Merge pull request #3546 from emqx/develop

Auto-pull-request-by-2020-06-21
2020-06-21 14:14:52 +08:00 · 2020-06-21 14:14:52 +08:00 · 8e658edb76
parent 6093432834 211c800e24
commit 8e658edb76
69 changed files with 1182 additions and 863 deletions
--- a/.github/workflows/run_test_case.yaml
+++ b/.github/workflows/run_test_case.yaml
@ -13,10 +13,13 @@ jobs:
      
        steps:
        - uses: actions/checkout@v1
-        - name: Run tests
+        - name: Code dialyzer
          run: |
            make xref
+            make dialyzer
            rm -f rebar.lock
+        - name: Run tests
+          run: |
            make eunit
            rm -f rebar.lock
            make ct
--- a/8
+++ b/8
@ -71,6 +71,14 @@ coveralls:
 xref:
 	@rebar3 xref

+.PHONY: dialyzer
+dialyzer:
+	@rebar3 dialyzer
+
+.PHONY: proper
+proper:
+	@rebar3 proper -d test/props -c
+
 .PHONY: deps
 deps:
 	@rebar3 get-deps
--- a/etc/emqx.conf
+++ b/etc/emqx.conf
@ -663,6 +663,11 @@ mqtt.ignore_loop_deliver = false
 ## Value: true | false
 mqtt.strict_mode = false

+## Specify the response information returned to the client
+## 
+## Value: String
+## mqtt.response_information = example
+
 ##--------------------------------------------------------------------
 ## Zones
 ##--------------------------------------------------------------------
@ -868,6 +873,11 @@ zone.external.ignore_loop_deliver = false
 ## Value: true | false
 zone.external.strict_mode = false

+## Specify the response information returned to the client
+## 
+## Value: String
+## zone.external.response_information = example
+
 ##--------------------------------------------------------------------
 ## Internal Zone

@ -954,6 +964,11 @@ zone.internal.ignore_loop_deliver = false
 ## Value: true | false
 zone.internal.strict_mode = false

+## Specify the response information returned to the client
+## 
+## Value: String
+## zone.internal.response_information = example
+
 ## Allow the zone's clients to bypass authentication step
 ##
 ## Value: true | false
@ -1705,16 +1720,6 @@ listener.wss.external.access.1 = allow all
 ## Value: on | off
 listener.wss.external.verify_protocol_header = on

-## See: listener.ws.external.proxy_address_header
-##
-## Value: String
-## listener.wss.external.proxy_address_header = X-Forwarded-For
-
-## See: listener.ws.external.proxy_port_header
-##
-## Value: String
-## listener.wss.external.proxy_port_header = X-Forwarded-Port
-
 ## Enable the Proxy Protocol V1/2 support.
 ##
 ## See: listener.tcp.$name.proxy_protocol
--- a/include/emqx.hrl
+++ b/include/emqx.hrl
@ -62,13 +62,15 @@
          %% Message from
          from :: atom() | binary(),
          %% Message flags
-          flags :: #{atom() => boolean()},
-          %% Message headers, or MQTT 5.0 Properties
-          headers :: map(),
+          flags = #{} :: emqx_types:flags(),
+          %% Message headers. May contain any metadata. e.g. the
+          %% protocol version number, username, peerhost or
+          %% the PUBLISH properties (MQTT 5.0).
+          headers = #{} :: emqx_types:headers(),
          %% Topic that the message is published to
-          topic :: binary(),
+          topic :: emqx_types:topic(),
          %% Message Payload
-          payload :: binary(),
+          payload :: emqx_types:payload(),
          %% Timestamp (Unit: millisecond)
          timestamp :: integer()
         }).
@ -97,7 +99,7 @@
          node_id        :: trie_node_id(),
          edge_count = 0 :: non_neg_integer(),
          topic          :: binary() | undefined,
-          flags          :: list(atom())
+          flags          :: list(atom()) | undefined
        }).

 -record(trie_edge, {
@ -119,7 +121,8 @@
          severity  :: notice | warning | error | critical,
          title     :: iolist(),
          summary   :: iolist(),
-          timestamp :: erlang:timestamp()
+          %% Timestamp (Unit: millisecond)
+          timestamp :: integer() | undefined
        }).

 %%--------------------------------------------------------------------
@ -128,11 +131,11 @@

 -record(plugin, {
          name           :: atom(),
-          dir            :: string(),
+          dir            :: string() | undefined,
          descr          :: string(),
-          vendor         :: string(),
+          vendor         :: string() | undefined,
          active = false :: boolean(),
-          info           :: map(),
+          info   = #{}   :: map(),
          type           :: atom()
        }).

--- a/include/emqx_mqtt.hrl
+++ b/include/emqx_mqtt.hrl
@ -219,9 +219,9 @@
          will_qos     = ?QOS_0,
          will_retain  = false,
          keepalive    = 0,
-          properties   = undefined,
+          properties   = #{},
          clientid     = <<>>,
-          will_props   = undefined,
+          will_props   = #{},
          will_topic   = undefined,
          will_payload = undefined,
          username     = undefined,
@ -231,53 +231,53 @@
 -record(mqtt_packet_connack, {
          ack_flags,
          reason_code,
-          properties
+          properties = #{}
        }).

 -record(mqtt_packet_publish, {
          topic_name,
          packet_id,
-          properties
+          properties = #{}
        }).

 -record(mqtt_packet_puback, {
          packet_id,
          reason_code,
-          properties
+          properties = #{}
        }).

 -record(mqtt_packet_subscribe, {
          packet_id,
-          properties,
+          properties = #{},
          topic_filters
        }).

 -record(mqtt_packet_suback, {
          packet_id,
-          properties,
+          properties = #{},
          reason_codes
        }).

 -record(mqtt_packet_unsubscribe, {
          packet_id,
-          properties,
+          properties = #{},
          topic_filters
        }).

 -record(mqtt_packet_unsuback, {
          packet_id,
-          properties,
+          properties = #{},
          reason_codes
        }).

 -record(mqtt_packet_disconnect, {
          reason_code,
-          properties
+          properties = #{}
        }).

 -record(mqtt_packet_auth, {
          reason_code,
-          properties
+          properties = #{}
        }).

 %%--------------------------------------------------------------------
--- a/include/types.hrl
+++ b/include/types.hrl
@ -22,3 +22,5 @@

 -type(ok_or_error(Value, Reason) :: {ok, Value} | {error, Reason}).

+-type(mfargs() :: {module(), atom(), [term()]}).
+
--- a/priv/emqx.schema
+++ b/priv/emqx.schema
@ -805,6 +805,11 @@ end}.
  {datatype, {enum, [true, false]}}
 ]}.

+%% @doc Specify the response information returned to the client
+{mapping, "mqtt.response_information", "emqx.response_information", [
+  {datatype, string}
+]}.
+
 %%--------------------------------------------------------------------
 %% Zones
 %%--------------------------------------------------------------------
@ -1019,6 +1024,11 @@ end}.
  {datatype, {enum, [true, false]}}
 ]}.

+%% @doc Specify the response information returned to the client
+{mapping, "zone.$name.response_information", "emqx.zones", [
+  {datatype, string}
+]}.
+
 %% @doc Whether to bypass the authentication step
 {mapping, "zone.$name.bypass_auth_plugins", "emqx.zones", [
  {default, false},
@ -1079,6 +1089,8 @@ end}.
                    end;
               ("mountpoint", Val) ->	
                   {mountpoint, iolist_to_binary(Val)};
+               ("response_information", Val) ->
+                   {response_information, iolist_to_binary(Val)};
               (Opt, Val) ->
                    {list_to_atom(Opt), Val}
            end,
--- a/rebar.config
+++ b/rebar.config
@ -1,10 +1,12 @@
 {minimum_otp_vsn, "21.3"}.

+{plugins, [rebar3_proper]}.
+
 {deps,
 [{gproc, {git, "https://github.com/uwiger/gproc", {tag, "0.8.0"}}},
-  {jiffy, {git, "https://github.com/emqx/jiffy", {tag, "1.0.4"}}},
+  {jiffy, {git, "https://github.com/emqx/jiffy", {tag, "1.0.5"}}},
  {cowboy, {git, "https://github.com/emqx/cowboy", {tag, "2.7.1"}}},
-  {esockd, {git, "https://github.com/emqx/esockd", {tag, "5.6.2"}}},
+  {esockd, {git, "https://github.com/emqx/esockd", {tag, "5.7.0"}}},
  {ekka, {git, "https://github.com/emqx/ekka", {tag, "0.7.3"}}},
  {gen_rpc, {git, "https://github.com/emqx/gen_rpc", {tag, "2.4.1"}}},
  {cuttlefish, {git, "https://github.com/emqx/cuttlefish", {tag, "v3.0.0"}}}
@ -39,7 +41,7 @@
    {deps,
     [{bbmustache, "1.7.0"},
      {emqtt, {git, "https://github.com/emqx/emqtt", {tag, "1.2.0"}}},
-      {emqx_ct_helpers, {git, "https://github.com/emqx/emqx-ct-helpers", {tag, "1.2.2"}}}
+      {emqx_ct_helpers, {git, "https://github.com/emqx/emqx-ct-helpers", {tag, "1.3.0"}}}
     ]},
    {erl_opts, [debug_info]}
   ]}
--- a/src/emqx.erl
+++ b/src/emqx.erl
@ -146,7 +146,7 @@ unsubscribe(Topic) ->
 -spec(topics() -> list(emqx_topic:topic())).
 topics() -> emqx_router:topics().

-spec(subscribers(emqx_topic:topic() | string()) -> list(emqx_types:subscriber())).
+-spec(subscribers(emqx_topic:topic() | string()) -> [pid()]).
 subscribers(Topic) ->
    emqx_broker:subscribers(iolist_to_binary(Topic)).

@ -168,7 +168,9 @@ subscribed(SubId, Topic) when is_atom(SubId); is_binary(SubId) ->
 hook(HookPoint, Action) ->
    emqx_hooks:add(HookPoint, Action).

-spec(hook(emqx_hooks:hookpoint(), emqx_hooks:action(), emqx_hooks:filter() | integer())
+-spec(hook(emqx_hooks:hookpoint(),
+           emqx_hooks:action(),
+           emqx_hooks:filter() | integer() | list())
      -> ok | {error, already_exists}).
 hook(HookPoint, Action, Priority) when is_integer(Priority) ->
    emqx_hooks:add(HookPoint, Action, Priority);
@ -182,7 +184,7 @@ hook(HookPoint, Action, InitArgs) when is_list(InitArgs) ->
 hook(HookPoint, Action, Filter, Priority) ->
    emqx_hooks:add(HookPoint, Action, Filter, Priority).

