publish(C1, <<"retained/3">>, <<"this is a retained message 3">>, [{qos, 0}, {retain, true}]),
+      <<"this is a retained message 0">>,
+      [{qos, 0}, {retain, true}]
+     ),
+    emqtt:publish(
+      C1, <<"retained/1">>,
+      <<"this is a retained message 1">>,
+      [{qos, 0}, {retain, true}]
+     ),
+    emqtt:publish(
+      C1, <<"retained/3">>,
+      <<"this is a retained message 3">>,
+      [{qos, 0}, {retain, true}]
+     ),
     Begin = erlang:system_time(millisecond),
     {ok, #{}, [0]} = emqtt:subscribe(C1, <<"retained/#">>, [{qos, 0}, {rh, 0}]),
     ?assertEqual(3, length(receive_messages(3))),

apps/emqx_retainer/test/emqx_retainer_mqtt_v5_SUITE.erl

@@ -94,13 +94,23 @@ t_publish_retain_message(_) ->
 
     {ok, Client1} = emqtt:start_link([{proto_ver, v5}]),
     {ok, _} = emqtt:connect(Client1),
-    {ok, _} = emqtt:publish(Client1, Topic, #{}, <<"retained message">>, [{qos, 2}, {retain, true}]),
+    {ok, _} = emqtt:publish(
-    {ok, _} = emqtt:publish(Client1, Topic, #{}, <<"new retained message">>, [{qos, 2}, {retain, true}]),
+                Client1, Topic, #{},
-    {ok, _} = emqtt:publish(Client1, Topic, #{}, <<"not retained message">>, [{qos, 2}, {retain, false}]),
+                <<"retained message">>,
+                [{qos, 2}, {retain, true}]),
+    {ok, _} = emqtt:publish(
+                Client1, Topic, #{},
+                <<"new retained message">>,
+                [{qos, 2}, {retain, true}]),
+    {ok, _} = emqtt:publish(
+                Client1, Topic, #{},
+                <<"not retained message">>,
+                [{qos, 2}, {retain, false}]),
     {ok, _, [2]} = emqtt:subscribe(Client1, Topic, 2),
 
     [Msg] = receive_messages(1),
-    ?assertEqual(<<"new retained message">>, maps:get(payload, Msg)),   %% [MQTT-3.3.1-5] [MQTT-3.3.1-8]
+    %% [MQTT-3.3.1-5] [MQTT-3.3.1-8]
+    ?assertEqual(<<"new retained message">>, maps:get(payload, Msg)),
 
     {ok, _, [0]} = emqtt:unsubscribe(Client1, Topic),
     {ok, _} = emqtt:publish(Client1, Topic, #{}, <<"">>, [{qos, 2}, {retain, true}]),
@@ -113,16 +123,33 @@ t_publish_retain_message(_) ->
 t_publish_message_expiry_interval(_) ->
     {ok, Client1} = emqtt:start_link([{proto_ver, v5}]),
     {ok, _} = emqtt:connect(Client1),
-    {ok, _} = emqtt:publish(Client1, <<"topic/A">>, #{'Message-Expiry-Interval' => 1}, <<"retained message">>, [{qos, 1}, {retain, true}]),
+    {ok, _} = emqtt:publish(
-    {ok, _} = emqtt:publish(Client1, <<"topic/B">>, #{'Message-Expiry-Interval' => 1}, <<"retained message">>, [{qos, 2}, {retain, true}]),
+                Client1, <<"topic/A">>, #{'Message-Expiry-Interval' => 1},
-    {ok, _} = emqtt:publish(Client1, <<"topic/C">>, #{'Message-Expiry-Interval' => 10}, <<"retained message">>, [{qos, 1}, {retain, true}]),
+                <<"retained message">>,
-    {ok, _} = emqtt:publish(Client1, <<"topic/D">>, #{'Message-Expiry-Interval' => 10}, <<"retained message">>, [{qos, 2}, {retain, true}]),
+                [{qos, 1}, {retain, true}]),
+    {ok, _} = emqtt:publish(
+                Client1, <<"topic/B">>, #{'Message-Expiry-Interval' => 1},
+                <<"retained message">>,
+                [{qos, 2}, {retain, true}]),
+    {ok, _} = emqtt:publish(
+                Client1, <<"topic/C">>, #{'Message-Expiry-Interval' => 10},
+                <<"retained message">>,
+                [{qos, 1}, {retain, true}]),
+    {ok, _} = emqtt:publish(
+                Client1, <<"topic/D">>, #{'Message-Expiry-Interval' => 10},
+                <<"retained message">>,
+                [{qos, 2}, {retain, true}]),
     timer:sleep(1500),
     {ok, _, [2]} = emqtt:subscribe(Client1, <<"topic/+">>, 2),
     Msgs = receive_messages(4),
     ?assertEqual(2, length(Msgs)),  %% [MQTT-3.3.2-5]
 