-spec(unhook(emqx_hooks:hookpoint(), emqx_hooks:action()) -> ok).
+-spec(unhook(emqx_hooks:hookpoint(), function() | {module(), atom()}) -> ok).
 unhook(HookPoint, Action) ->
    emqx_hooks:del(HookPoint, Action).

--- a/src/emqx_alarm_handler.erl
+++ b/src/emqx_alarm_handler.erl
@ -171,9 +171,10 @@ encode_alarm({AlarmId, AlarmDesc}) ->
                           }).

 alarm_msg(Topic, Payload) ->
-    Msg = emqx_message:make(?MODULE, Topic, Payload),
-    emqx_message:set_headers(#{'Content-Type' => <<"application/json">>},
-                             emqx_message:set_flag(sys, Msg)).
+    emqx_message:make(?MODULE, 0, Topic, Payload,
+            #{sys => true},
+            #{properties => #{'Content-Type' => <<"application/json">>}}
+        ).

 topic(alert) ->
    emqx_topic:systop(<<"alarms/alert">>);
--- a/src/emqx_boot.erl
+++ b/src/emqx_boot.erl
@ -20,7 +20,7 @@

 -define(BOOT_MODULES, [router, broker, listeners]).

-spec(is_enabled(all|list(router|broker|listeners)) -> boolean()).
+-spec(is_enabled(all|router|broker|listeners) -> boolean()).
 is_enabled(Mod) ->
    (BootMods = boot_modules()) =:= all orelse lists:member(Mod, BootMods).

--- a/src/emqx_broker.erl
+++ b/src/emqx_broker.erl
@ -21,6 +21,7 @@
 -include("emqx.hrl").
 -include("logger.hrl").
 -include("types.hrl").
+-include("emqx_mqtt.hrl").

 -logger_header("[Broker]").

@ -118,12 +119,13 @@ subscribe(Topic) when is_binary(Topic) ->

 -spec(subscribe(emqx_topic:topic(), emqx_types:subid() | emqx_types:subopts()) -> ok).
 subscribe(Topic, SubId) when is_binary(Topic), ?is_subid(SubId) ->
-    subscribe(Topic, SubId, #{qos => 0});
+    subscribe(Topic, SubId, ?DEFAULT_SUBOPTS);
 subscribe(Topic, SubOpts) when is_binary(Topic), is_map(SubOpts) ->
    subscribe(Topic, undefined, SubOpts).

 -spec(subscribe(emqx_topic:topic(), emqx_types:subid(), emqx_types:subopts()) -> ok).
-subscribe(Topic, SubId, SubOpts) when is_binary(Topic), ?is_subid(SubId), is_map(SubOpts) ->
+subscribe(Topic, SubId, SubOpts0) when is_binary(Topic), ?is_subid(SubId), is_map(SubOpts0) ->
+    SubOpts = maps:merge(?DEFAULT_SUBOPTS, SubOpts0),
    case ets:member(?SUBOPTION, {SubPid = self(), Topic}) of
        false -> %% New
            ok = emqx_broker_helper:register_sub(SubPid, SubId),
@ -215,9 +217,8 @@ safe_publish(Msg) when is_record(Msg, message) ->
    catch
        _:Error:Stk->
            ?LOG(error, "Publish error: ~0p~n~s~n~0p",
-                 [Error, emqx_message:format(Msg), Stk])
-    after
-        []
+                 [Error, emqx_message:format(Msg), Stk]),
+            []
    end.

 -compile({inline, [delivery/1]}).
@ -283,7 +284,7 @@ forward(Node, To, Delivery, sync) ->
 dispatch(Topic, #delivery{message = Msg}) ->
    case subscribers(Topic) of
        [] -> ok = emqx_hooks:run('message.dropped', [Msg, #{node => node()}, no_subscribers]),
-              ok = inc_dropped_cnt(Topic),
+              ok = inc_dropped_cnt(Msg),
              {error, no_subscribers};
        [Sub] -> %% optimize?
            dispatch(Sub, Topic, Msg);
@ -322,7 +323,8 @@ inc_dropped_cnt(Msg) ->
    end.

 -compile({inline, [subscribers/1]}).
-spec(subscribers(emqx_topic:topic()) -> [pid()]).
+-spec(subscribers(emqx_topic:topic() | {shard, emqx_topic:topic(), non_neg_integer()})
+      -> [pid()]).
 subscribers(Topic) when is_binary(Topic) ->
    lookup_value(?SUBSCRIBER, Topic, []);
 subscribers(Shard = {shard, _Topic, _I})  ->
@ -367,7 +369,7 @@ subscriptions(SubId) ->
        undefined -> []
    end.

-spec(subscribed(pid(), emqx_topic:topic()) -> boolean()).
+-spec(subscribed(pid() | emqx_types:subid(), emqx_topic:topic()) -> boolean()).
 subscribed(SubPid, Topic) when is_pid(SubPid) ->
    ets:member(?SUBOPTION, {SubPid, Topic});
 subscribed(SubId, Topic) when ?is_subid(SubId) ->
--- a/src/emqx_broker_helper.erl
+++ b/src/emqx_broker_helper.erl
@ -75,7 +75,7 @@ register_sub(SubPid, SubId) when is_pid(SubPid) ->
 lookup_subid(SubPid) when is_pid(SubPid) ->
    emqx_tables:lookup_value(?SUBMON, SubPid).

-spec(lookup_subpid(emqx_types:subid()) -> pid()).
+-spec(lookup_subpid(emqx_types:subid()) -> maybe(pid())).
 lookup_subpid(SubId) ->
    emqx_tables:lookup_value(?SUBID, SubId).

--- a/src/emqx_channel.erl
+++ b/src/emqx_channel.erl
@ -62,9 +62,9 @@
          %% MQTT ClientInfo
          clientinfo :: emqx_types:clientinfo(),
          %% MQTT Session
-          session :: emqx_session:session(),
+          session :: maybe(emqx_session:session()),
          %% Keepalive
-          keepalive :: emqx_keepalive:keepalive(),
+          keepalive :: maybe(emqx_keepalive:keepalive()),
          %% MQTT Will Msg
          will_msg :: maybe(emqx_types:message()),
          %% MQTT Topic Aliases
@ -108,6 +108,8 @@

 -define(INFO_KEYS, [conninfo, conn_state, clientinfo, session, will_msg]).

+-dialyzer({no_match, [shutdown/4, ensure_timer/2, interval/2]}).
+
 %%--------------------------------------------------------------------
 %% Info, Attrs and Caps
 %%--------------------------------------------------------------------
@ -281,14 +283,14 @@ handle_in(Packet = ?PUBLISH_PACKET(_QoS), Channel) ->
            handle_out(disconnect, ReasonCode, Channel)
    end;

-handle_in(?PUBACK_PACKET(PacketId, _ReasonCode), Channel
+handle_in(?PUBACK_PACKET(PacketId, _ReasonCode, Properties), Channel
          = #channel{clientinfo = ClientInfo, session = Session}) ->
    case emqx_session:puback(PacketId, Session) of
        {ok, Msg, NSession} ->
-            ok = after_message_acked(ClientInfo, Msg),
+            ok = after_message_acked(ClientInfo, Msg, Properties),
            {ok, Channel#channel{session = NSession}};
        {ok, Msg, Publishes, NSession} ->
-            ok = after_message_acked(ClientInfo, Msg),
+            ok = after_message_acked(ClientInfo, Msg, Properties),
            handle_out(publish, Publishes, Channel#channel{session = NSession});
        {error, ?RC_PACKET_IDENTIFIER_IN_USE} ->
            ?LOG(warning, "The PUBACK PacketId ~w is inuse.", [PacketId]),
@ -300,11 +302,11 @@ handle_in(?PUBACK_PACKET(PacketId, _ReasonCode), Channel
            {ok, Channel}
    end;

-handle_in(?PUBREC_PACKET(PacketId, _ReasonCode), Channel
+handle_in(?PUBREC_PACKET(PacketId, _ReasonCode, Properties), Channel
          = #channel{clientinfo = ClientInfo, session = Session}) ->
    case emqx_session:pubrec(PacketId, Session) of
        {ok, Msg, NSession} ->
-            ok = after_message_acked(ClientInfo, Msg),
+            ok = after_message_acked(ClientInfo, Msg, Properties),
            NChannel = Channel#channel{session = NSession},
            handle_out(pubrel, {PacketId, ?RC_SUCCESS}, NChannel);
        {error, RC = ?RC_PACKET_IDENTIFIER_IN_USE} ->
@ -347,12 +349,12 @@ handle_in(Packet = ?SUBSCRIBE_PACKET(PacketId, Properties, TopicFilters),
          Channel = #channel{clientinfo = ClientInfo = #{zone := Zone}}) ->
    case emqx_packet:check(Packet) of
        ok -> TopicFilters1 = parse_topic_filters(TopicFilters),
-              TopicFilters2 = enrich_subid(Properties, TopicFilters1),
+              TopicFilters2 = put_subid_in_subopts(Properties, TopicFilters1),
              TopicFilters3 = run_hooks('client.subscribe',
                                        [ClientInfo, Properties],
                                        TopicFilters2
                                       ),
-              {ReasonCodes, NChannel} = process_subscribe(TopicFilters3, Channel),
+              {ReasonCodes, NChannel} = process_subscribe(TopicFilters3, Properties, Channel),
              case emqx_zone:get_env(Zone, acl_deny_action, ignore) =:= disconnect andalso
                   lists:any(fun(ReasonCode) ->
                                 ReasonCode =:= ?RC_NOT_AUTHORIZED
@ -373,7 +375,7 @@ handle_in(Packet = ?UNSUBSCRIBE_PACKET(PacketId, Properties, TopicFilters),
                                        [ClientInfo, Properties],
                                        parse_topic_filters(TopicFilters)
                                       ),
-              {ReasonCodes, NChannel} = process_unsubscribe(TopicFilters1, Channel),
+              {ReasonCodes, NChannel} = process_unsubscribe(TopicFilters1, Properties, Channel),
              handle_out(unsuback, {PacketId, ReasonCodes}, NChannel);
        {error, ReasonCode} ->
            handle_out(disconnect, ReasonCode, Channel)
@ -382,8 +384,8 @@ handle_in(Packet = ?UNSUBSCRIBE_PACKET(PacketId, Properties, TopicFilters),
 handle_in(?PACKET(?PINGREQ), Channel) ->
    {ok, ?PACKET(?PINGRESP), Channel};

-handle_in(?DISCONNECT_PACKET(ReasonCode, Properties), Channel) ->
-    NChannel = maybe_clean_will_msg(ReasonCode, Channel),
+handle_in(?DISCONNECT_PACKET(ReasonCode, Properties), Channel = #channel{conninfo = ConnInfo}) ->
+    NChannel = maybe_clean_will_msg(ReasonCode, Channel#channel{conninfo = ConnInfo#{disconn_props => Properties}}),
    process_disconnect(ReasonCode, Properties, NChannel);

 handle_in(?AUTH_PACKET(), Channel) ->
@ -466,12 +468,23 @@ process_publish(Packet = ?PUBLISH_PACKET(QoS, Topic, PacketId),
            handle_out(disconnect, ReasonCode, NChannel)
    end.

-packet_to_message(Packet, #channel{conninfo = #{proto_ver := ProtoVer},
-                                   clientinfo = ClientInfo =
-                                   #{mountpoint := MountPoint}}) ->
-    emqx_mountpoint:mount(
-      MountPoint, emqx_packet:to_message(
-                    ClientInfo, #{proto_ver => ProtoVer}, Packet)).
+packet_to_message(Packet, #channel{
+                    conninfo = #{proto_ver := ProtoVer},
+                    clientinfo = #{
+                        protocol := Protocol,
+                        clientid := ClientId,
+                        username := Username,
+                        peerhost := PeerHost,
+                        mountpoint := MountPoint
+                    }
+                }) ->
+    emqx_mountpoint:mount(MountPoint,
+        emqx_packet:to_message(
+            Packet, ClientId,
+            #{proto_ver => ProtoVer,
+              protocol => Protocol,
+              username => Username,
+              peerhost => PeerHost})).

 do_publish(_PacketId, Msg = #message{qos = ?QOS_0}, Channel) ->
    _ = emqx_broker:publish(Msg),
@ -504,25 +517,26 @@ do_publish(PacketId, Msg = #message{qos = ?QOS_2},
 puback_reason_code([])    -> ?RC_NO_MATCHING_SUBSCRIBERS;
 puback_reason_code([_|_]) -> ?RC_SUCCESS.

-compile({inline, [after_message_acked/2]}).
-after_message_acked(ClientInfo, Msg) ->
+-compile({inline, [after_message_acked/3]}).
+after_message_acked(ClientInfo, Msg, PubAckProps) ->
    ok = emqx_metrics:inc('messages.acked'),
-    emqx_hooks:run('message.acked', [ClientInfo, Msg]).
+    emqx_hooks:run('message.acked', [ClientInfo,
+        emqx_message:set_header(puback_props, PubAckProps, Msg)]).

 %%--------------------------------------------------------------------
 %% Process Subscribe
 %%--------------------------------------------------------------------

-compile({inline, [process_subscribe/2]}).
-process_subscribe(TopicFilters, Channel) ->
-    process_subscribe(TopicFilters, [], Channel).
+-compile({inline, [process_subscribe/3]}).
+process_subscribe(TopicFilters, SubProps, Channel) ->
+    process_subscribe(TopicFilters, SubProps, Channel, []).

-process_subscribe([], Acc, Channel) ->
+process_subscribe([], _SubProps, Channel, Acc) ->
    {lists:reverse(Acc), Channel};

-process_subscribe([{TopicFilter, SubOpts}|More], Acc, Channel) ->
-    {RC, NChannel} = do_subscribe(TopicFilter, SubOpts, Channel),
-    process_subscribe(More, [RC|Acc], NChannel).
+process_subscribe([{TopicFilter, SubOpts}|More], SubProps, Channel, Acc) ->
+    {RC, NChannel} = do_subscribe(TopicFilter, SubOpts#{sub_props => SubProps}, Channel),
+    process_subscribe(More, SubProps, NChannel, [RC|Acc]).

 do_subscribe(TopicFilter, SubOpts = #{qos := QoS}, Channel =
             #channel{clientinfo = ClientInfo = #{mountpoint := MountPoint},
@ -557,22 +571,22 @@ process_force_subscribe(Subscriptions, Channel =
 %% Process Unsubscribe
 %%--------------------------------------------------------------------

-compile({inline, [process_unsubscribe/2]}).
-process_unsubscribe(TopicFilters, Channel) ->
-    process_unsubscribe(TopicFilters, [], Channel).
+-compile({inline, [process_unsubscribe/3]}).
+process_unsubscribe(TopicFilters, UnSubProps, Channel) ->
+    process_unsubscribe(TopicFilters, UnSubProps, Channel, []).

-process_unsubscribe([], Acc, Channel) ->
+process_unsubscribe([], _UnSubProps, Channel, Acc) ->
    {lists:reverse(Acc), Channel};

-process_unsubscribe([{TopicFilter, SubOpts}|More], Acc, Channel) ->
-    {RC, NChannel} = do_unsubscribe(TopicFilter, SubOpts, Channel),
-    process_unsubscribe(More, [RC|Acc], NChannel).
+process_unsubscribe([{TopicFilter, SubOpts}|More], UnSubProps, Channel, Acc) ->
+    {RC, NChannel} = do_unsubscribe(TopicFilter, SubOpts#{unsub_props => UnSubProps}, Channel),
+    process_unsubscribe(More, UnSubProps, NChannel, [RC|Acc]).

-do_unsubscribe(TopicFilter, _SubOpts, Channel =
+do_unsubscribe(TopicFilter, SubOpts, Channel =
               #channel{clientinfo = ClientInfo = #{mountpoint := MountPoint},
                        session = Session}) ->
    TopicFilter1 = emqx_mountpoint:mount(MountPoint, TopicFilter),
-    case emqx_session:unsubscribe(ClientInfo, TopicFilter1, Session) of
+    case emqx_session:unsubscribe(ClientInfo, TopicFilter1, SubOpts, Session) of
        {ok, NSession} ->
            {?RC_SUCCESS, Channel#channel{session = NSession}};
        {error, RC} -> {RC, Channel}
@ -582,9 +596,9 @@ do_unsubscribe(TopicFilter, _SubOpts, Channel =
 process_force_unsubscribe(Subscriptions, Channel =
               #channel{clientinfo = ClientInfo = #{mountpoint := MountPoint},
                        session = Session}) ->
-    lists:foldl(fun({TopicFilter, _SubOpts}, {ReasonCodes, ChannelAcc}) ->
+    lists:foldl(fun({TopicFilter, SubOpts}, {ReasonCodes, ChannelAcc}) ->
                    NTopicFilter = emqx_mountpoint:mount(MountPoint, TopicFilter),
-                    case emqx_session:unsubscribe(ClientInfo, NTopicFilter, Session) of
+                    case emqx_session:unsubscribe(ClientInfo, NTopicFilter, SubOpts, Session) of
                        {ok, NSession} ->
                            {ReasonCodes ++ [?RC_SUCCESS], ChannelAcc#channel{session = NSession}};
                        {error, ReasonCode} ->
@ -662,6 +676,7 @@ not_nacked({deliver, _Topic, Msg}) ->
 handle_out(connack, {?RC_SUCCESS, SP, Props}, Channel = #channel{conninfo = ConnInfo}) ->
    AckProps = run_fold([fun enrich_connack_caps/2,
                         fun enrich_server_keepalive/2,
+                         fun enrich_response_information/2,
                         fun enrich_assigned_clientid/2
                        ], Props, Channel),
    NAckProps = run_hooks('client.connack', [ConnInfo, emqx_reason_codes:name(?RC_SUCCESS)], AckProps),
@ -806,7 +821,8 @@ return_unsuback(Packet, Channel) ->

 -spec(handle_call(Req :: term(), channel())
      -> {reply, Reply :: term(), channel()}
-       | {shutdown, Reason :: term(), Reply :: term(), channel()}).
+       | {shutdown, Reason :: term(), Reply :: term(), channel()}
+       | {shutdown, Reason :: term(), Reply :: term(), emqx_types:packet(), channel()}).
 handle_call(kick, Channel) ->
    Channel1 = ensure_disconnected(kicked, Channel),
    disconnect_and_shutdown(kicked, ok, Channel1);
@ -844,7 +860,7 @@ handle_info({subscribe, TopicFilters}, Channel = #channel{clientinfo = ClientInf
                              [ClientInfo, #{'Internal' => true}],
                              parse_topic_filters(TopicFilters)
                             ),
-    {_ReasonCodes, NChannel} = process_subscribe(TopicFilters1, Channel),
+    {_ReasonCodes, NChannel} = process_subscribe(TopicFilters1, #{}, Channel),
    {ok, NChannel};

 handle_info({force_subscribe, TopicFilters}, Channel) ->
@ -856,7 +872,7 @@ handle_info({unsubscribe, TopicFilters}, Channel = #channel{clientinfo = ClientI
                              [ClientInfo, #{'Internal' => true}],
                              parse_topic_filters(TopicFilters)
                             ),
-    {_ReasonCodes, NChannel} = process_unsubscribe(TopicFilters1, Channel),
+    {_ReasonCodes, NChannel} = process_unsubscribe(TopicFilters1, #{}, Channel),
    {ok, NChannel};

 handle_info({force_unsubscribe, TopicFilters}, Channel) ->
@ -924,9 +940,6 @@ handle_timeout(_TRef, retry_delivery,
    case emqx_session:retry(Session) of
        {ok, NSession} ->
            {ok, clean_timer(retry_timer, Channel#channel{session = NSession})};
-        {ok, Publishes, NSession} ->
-            NChannel = Channel#channel{session = NSession},
-            handle_out(publish, Publishes, reset_timer(retry_timer, NChannel));
        {ok, Publishes, Timeout, NSession} ->
            NChannel = Channel#channel{session = NSession},
            handle_out(publish, Publishes, reset_timer(retry_timer, Timeout, NChannel))
@ -1001,6 +1014,7 @@ interval(will_timer, #channel{will_msg = WillMsg}) ->
 %% Terminate
 %%--------------------------------------------------------------------

+-spec(terminate(any(), channel()) -> ok).
 terminate(_, #channel{conn_state = idle}) -> ok;
 terminate(normal, Channel) ->
    run_terminate_hook(normal, Channel);
@ -1176,7 +1190,7 @@ enhanced_auth(?CONNECT_PACKET(#mqtt_packet_connect{
    end;

 enhanced_auth(?AUTH_PACKET(_ReasonCode, Properties), Channel = #channel{conninfo = ConnInfo}) ->
-    AuthMethod = maps:get('Authentication-Method', maps:get(conn_props, ConnInfo), undefined),
+    AuthMethod = emqx_mqtt_props:get('Authentication-Method', emqx_mqtt_props:get(conn_props, ConnInfo, #{}), undefined),
    NAuthMethod = emqx_mqtt_props:get('Authentication-Method', Properties, undefined),
    AuthData = emqx_mqtt_props:get('Authentication-Data', Properties, undefined),
    case NAuthMethod =:= undefined orelse NAuthMethod =/= AuthMethod of
@ -1329,9 +1343,9 @@ check_sub_caps(TopicFilter, SubOpts, #channel{clientinfo = #{zone := Zone}}) ->
 %%--------------------------------------------------------------------
 %% Enrich SubId

-enrich_subid(#{'Subscription-Identifier' := SubId}, TopicFilters) ->
+put_subid_in_subopts(#{'Subscription-Identifier' := SubId}, TopicFilters) ->
    [{Topic, SubOpts#{subid => SubId}} || {Topic, SubOpts} <- TopicFilters];
-enrich_subid(_Properties, TopicFilters) -> TopicFilters.
+put_subid_in_subopts(_Properties, TopicFilters) -> TopicFilters.