-    L = lists:map(fun(Msg) -> MessageExpiryInterval = maps:get('Message-Expiry-Interval', maps:get(properties, Msg)), MessageExpiryInterval < 10 end, Msgs), 
+    L = lists:map(
+          fun(Msg) ->
+            MessageExpiryInterval = maps:get('Message-Expiry-Interval',
+                                             maps:get(properties, Msg)),
+            MessageExpiryInterval < 10
+          end, Msgs),
     ?assertEqual(2, length(L)),  %% [MQTT-3.3.2-6]
 
     ok = emqtt:disconnect(Client1),
@@ -137,9 +164,21 @@ t_publish_message_expiry_interval(_) ->
 t_subscribe_retain_handing(_) ->
     {ok, Client1} = emqtt:start_link([{proto_ver, v5}]),
     {ok, _} = emqtt:connect(Client1),
-    ok = emqtt:publish(Client1, <<"topic/A">>, #{}, <<"retained message">>, [{qos, 0}, {retain, true}]),
+    ok = emqtt:publish(
-    {ok, _} = emqtt:publish(Client1, <<"topic/B">>, #{}, <<"retained message">>, [{qos, 1}, {retain, true}]),
+           Client1, <<"topic/A">>, #{},
-    {ok, _} = emqtt:publish(Client1, <<"topic/C">>, #{}, <<"retained message">>, [{qos, 2}, {retain, true}]),
+           <<"retained message">>,
+           [{qos, 0}, {retain, true}]
+          ),
+    {ok, _} = emqtt:publish(
+                Client1, <<"topic/B">>, #{},
+                <<"retained message">>,
+                [{qos, 1}, {retain, true}]
+               ),
+    {ok, _} = emqtt:publish(
+                Client1, <<"topic/C">>, #{},
+                <<"retained message">>,
+                [{qos, 2}, {retain, true}]
+               ),
 
     {ok, _, [2]} = emqtt:subscribe(Client1, #{}, [{<<"topic/+">>, [{rh, 1}, {qos, 2}]}]),
     ?assertEqual(3, length(receive_messages(3))),   %% [MQTT-3.3.1-10]

apps/emqx_slow_subs/src/emqx_slow_subs.erl

@@ -104,7 +104,8 @@ on_stats_update(#{clientid := ClientId,
     case ets:lookup(?TOPK_TAB, LastIndex) of
         [#top_k{index = Index}] ->
             %% if last value == the new value, update the type and last_update_time
-            %% XXX for clients whose latency are stable for a long time, is it possible to reduce updates?
+            %% XXX for clients whose latency are stable for a long time, is it
+            %% possible to reduce updates?
             ets:insert(?TOPK_TAB,
                        #top_k{index = Index, type = Type, last_update_time = Ts});
         [_] ->

apps/emqx_slow_subs/src/emqx_slow_subs_api.erl

@@ -72,11 +72,16 @@ schema("/slow_subscriptions/settings") ->
      }.
 
 fields(record) ->
-    [
+    [ {clientid,
-     {clientid, mk(string(), #{desc => <<"the clientid">>})},
+       mk(string(), #{desc => <<"the clientid">>})},
-     {latency, mk(integer(), #{desc => <<"average time for message delivery or time for message expire">>})},
+      {latency,
-     {type, mk(string(), #{desc => <<"type of the latency, could be average or expire">>})},
+       mk(integer(),
-     {last_update_time, mk(integer(), #{desc => <<"the timestamp of last update">>})}
+          #{desc => <<"average time for message delivery or time for message expire">>})},
+      {type,
+       mk(string(),
+          #{desc => <<"type of the latency, could be average or expire">>})},
+      {last_update_time,
+       mk(integer(), #{desc => <<"the timestamp of last update">>})}
     ].
 
 conf_schema() ->

apps/emqx_slow_subs/src/emqx_slow_subs_schema.erl

@@ -23,8 +23,8 @@ fields("slow_subs") ->
     , {notice_interval,
        sc(emqx_schema:duration_ms(),
           "0s",
-          "The interval for pushing statistics table records to the system topic. When set to 0, push is disabled"
+          "The interval for pushing statistics table records to the system topic. "
-          "publish topk list to $SYS/brokers/${node}/slow_subs per notice_interval"
+          "publish topk list to $SYS/brokers/${node}/slow_subs per notice_interval. "
           "publish is disabled if set to 0s."
          )}
     , {notice_qos,