 %%--------------------------------------------------------------------
 %% Enrich SubOpts
@ -1380,6 +1394,16 @@ enrich_server_keepalive(AckProps, #channel{clientinfo = #{zone := Zone}}) ->
        Keepalive -> AckProps#{'Server-Keep-Alive' => Keepalive}
    end.

+%%--------------------------------------------------------------------
+%% Enrich response information
+
+enrich_response_information(AckProps, #channel{conninfo = #{conn_props := ConnProps},
+                                               clientinfo = #{zone := Zone}}) ->
+    case emqx_mqtt_props:get('Request-Response-Information', ConnProps, 0) of
+        0 -> AckProps;
+        1 -> AckProps#{'Response-Information' => emqx_zone:response_information(Zone)}
+    end.
+
 %%--------------------------------------------------------------------
 %% Enrich Assigned ClientId

@ -1490,7 +1514,7 @@ mabye_publish_will_msg(Channel = #channel{will_msg = WillMsg}) ->
    end.

 will_delay_interval(WillMsg) ->
-    emqx_message:get_header('Will-Delay-Interval', WillMsg, 0).
+    maps:get('Will-Delay-Interval', emqx_message:get_header(properties, WillMsg), 0).

 publish_will_msg(Msg) -> emqx_broker:publish(Msg).

--- a/src/emqx_cm.erl
+++ b/src/emqx_cm.erl
@ -107,7 +107,7 @@ start_link() ->
 register_channel(ClientId, Info = #{conninfo := ConnInfo}, Stats) ->
    Chan = {ClientId, ChanPid = self()},
    true = ets:insert(?CHAN_INFO_TAB, {Chan, Info, Stats}),
-    register_channel(ClientId, ChanPid, ConnInfo);
+    register_channel_(ClientId, ChanPid, ConnInfo).

 %% @private
 %% @doc Register a channel with pid and conn_mod.
@ -117,7 +117,7 @@ register_channel(ClientId, Info = #{conninfo := ConnInfo}, Stats) ->
 %% the conn_mod first for taking up the clientid access right.
 %%
 %% Note that: It should be called on a lock transaction
-register_channel(ClientId, ChanPid, #{conn_mod := ConnMod}) when is_pid(ChanPid) ->
+register_channel_(ClientId, ChanPid, #{conn_mod := ConnMod}) when is_pid(ChanPid) ->
    Chan = {ClientId, ChanPid},
    true = ets:insert(?CHAN_TAB, Chan),
    true = ets:insert(?CHAN_CONN_TAB, {Chan, ConnMod}),
@ -211,7 +211,7 @@ open_session(true, ClientInfo = #{clientid := ClientId}, ConnInfo) ->
    CleanStart = fun(_) ->
                     ok = discard_session(ClientId),
                     Session = create_session(ClientInfo, ConnInfo),
-                     register_channel(ClientId, Self, ConnInfo),
+                     register_channel_(ClientId, Self, ConnInfo),
                     {ok, #{session => Session, present => false}}
                 end,
    emqx_cm_locker:trans(ClientId, CleanStart);
@ -223,13 +223,13 @@ open_session(false, ClientInfo = #{clientid := ClientId}, ConnInfo) ->
                          {ok, ConnMod, ChanPid, Session} ->
                              ok = emqx_session:resume(ClientInfo, Session),
                              Pendings = ConnMod:call(ChanPid, {takeover, 'end'}),
-                              register_channel(ClientId, Self, ConnInfo),
+                              register_channel_(ClientId, Self, ConnInfo),
                              {ok, #{session  => Session,
                                     present  => true,
                                     pendings => Pendings}};
                          {error, not_found} ->
                              Session = create_session(ClientInfo, ConnInfo),
-                              register_channel(ClientId, Self, ConnInfo),
+                              register_channel_(ClientId, Self, ConnInfo),
                              {ok, #{session => Session, present => false}}
                      end
                  end,
@ -243,7 +243,8 @@ create_session(ClientInfo, ConnInfo) ->

 %% @doc Try to takeover a session.
 -spec(takeover_session(emqx_types:clientid())
-      -> {ok, emqx_session:session()} | {error, Reason :: term()}).
+      -> {error, term()}
+       | {ok, atom(), pid(), emqx_session:session()}).
 takeover_session(ClientId) ->
    case lookup_channels(ClientId) of
        [] -> {error, not_found};
--- a/src/emqx_connection.erl
+++ b/src/emqx_connection.erl
@ -103,6 +103,13 @@

 -define(ENABLED(X), (X =/= undefined)).

+-dialyzer({no_match, [info/2]}).
+-dialyzer({nowarn_function, [ init/4
+                            , init_state/3
+                            , run_loop/2
+                            , system_terminate/4
+                            ]}).
+
 -spec(start_link(esockd:transport(), esockd:socket(), proplists:proplist())
      -> {ok, pid()}).
 start_link(Transport, Socket, Options) ->
--- a/src/emqx_ctl.erl
+++ b/src/emqx_ctl.erl
@ -159,7 +159,7 @@ format(Msg) ->
 format(Format, Args) ->
    lists:flatten(io_lib:format(Format, Args)).

-spec(format_usage([cmd_usage()]) -> ok).
+-spec(format_usage([cmd_usage()]) -> [string()]).
 format_usage(UsageList) ->
    lists:map(
        fun({CmdParams, Desc}) ->
--- a/src/emqx_frame.erl
+++ b/src/emqx_frame.erl
@ -42,10 +42,10 @@
                     version => emqx_types:version()
                    }).

-opaque(parse_state() :: {none, options()} | cont_fun()).
+-type(parse_state() :: {none, options()} | cont_fun()).

-opaque(parse_result() :: {more, cont_fun()}
-                        | {ok, emqx_types:packet(), binary(), parse_state()}).
+-type(parse_result() :: {more, cont_fun()}
+                      | {ok, emqx_types:packet(), binary(), parse_state()}).

 -type(cont_fun() :: fun((binary()) -> parse_result())).

@ -59,6 +59,8 @@
          version     => ?MQTT_PROTO_V4
         }).

+-dialyzer({no_match, [serialize_utf8_string/2]}).
+
 %%--------------------------------------------------------------------
 %% Init Parse State
 %%--------------------------------------------------------------------
@ -307,7 +309,7 @@ parse_packet_id(<<PacketId:16/big, Rest/binary>>) ->
    {PacketId, Rest}.

 parse_properties(Bin, Ver) when Ver =/= ?MQTT_PROTO_V5 ->
-    {undefined, Bin};
+    {#{}, Bin};
 %% TODO: version mess?
 parse_properties(<<>>, ?MQTT_PROTO_V5) ->
    {#{}, <<>>};
--- a/src/emqx_gen_mod.erl
+++ b/src/emqx_gen_mod.erl
@ -16,21 +16,8 @@

 -module(emqx_gen_mod).

-ifdef(use_specs).
-
 -callback(load(Opts :: any()) -> ok | {error, term()}).

 -callback(unload(State :: term()) -> term()).

 -callback(description() -> any()).
-
-else.
-
-export([behaviour_info/1]).
-
-behaviour_info(callbacks) ->
-    [{load, 1}, {unload, 1}];
-behaviour_info(_Other) ->
-    undefined.
-
-endif.
--- a/src/emqx_hooks.erl
+++ b/src/emqx_hooks.erl
@ -60,12 +60,12 @@
 %%     equal priority values.

 -type(hookpoint() :: atom()).
-type(action() :: function() | mfa()).
-type(filter() :: function() | mfa()).
+-type(action() :: function() | {function(), [term()]} | mfargs()).
+-type(filter() :: function() | mfargs()).

 -record(callback, {
          action :: action(),
-          filter :: filter(),
+          filter :: maybe(filter()),
          priority :: integer()
         }).

@ -112,7 +112,7 @@ add(HookPoint, Action, Filter, Priority) when is_integer(Priority) ->
    add(HookPoint, #callback{action = Action, filter = Filter, priority = Priority}).

 %% @doc Unregister a callback.
-spec(del(hookpoint(), action()) -> ok).
+-spec(del(hookpoint(), function() | {module(), atom()}) -> ok).
 del(HookPoint, Action) ->
    gen_server:cast(?SERVER, {del, HookPoint, Action}).

--- a/src/emqx_json.erl
+++ b/src/emqx_json.erl
@ -103,16 +103,13 @@ safe_decode(Json, Opts) ->
          , from_ejson/1
          ]}).

-to_ejson([[{_,_}|_]|_] = L) ->
-    [to_ejson(E) || E <- L];
 to_ejson([{_, _}|_] = L) ->
-    lists:foldl(
-      fun({Name, Value}, Acc) ->
-        Acc#{Name => to_ejson(Value)}
-      end, #{}, L);
+    {[{K, to_ejson(V)} || {K, V} <- L ]};
+to_ejson(L) when is_list(L) ->
+    [to_ejson(E) || E <- L];
 to_ejson(T) -> T.

-from_ejson([{_}|_] = L) ->
+from_ejson(L) when is_list(L) ->
    [from_ejson(E) || E <- L];
 from_ejson({L}) ->
    [{Name, from_ejson(Value)} || {Name, Value} <- L];
--- a/src/emqx_logger.erl
+++ b/src/emqx_logger.erl
@ -221,7 +221,7 @@ trans([{eof, L} | AST], LogHeader, ResAST) ->
 trans([{attribute, _, module, _Mod} = M | AST], Header, ResAST) ->
    trans(AST, Header, [export_header_fun(), M | ResAST]);
 trans([{attribute, _, logger_header, Header} | AST], _, ResAST) ->
-    io_lib:printable_list(Header) orelse error({invalid_string, Header}),
+    io_lib:printable_list(Header) orelse erlang:error({invalid_string, Header}),
    trans(AST, Header, ResAST);
 trans([F | AST], LogHeader, ResAST) ->
    trans(AST, LogHeader, [F | ResAST]).
--- a/src/emqx_logger_formatter.erl
+++ b/src/emqx_logger_formatter.erl
@ -253,9 +253,7 @@ format_time(SysTime,#{})
    {Date, _Time = {H, Mi, S}} = calendar:system_time_to_local_time(SysTime, microsecond),
    format_time({Date, {H, Mi, S, Ms}}).
 format_time({{Y, M, D}, {H, Mi, S, Ms}}) ->
-    io_lib:format("~b-~2..0b-~2..0b ~2..0b:~2..0b:~2..0b.~3..0b", [Y, M, D, H, Mi, S, Ms]);
-format_time({{Y, M, D}, {H, Mi, S}}) ->
-    io_lib:format("~b-~2..0b-~2..0b ~2..0b:~2..0b:~2..0b", [Y, M, D, H, Mi, S]).
+    io_lib:format("~b-~2..0b-~2..0b ~2..0b:~2..0b:~2..0b.~3..0b", [Y, M, D, H, Mi, S, Ms]).

 format_mfa({M,F,A},_) when is_atom(M), is_atom(F), is_integer(A) ->
    atom_to_list(M)++":"++atom_to_list(F)++"/"++integer_to_list(A);
--- a/src/emqx_message.erl
+++ b/src/emqx_message.erl
@ -26,6 +26,8 @@
 -export([ make/2
        , make/3
        , make/4
+        , make/6
+        , make/7
        ]).

 %% Fields
@ -69,8 +71,6 @@

 -export([format/1]).

-type(flag() :: atom()).
-
 -spec(make(emqx_topic:topic(), emqx_types:payload()) -> emqx_types:message()).
 make(Topic, Payload) ->
    make(undefined, Topic, Payload).
@ -95,6 +95,47 @@ make(From, QoS, Topic, Payload) when ?QOS_0 =< QoS, QoS =< ?QOS_2 ->
             timestamp = Now
            }.

+-spec(make(emqx_types:clientid(),
+           emqx_types:qos(),
+           emqx_topic:topic(),
+           emqx_types:payload(),
+           emqx_types:flags(),
+           emqx_types:headers()) -> emqx_types:message()).
+make(From, QoS, Topic, Payload, Flags, Headers)
+        when ?QOS_0 =< QoS, QoS =< ?QOS_2,
+             is_map(Flags), is_map(Headers) ->
+    Now = erlang:system_time(millisecond),
+    #message{id = emqx_guid:gen(),
+             qos = QoS,
+             from = From,
+             flags = Flags,
+             headers = Headers,
+             topic = Topic,
+             payload = Payload,
+             timestamp = Now
+            }.
+
+-spec(make(MsgId :: binary(),
+           emqx_types:clientid(),
+           emqx_types:qos(),
+           emqx_topic:topic(),
+           emqx_types:payload(),
+           emqx_types:flags(),
+           emqx_types:headers()) -> emqx_types:message()).
+make(MsgId, From, QoS, Topic, Payload, Flags, Headers)
+        when ?QOS_0 =< QoS, QoS =< ?QOS_2,
+             is_map(Flags), is_map(Headers) ->
+    Now = erlang:system_time(millisecond),
+    #message{id = MsgId,
+             qos = QoS,
+             from = From,
+             flags = Flags,
+             headers = Headers,
+             topic = Topic,
+             payload = Payload,
+             timestamp = Now
+            }.
+
 -spec(id(emqx_types:message()) -> maybe(binary())).
 id(#message{id = Id}) -> Id.

@ -126,39 +167,29 @@ clean_dup(Msg = #message{flags = Flags = #{dup := true}}) ->
 clean_dup(Msg) -> Msg.

 -spec(set_flags(map(), emqx_types:message()) -> emqx_types:message()).
-set_flags(Flags, Msg = #message{flags = undefined}) when is_map(Flags) ->
-    Msg#message{flags = Flags};
 set_flags(New, Msg = #message{flags = Old}) when is_map(New) ->
    Msg#message{flags = maps:merge(Old, New)}.

-spec(get_flag(flag(), emqx_types:message()) -> boolean()).
-get_flag(_Flag, #message{flags = undefined}) ->
-    false;
+-spec(get_flag(emqx_types:flag(), emqx_types:message()) -> boolean()).
 get_flag(Flag, Msg) ->
    get_flag(Flag, Msg, false).

-get_flag(_Flag, #message{flags = undefined}, Default) ->
-    Default;
 get_flag(Flag, #message{flags = Flags}, Default) ->
    maps:get(Flag, Flags, Default).

 -spec(get_flags(emqx_types:message()) -> maybe(map())).
 get_flags(#message{flags = Flags}) -> Flags.

-spec(set_flag(flag(), emqx_types:message()) -> emqx_types:message()).
-set_flag(Flag, Msg = #message{flags = undefined}) when is_atom(Flag) ->
-    Msg#message{flags = #{Flag => true}};
+-spec(set_flag(emqx_types:flag(), emqx_types:message()) -> emqx_types:message()).
 set_flag(Flag, Msg = #message{flags = Flags}) when is_atom(Flag) ->
    Msg#message{flags = maps:put(Flag, true, Flags)}.

-spec(set_flag(flag(), boolean() | integer(), emqx_types:message())
+-spec(set_flag(emqx_types:flag(), boolean() | integer(), emqx_types:message())
      -> emqx_types:message()).
-set_flag(Flag, Val, Msg = #message{flags = undefined}) when is_atom(Flag) ->
-    Msg#message{flags = #{Flag => Val}};
 set_flag(Flag, Val, Msg = #message{flags = Flags}) when is_atom(Flag) ->
    Msg#message{flags = maps:put(Flag, Val, Flags)}.

-spec(unset_flag(flag(), emqx_types:message()) -> emqx_types:message()).
+-spec(unset_flag(emqx_types:flag(), emqx_types:message()) -> emqx_types:message()).
 unset_flag(Flag, Msg = #message{flags = Flags}) ->
    case maps:is_key(Flag, Flags) of
        true  -> Msg#message{flags = maps:remove(Flag, Flags)};
@ -166,8 +197,6 @@ unset_flag(Flag, Msg = #message{flags = Flags}) ->
    end.

 -spec(set_headers(map(), emqx_types:message()) -> emqx_types:message()).
-set_headers(Headers, Msg = #message{headers = undefined}) when is_map(Headers) ->
-    Msg#message{headers = Headers};
 set_headers(New, Msg = #message{headers = Old}) when is_map(New) ->
    Msg#message{headers = maps:merge(Old, New)}.

@ -175,25 +204,17 @@ set_headers(New, Msg = #message{headers = Old}) when is_map(New) ->
 get_headers(Msg) -> Msg#message.headers.

 -spec(get_header(term(), emqx_types:message()) -> term()).
-get_header(_Hdr, #message{headers = undefined}) ->
-    undefined;
 get_header(Hdr, Msg) ->
    get_header(Hdr, Msg, undefined).
 -spec(get_header(term(), emqx_types:message(), term()) -> term()).
-get_header(_Hdr, #message{headers = undefined}, Default) ->
-    Default;
 get_header(Hdr, #message{headers = Headers}, Default) ->
    maps:get(Hdr, Headers, Default).

 -spec(set_header(term(), term(), emqx_types:message()) -> emqx_types:message()).
-set_header(Hdr, Val, Msg = #message{headers = undefined}) ->
-    Msg#message{headers = #{Hdr => Val}};
 set_header(Hdr, Val, Msg = #message{headers = Headers}) ->
    Msg#message{headers = maps:put(Hdr, Val, Headers)}.

 -spec(remove_header(term(), emqx_types:message()) -> emqx_types:message()).
-remove_header(_Hdr, Msg = #message{headers = undefined}) ->
-    Msg;
 remove_header(Hdr, Msg = #message{headers = Headers}) ->
    case maps:is_key(Hdr, Headers) of
        true  -> Msg#message{headers = maps:remove(Hdr, Headers)};
@ -201,18 +222,18 @@ remove_header(Hdr, Msg = #message{headers = Headers}) ->
    end.

 -spec(is_expired(emqx_types:message()) -> boolean()).
-is_expired(#message{headers = #{'Message-Expiry-Interval' := Interval},
+is_expired(#message{headers = #{properties := #{'Message-Expiry-Interval' := Interval}},
                    timestamp = CreatedAt}) ->
    elapsed(CreatedAt) > timer:seconds(Interval);
 is_expired(_Msg) -> false.

 -spec(update_expiry(emqx_types:message()) -> emqx_types:message()).
-update_expiry(Msg = #message{headers = #{'Message-Expiry-Interval' := Interval},
+update_expiry(Msg = #message{headers = #{properties := Props = #{'Message-Expiry-Interval' := Interval}},
                             timestamp = CreatedAt}) ->
    case elapsed(CreatedAt) of
        Elapsed when Elapsed > 0 ->
            Interval1 = max(1, Interval - (Elapsed div 1000)),
-            set_header('Message-Expiry-Interval', Interval1, Msg);
+            set_header(properties, Props#{'Message-Expiry-Interval' => Interval1}, Msg);
        _ -> Msg
    end;
 update_expiry(Msg) -> Msg.
@ -229,20 +250,20 @@ to_packet(PacketId, Msg = #message{qos = QoS, headers = Headers,
                                               },
                 variable = #mqtt_packet_publish{topic_name = Topic,
                                                 packet_id  = PacketId,
-                                                 properties = props(Headers)
+                                                 properties = filter_pub_props(maps:get(properties, Headers, #{}))
                                                },
                 payload  = Payload
                }.

-props(undefined) -> undefined;
-props(Headers)   -> maps:with(['Payload-Format-Indicator',
-                               'Response-Topic',
-                               'Correlation-Data',
-                               'User-Property',
-                               'Subscription-Identifier',
-                               'Content-Type',
-                               'Message-Expiry-Interval'
-                              ], Headers).
+filter_pub_props(Props) ->
+    maps:with(['Payload-Format-Indicator',
+               'Message-Expiry-Interval',
+               'Response-Topic',
+               'Correlation-Data',
+               'User-Property',
+               'Subscription-Identifier',
+               'Content-Type'
+              ], Props).

 %% @doc Message to map
 -spec(to_map(emqx_types:message()) -> map()).
@ -267,7 +288,7 @@ to_map(#message{
     }.

 %% @doc Message to tuple list
-spec(to_list(emqx_types:message()) -> map()).
+-spec(to_list(emqx_types:message()) -> list()).
 to_list(Msg) ->
    lists:zip(record_info(fields, message), tl(tuple_to_list(Msg))).

@ -279,8 +300,6 @@ format(#message{id = Id, qos = QoS, topic = Topic, from = From, flags = Flags, h
    io_lib:format("Message(Id=~s, QoS=~w, Topic=~s, From=~p, Flags=~s, Headers=~s)",
                  [Id, QoS, Topic, From, format(flags, Flags), format(headers, Headers)]).

-format(_, undefined) ->
-    "";
 format(flags, Flags) ->
    io_lib:format("~p", [[Flag || {Flag, true} <- maps:to_list(Flags)]]);
 format(headers, Headers) ->
--- a/src/emqx_misc.erl
+++ b/src/emqx_misc.erl
@ -62,11 +62,17 @@ maybe_apply(_Fun, undefined) -> undefined;
 maybe_apply(Fun, Arg) when is_function(Fun) ->
    erlang:apply(Fun, [Arg]).

-spec(compose(list(F)) -> G when F :: fun((any()) -> any()),
-                                 G :: fun((any()) -> any())).
+-spec(compose(list(F)) -> G
+  when F :: fun((any()) -> any()),
+       G :: fun((any()) -> any())).
 compose([F|More]) -> compose(F, More).

-spec(compose(fun((X) -> Y), fun((Y) -> Z)) -> fun((X) -> Z)).
+-spec(compose(F, G|[Gs]) -> C
+  when F :: fun((X1) -> X2),
+       G :: fun((X2) -> X3),
+       Gs :: [fun((Xn) -> Xn1)],
+       C :: fun((X1) -> Xm),
+       X3 :: any(), Xn :: any(), Xn1 :: any(), Xm :: any()).
 compose(F, G) when is_function(G) -> fun(X) -> G(F(X)) end;
 compose(F, [G]) -> compose(F, G);
 compose(F, [G|More]) -> compose(compose(F, G), More).
--- a/src/emqx_mod_acl_internal.erl
+++ b/src/emqx_mod_acl_internal.erl
@ -33,8 +33,6 @@
        , description/0
        ]).

-define(MFA(M, F, A), {M, F, A}).
-
 -type(acl_rules() :: #{publish   => [emqx_access_rule:rule()],
                       subscribe => [emqx_access_rule:rule()]}).

@ -44,11 +42,10 @@

 load(_Env) ->
    Rules = rules_from_file(emqx:get_env(acl_file)),
-    emqx_hooks:add('client.check_acl', ?MFA(?MODULE, check_acl, [Rules]),  -1).
+    emqx_hooks:add('client.check_acl', {?MODULE, check_acl, [Rules]},  -1).

 unload(_Env) ->
-    Rules = rules_from_file(emqx:get_env(acl_file)),
-    emqx_hooks:del('client.check_acl', ?MFA(?MODULE, check_acl, [Rules])).
+    emqx_hooks:del('client.check_acl', {?MODULE, check_acl}).

 reload(_Env) ->
    emqx_acl_cache:is_enabled() andalso (
--- a/src/emqx_mod_delayed.erl
+++ b/src/emqx_mod_delayed.erl
@ -61,7 +61,7 @@ load(_Env) ->

 -spec(unload(list()) -> ok).
 unload(_Env) ->
-    emqx:unhook('message.publish', {?MODULE, on_message_publish, []}),
+    emqx:unhook('message.publish', {?MODULE, on_message_publish}),
    emqx_mod_sup:stop_child(?MODULE).

 description() ->
@ -83,21 +83,13 @@ on_message_publish(Msg = #message{id = Id, topic = <<"$delayed/", Topic/binary>>
                    end
            end,
    PubMsg = Msg#message{topic = Topic1},
-    Headers = case PubMsg#message.headers of
-        undefined -> #{};
-        Headers0 -> Headers0
-    end,
-    ok = store(#delayed_message{key = {PubAt, delayed_mid(Id)}, msg = PubMsg}),
+    Headers = PubMsg#message.headers,
+    ok = store(#delayed_message{key = {PubAt, Id}, msg = PubMsg}),
    {stop, PubMsg#message{headers = Headers#{allow_publish => false}}};

 on_message_publish(Msg) ->
    {ok, Msg}.

-%% @private
-delayed_mid(undefined) ->
-    emqx_guid:gen();
-delayed_mid(MsgId) -> MsgId.
-
 %%--------------------------------------------------------------------
 %% Start delayed publish server
 %%--------------------------------------------------------------------
--- a/src/emqx_mod_topic_metrics.erl
+++ b/src/emqx_mod_topic_metrics.erl
@ -97,14 +97,14 @@

 load(_Env) ->
    emqx_mod_sup:start_child(?MODULE, worker),
-    emqx:hook('message.publish', fun ?MODULE:on_message_publish/1, []),
-    emqx:hook('message.dropped', fun ?MODULE:on_message_dropped/3, []),
-    emqx:hook('message.delivered', fun ?MODULE:on_message_delivered/2, []).
+    emqx:hook('message.publish',   {?MODULE, on_message_publish, []}),
+    emqx:hook('message.dropped',   {?MODULE, on_message_dropped, []}),
+    emqx:hook('message.delivered', {?MODULE, on_message_delivered, []}).

 unload(_Env) ->
-    emqx:unhook('message.publish', fun ?MODULE:on_message_publish/1),
-    emqx:unhook('message.dropped', fun ?MODULE:on_message_dropped/3),
-    emqx:unhook('message.delivered', fun ?MODULE:on_message_delivered/2),
+    emqx:unhook('message.publish',   {?MODULE, on_message_publish}),
+    emqx:unhook('message.dropped',   {?MODULE, on_message_dropped}),
+    emqx:unhook('message.delivered', {?MODULE, on_message_delivered}),
    emqx_mod_sup:stop_child(?MODULE).

 description() ->
--- a/src/emqx_mqtt_caps.erl
+++ b/src/emqx_mqtt_caps.erl
@ -71,8 +71,9 @@
                       }).

 -spec(check_pub(emqx_types:zone(),
-                #{qos => emqx_types:qos(),
-                  retain => boolean()})
+                #{qos := emqx_types:qos(),
+                  retain := boolean(),
+                  topic := emqx_topic:topic()})
      -> ok_or_error(emqx_types:reason_code())).
 check_pub(Zone, Flags) when is_map(Flags) ->
    do_check_pub(case maps:take(topic, Flags) of
--- a/src/emqx_mqtt_props.erl
+++ b/src/emqx_mqtt_props.erl
@ -128,24 +128,21 @@ name(16#29) -> 'Subscription-Identifier-Available';
 name(16#2A) -> 'Shared-Subscription-Available';
 name(Id)    -> error({unsupported_property, Id}).

-spec(filter(emqx_types:packet_type(), emqx_types:properties()|list())
+-spec(filter(emqx_types:packet_type(), emqx_types:properties())
      -> emqx_types:properties()).
-filter(PacketType, Props) when is_map(Props) ->
-    maps:from_list(filter(PacketType, maps:to_list(Props)));
-
-filter(PacketType, Props) when ?CONNECT =< PacketType,
-                               PacketType =< ?AUTH,
-                               is_list(Props) ->
-    Filter = fun(Name) ->
-                 case maps:find(id(Name), ?PROPS_TABLE) of
-                     {ok, {Name, _Type, 'ALL'}} ->
-                         true;
-                     {ok, {Name, _Type, AllowedTypes}} ->
-                         lists:member(PacketType, AllowedTypes);
-                     error -> false
-                 end
-             end,
-    [Prop || Prop = {Name, _} <- Props, Filter(Name)].
+filter(PacketType, Props) when is_map(Props),
+                               PacketType >= ?CONNECT,
+                               PacketType =< ?AUTH ->
+    F = fun(Name, _) ->
+            case maps:find(id(Name), ?PROPS_TABLE) of
+                {ok, {Name, _Type, 'ALL'}} ->
+                    true;
+                {ok, {Name, _Type, AllowedTypes}} ->
+                    lists:member(PacketType, AllowedTypes);
+                error -> false
+            end
+        end,
+    maps:filter(F, Props).

 -spec(validate(emqx_types:properties()) -> ok).
 validate(Props) when is_map(Props) ->
--- a/src/emqx_mqueue.erl
+++ b/src/emqx_mqueue.erl
@ -101,7 +101,7 @@
          q          = ?PQUEUE:new()      :: pq()
         }).

-opaque(mqueue() :: #mqueue{}).
+-type(mqueue() :: #mqueue{}).

 -spec(init(options()) -> mqueue()).
 init(Opts = #{max_len := MaxLen0, store_qos0 := QoS_0}) ->
--- a/src/emqx_os_mon.erl
+++ b/src/emqx_os_mon.erl
@ -144,9 +144,6 @@ handle_info({timeout, Timer, check}, State = #{timer := Timer,
    NState =
    case emqx_vm:cpu_util() of %% TODO: should be improved?
        0 -> State#{timer := undefined};
-        {error, Reason} ->
-            ?LOG(error, "Failed to get cpu utilization: ~p", [Reason]),
-            ensure_check_timer(State);
        Busy when Busy / 100 >= CPUHighWatermark ->
            alarm_handler:set_alarm({cpu_high_watermark, Busy}),
            ensure_check_timer(State#{is_cpu_alarm_set := true});
--- a/src/emqx_packet.erl
+++ b/src/emqx_packet.erl
@ -373,34 +373,26 @@ validate_topic_filters(TopicFilters) ->
              emqx_topic:validate(TopicFilter)
      end, TopicFilters).

-spec(to_message(emqx_types:clientinfo(), emqx_ypes:packet()) -> emqx_types:message()).
-to_message(ClientInfo, Packet) ->
-    to_message(ClientInfo, #{}, Packet).
+-spec(to_message(emqx_types:packet(), emqx_types:clientid()) -> emqx_types:message()).
+to_message(Packet, ClientId) ->
+    to_message(Packet, ClientId, #{}).

 %% @doc Transform Publish Packet to Message.
-spec(to_message(emqx_types:clientinfo(), map(), emqx_ypes:packet())
-      -> emqx_types:message()).
-to_message(#{protocol := Protocol,
-             clientid := ClientId,
-             username := Username,
-             peerhost := PeerHost
-            }, Headers,
-           #mqtt_packet{header   = #mqtt_packet_header{type   = ?PUBLISH,
-                                                       retain = Retain,
-                                                       qos    = QoS,
-                                                       dup    = Dup
-                                                      },
-                        variable = #mqtt_packet_publish{topic_name = Topic,
-                                                        properties = Props
-                                                       },
-                        payload  = Payload
-                       }) ->
+-spec(to_message(emqx_types:packet(), emqx_types:clientid(), map()) -> emqx_types:message()).
+to_message(#mqtt_packet{
+                header = #mqtt_packet_header{
+                            type   = ?PUBLISH,
+                            retain = Retain,
+                            qos    = QoS,
+                            dup    = Dup},
+                variable = #mqtt_packet_publish{
+                                topic_name = Topic,
+                                properties = Props},
+                payload = Payload
+            }, ClientId, Headers) ->
    Msg = emqx_message:make(ClientId, QoS, Topic, Payload),
-    Headers1 = merge_props(Headers#{protocol => Protocol,
-                                    username => Username,
-                                    peerhost => PeerHost
-                                   }, Props),
-    Msg#message{flags = #{dup => Dup, retain => Retain}, headers = Headers1}.
+    Msg#message{flags = #{dup => Dup, retain => Retain},
+                headers = Headers#{properties => Props}}.

 -spec(will_msg(#mqtt_packet_connect{}) -> emqx_types:message()).
 will_msg(#mqtt_packet_connect{will_flag = false}) ->
@ -413,13 +405,8 @@ will_msg(#mqtt_packet_connect{clientid     = ClientId,
                              will_props   = Props,
                              will_payload = Payload}) ->
    Msg = emqx_message:make(ClientId, QoS, Topic, Payload),
-    Headers = merge_props(#{username => Username}, Props),
-    Msg#message{flags = #{dup => false, retain => Retain}, headers = Headers}.
-
-merge_props(Headers, undefined) ->
-    Headers;
-merge_props(Headers, Props) ->
-    maps:merge(Headers, Props).
+    Msg#message{flags = #{dup => false, retain => Retain},
+                headers = #{username => Username, properties => Props}}.

 %% @doc Format packet
 -spec(format(emqx_types:packet()) -> iolist()).
@ -497,10 +484,11 @@ format_variable(#mqtt_packet_suback{packet_id = PacketId,
 format_variable(#mqtt_packet_unsuback{packet_id = PacketId}) ->
    io_lib:format("PacketId=~p", [PacketId]);

-format_variable(PacketId) when is_integer(PacketId) ->
-    io_lib:format("PacketId=~p", [PacketId]);
+format_variable(#mqtt_packet_auth{reason_code = ReasonCode}) ->
+    io_lib:format("ReasonCode=~p", [ReasonCode]);

-format_variable(undefined) -> undefined.
+format_variable(PacketId) when is_integer(PacketId) ->
+    io_lib:format("PacketId=~p", [PacketId]).

 format_password(undefined) -> undefined;
 format_password(_Password) -> '******'.
--- a/src/emqx_plugins.erl
+++ b/src/emqx_plugins.erl
@ -38,6 +38,11 @@
 -compile(export_all).
 -compile(nowarn_export_all).
 -endif.
+
+-dialyzer({no_match, [ plugin_loaded/2
+                     , plugin_unloaded/2
+                     ]}).
+
 %%--------------------------------------------------------------------
 %% APIs
 %%--------------------------------------------------------------------
--- a/src/emqx_pool_sup.erl
+++ b/src/emqx_pool_sup.erl
@ -18,6 +18,8 @@

 -behaviour(supervisor).

+-include("types.hrl").
+
 -export([spec/1, spec/2]).

 -export([ start_link/0
@ -46,12 +48,12 @@ spec(ChildId, Args) ->
 start_link() ->
    start_link(?POOL, random, {?POOL, start_link, []}).

-spec(start_link(atom() | tuple(), atom(), mfa())
+-spec(start_link(atom() | tuple(), atom(), mfargs())
      -> {ok, pid()} | {error, term()}).
 start_link(Pool, Type, MFA) ->
    start_link(Pool, Type, emqx_vm:schedulers(), MFA).

-spec(start_link(atom() | tuple(), atom(), pos_integer(), mfa())
+-spec(start_link(atom() | tuple(), atom(), pos_integer(), mfargs())
      -> {ok, pid()} | {error, term()}).
 start_link(Pool, Type, Size, MFA) ->
    supervisor:start_link(?MODULE, [Pool, Type, Size, MFA]).
--- a/src/emqx_router_helper.erl
+++ b/src/emqx_router_helper.erl
@ -53,6 +53,8 @@
 -define(ROUTING_NODE, emqx_routing_node).
 -define(LOCK, {?MODULE, cleanup_routes}).

+-dialyzer({nowarn_function, [cleanup_routes/1]}).
+
 %%--------------------------------------------------------------------
 %% Mnesia bootstrap
 %%--------------------------------------------------------------------
--- a/src/emqx_session.erl
+++ b/src/emqx_session.erl
@ -63,7 +63,7 @@
        ]).

 -export([ subscribe/4
-        , unsubscribe/3
+        , unsubscribe/4
        ]).

 -export([ publish/3
@ -123,7 +123,7 @@
          created_at :: pos_integer()
         }).

-opaque(session() :: #session{}).
+-type(session() :: #session{}).

 -type(publish() :: {maybe(emqx_types:packet_id()), emqx_types:message()}).

@ -152,6 +152,7 @@

 -define(DEFAULT_BATCH_N, 1000).

+
 %%--------------------------------------------------------------------
 %% Init a Session
 %%--------------------------------------------------------------------
@ -261,13 +262,13 @@ is_subscriptions_full(#session{subscriptions = Subs,
 %% Client -> Broker: UNSUBSCRIBE
 %%--------------------------------------------------------------------

-spec(unsubscribe(emqx_types:clientinfo(), emqx_types:topic(), session())
+-spec(unsubscribe(emqx_types:clientinfo(), emqx_types:topic(), emqx_types:subopts(), session())
      -> {ok, session()} | {error, emqx_types:reason_code()}).
-unsubscribe(ClientInfo, TopicFilter, Session = #session{subscriptions = Subs}) ->
+unsubscribe(ClientInfo, TopicFilter, UnSubOpts, Session = #session{subscriptions = Subs}) ->
    case maps:find(TopicFilter, Subs) of
        {ok, SubOpts} ->
            ok = emqx_broker:unsubscribe(TopicFilter),
-            ok = emqx_hooks:run('session.unsubscribed', [ClientInfo, TopicFilter, SubOpts]),
+            ok = emqx_hooks:run('session.unsubscribed', [ClientInfo, TopicFilter, maps:merge(SubOpts, UnSubOpts)]),
            {ok, Session#session{subscriptions = maps:remove(TopicFilter, Subs)}};
        error ->
            {error, ?RC_NO_SUBSCRIPTION_EXISTED}
@ -523,7 +524,8 @@ enrich_subopts([{rap, 0}|Opts], Msg = #message{headers = #{retained := true}}, S
 enrich_subopts([{rap, 0}|Opts], Msg, Session) ->
    enrich_subopts(Opts, emqx_message:set_flag(retain, false, Msg), Session);
 enrich_subopts([{subid, SubId}|Opts], Msg, Session) ->
-    Msg1 = emqx_message:set_header('Subscription-Identifier', SubId, Msg),
+    Props = emqx_message:get_header(properties, Msg, #{}),
+    Msg1 = emqx_message:set_header(properties, Props#{'Subscription-Identifier' => SubId}, Msg),
    enrich_subopts(Opts, Msg1, Session).

 %%--------------------------------------------------------------------
@ -615,19 +617,16 @@ resume(ClientInfo = #{clientid := ClientId}, Session = #session{subscriptions =

 -spec(replay(session()) -> {ok, replies(), session()}).
 replay(Session = #session{inflight = Inflight}) ->
-    Pubs = replay(Inflight),
+    Pubs = lists:map(fun({PacketId, {pubrel, _Ts}}) ->
+                             {pubrel, PacketId};
+                        ({PacketId, {Msg, _Ts}}) ->
+                             {PacketId, emqx_message:set_flag(dup, true, Msg)}
+                     end, emqx_inflight:to_list(Inflight)),
    case dequeue(Session) of
        {ok, NSession} -> {ok, Pubs, NSession};
        {ok, More, NSession} ->
            {ok, lists:append(Pubs, More), NSession}
-    end;
-
-replay(Inflight) ->
-    lists:map(fun({PacketId, {pubrel, _Ts}}) ->
-                      {pubrel, PacketId};
-                 ({PacketId, {Msg, _Ts}}) ->
-                      {PacketId, emqx_message:set_flag(dup, true, Msg)}
-              end, emqx_inflight:to_list(Inflight)).
+    end.

 -spec(terminate(emqx_types:clientinfo(), Reason :: term(), session()) -> ok).
 terminate(ClientInfo, discarded, Session) ->
--- a/src/emqx_stats.erl
+++ b/src/emqx_stats.erl
@ -58,7 +58,7 @@
 -record(update, {name, countdown, interval, func}).

 -record(state, {
-          timer   :: reference(),
+          timer   :: maybe(reference()),
          updates :: [#update{}],
          tick_ms :: timeout()
         }).
@ -159,7 +159,7 @@ setstat(Stat, Val) when is_integer(Val) ->

 %% @doc Set stats with max value.
 -spec(setstat(Stat :: atom(), MaxStat :: atom(),
-              Val :: pos_integer()) -> boolean()).
+              Val :: pos_integer()) -> ok).
 setstat(Stat, MaxStat, Val) when is_integer(Val) ->
    cast({setstat, Stat, MaxStat, Val}).

--- a/src/emqx_sys.erl
+++ b/src/emqx_sys.erl
@ -19,6 +19,7 @@
 -behaviour(gen_server).

 -include("emqx.hrl").
+-include("types.hrl").
 -include("logger.hrl").

 -logger_header("[SYS]").
@ -53,20 +54,12 @@
 -import(emqx_topic, [systop/1]).
 -import(emqx_misc, [start_timer/2]).

-type(timeref() :: reference()).
-
-type(tickeref() :: reference()).
-
-type(version() :: string()).
-
-type(sysdescr() :: string()).
-
 -record(state,
        { start_time :: erlang:timestamp()
-        , heartbeat  :: timeref()
-        , ticker     :: tickeref()
-        , version    :: version()
-        , sysdescr   :: sysdescr()
+        , heartbeat  :: maybe(reference())
+        , ticker     :: maybe(reference())
+        , version    :: binary()
+        , sysdescr   :: binary()
        }).

 -define(APP, emqx).
--- a/src/emqx_sys_mon.erl
+++ b/src/emqx_sys_mon.erl
@ -18,8 +18,8 @@

 -behavior(gen_server).

-include("logger.hrl").
 -include("types.hrl").
+-include("logger.hrl").

 -logger_header("[SYSMON]").

@ -171,9 +171,11 @@ handle_partition_event({partition, {healed, _Node}}) ->

 suppress(Key, SuccFun, State = #{events := Events}) ->
    case lists:member(Key, Events) of
-        true  -> {noreply, State};
-        false -> SuccFun(),
-                 {noreply, State#{events := [Key|Events]}}
+        true ->
+            {noreply, State};
+        false ->
+            SuccFun(),
+            {noreply, State#{events := [Key|Events]}}
    end.

 procinfo(Pid) ->
--- a/src/emqx_topic.erl
+++ b/src/emqx_topic.erl
@ -21,7 +21,6 @@
        , validate/1
        , validate/2
        , levels/1
-        , triples/1
        , tokens/1
        , words/1
        , wildcard/1
@ -36,14 +35,12 @@
 -export_type([ group/0
             , topic/0
             , word/0
-             , triple/0
             ]).

 -type(group() :: binary()).
 -type(topic() :: binary()).
 -type(word() :: '' | '+' | '#' | binary()).
 -type(words() :: list(word())).
-opaque(triple() :: {root | binary(), word(), binary()}).

 -define(MAX_TOPIC_LEN, 4096).

@ -129,32 +126,15 @@ validate3(<<C/utf8, _Rest/binary>>) when C == $#; C == $+; C == 0 ->
 validate3(<<_/utf8, Rest/binary>>) ->
    validate3(Rest).

-%% @doc Topic to triples.
-spec(triples(topic()) -> list(triple())).
-triples(Topic) when is_binary(Topic) ->
-    triples(words(Topic), root, []).
-
-triples([], _Parent, Acc) ->
-    lists:reverse(Acc);
-triples([W|Words], Parent, Acc) ->
-    Node = join(Parent, W),
-    triples(Words, Node, [{Parent, W, Node}|Acc]).
-
-join(root, W) ->
-    bin(W);
-join(Parent, W) ->
-    <<(bin(Parent))/binary, $/, (bin(W))/binary>>.
-
 %% @doc Prepend a topic prefix.
 %% Ensured to have only one / between prefix and suffix.
-prepend(root, W) -> bin(W);
 prepend(undefined, W) -> bin(W);
 prepend(<<>>, W) -> bin(W);
 prepend(Parent0, W) ->
    Parent = bin(Parent0),
    case binary:last(Parent) of
        $/ -> <<Parent/binary, (bin(W))/binary>>;
-        _ -> join(Parent, W)
+        _ -> <<Parent/binary, $/, (bin(W))/binary>>
    end.

 bin('')  -> <<>>;
@ -184,6 +164,7 @@ word(<<"#">>) -> '#';
 word(Bin)     -> Bin.

 %% @doc '$SYS' Topic.
+-spec(systop(atom()|string()|binary()) -> topic()).
 systop(Name) when is_atom(Name); is_list(Name) ->
    iolist_to_binary(lists:concat(["$SYS/brokers/", node(), "/", Name]));
 systop(Name) when is_binary(Name) ->
--- a/src/emqx_tracer.erl
+++ b/src/emqx_tracer.erl
@ -57,6 +57,8 @@
        L =:= info orelse
        L =:= debug).

+-dialyzer({nowarn_function, [install_trace_handler/3]}).
+
 %%------------------------------------------------------------------------------
 %% APIs
 %%------------------------------------------------------------------------------
@ -68,7 +70,7 @@ trace(publish, #message{from = From, topic = Topic, payload = Payload})
    emqx_logger:info(#{topic => Topic, mfa => {?MODULE, ?FUNCTION_NAME, ?FUNCTION_ARITY} }, "PUBLISH to ~s: ~0p", [Topic, Payload]).

 %% @doc Start to trace clientid or topic.
-spec(start_trace(trace_who(), logger:level(), string()) -> ok | {error, term()}).
+-spec(start_trace(trace_who(), logger:level() | all, string()) -> ok | {error, term()}).
 start_trace(Who, all, LogFile) ->
    start_trace(Who, debug, LogFile);
 start_trace(Who, Level, LogFile) ->
--- a/src/emqx_trie.erl
+++ b/src/emqx_trie.erl
@ -33,6 +33,13 @@

 -export([empty/0]).

+-ifdef(TEST).
+-compile(export_all).
+-compile(nowarn_export_all).
+-endif.
+
+-type(triple() :: {root | binary(), emqx_topic:word(), binary()}).
+
 %% Mnesia tables
 -define(TRIE_TAB, emqx_trie).
 -define(TRIE_NODE_TAB, emqx_trie_node).
@ -80,7 +87,7 @@ insert(Topic) when is_binary(Topic) ->
            write_trie_node(TrieNode#trie_node{topic = Topic});
        [] ->
            %% Add trie path
-            ok = lists:foreach(fun add_path/1, emqx_topic:triples(Topic)),
+            ok = lists:foreach(fun add_path/1, triples(Topic)),
            %% Add last node
            write_trie_node(#trie_node{node_id = Topic, topic = Topic})
    end.
@ -102,7 +109,7 @@ delete(Topic) when is_binary(Topic) ->
    case mnesia:wread({?TRIE_NODE_TAB, Topic}) of
        [#trie_node{edge_count = 0}] ->
            ok = mnesia:delete({?TRIE_NODE_TAB, Topic}),
-            delete_path(lists:reverse(emqx_topic:triples(Topic)));
+            delete_path(lists:reverse(triples(Topic)));
        [TrieNode] ->
            write_trie_node(TrieNode#trie_node{topic = undefined});
        [] -> ok
@ -117,6 +124,22 @@ empty() ->
 %% Internal functions
 %%--------------------------------------------------------------------

+%% @doc Topic to triples.
+-spec(triples(emqx_topic:topic()) -> list(triple())).
+triples(Topic) when is_binary(Topic) ->
+    triples(emqx_topic:words(Topic), root, []).
+
+triples([], _Parent, Acc) ->
+    lists:reverse(Acc);
+triples([W|Words], Parent, Acc) ->
+    Node = join(Parent, W),
+    triples(Words, Node, [{Parent, W, Node}|Acc]).
+
+join(root, W) ->
+    emqx_topic:join([W]);
+join(Parent, W) ->
+    emqx_topic:join([Parent, W]).
+
 %% @private
 %% @doc Add a path to the trie.
 add_path({Node, Word, Child}) ->
--- a/src/emqx_types.erl
+++ b/src/emqx_types.erl
@ -63,6 +63,9 @@

 -export_type([ payload/0
             , message/0
+             , flag/0
+             , flags/0
+             , headers/0
             ]).

 -export_type([ deliver/0
@ -133,7 +136,7 @@
                        is_bridge    := boolean(),
                        is_superuser := boolean(),
                        mountpoint   := maybe(binary()),
-                        ws_cookie    := maybe(list()),
+                        ws_cookie    => maybe(list()),
                        password     => maybe(binary()),
                        auth_result  => auth_result(),
                        anonymous    => boolean(),
@ -179,6 +182,9 @@
 -type(subscriber() :: {pid(), subid()}).
 -type(payload() :: binary() | iodata()).
 -type(message() :: #message{}).
+-type(flag() :: atom()).
+-type(flags() :: #{flag() := boolean()}).
+-type(headers() :: map()).
 -type(banned() :: #banned{}).
 -type(deliver() :: {deliver, topic(), message()}).
 -type(delivery() :: #delivery{}).
@ -195,7 +201,7 @@
 -type(caps() :: emqx_mqtt_caps:caps()).
 -type(attrs() :: #{atom() => term()}).
 -type(infos() :: #{atom() => term()}).
-type(stats() :: #{atom() => non_neg_integer()|stats()}).
+-type(stats() :: [{atom(), term()}]).

 -type(oom_policy() :: #{message_queue_len => non_neg_integer(),
                        max_heap_size => non_neg_integer()
--- a/src/emqx_vm.erl
+++ b/src/emqx_vm.erl
@ -48,13 +48,13 @@
        , get_port_info/1
        ]).

+-export([cpu_util/0]).
+
 -ifdef(TEST).
 -compile(export_all).
 -compile(nowarn_export_all).
 -endif.

-export([cpu_util/0]).
-
 -define(UTIL_ALLOCATORS, [temp_alloc,
                          eheap_alloc,
                          binary_alloc,
@ -408,9 +408,6 @@ port_info(PortTerm, specific) ->
                    []
            end,
    {specific, Props};
-port_info(PortTerm, Keys) when is_list(Keys) ->
-    Port = transform_port(PortTerm),
-    [erlang:port_info(Port, Key) || Key <- Keys];
 port_info(PortTerm, Key) when is_atom(Key) ->
    Port = transform_port(PortTerm),
    erlang:port_info(Port, Key).
--- a/src/emqx_ws_connection.erl
+++ b/src/emqx_ws_connection.erl
@ -63,7 +63,7 @@
          %% Simulate the active_n opt
          active_n :: pos_integer(),
          %% Limiter
-          limiter :: emqx_limiter:limiter(),
+          limiter :: maybe(emqx_limiter:limiter()),
          %% Limit Timer
          limit_timer :: maybe(reference()),
          %% Parse State
@ -81,7 +81,7 @@
          %% Idle Timeout
          idle_timeout :: timeout(),
          %% Idle Timer
-          idle_timer :: reference()
+          idle_timer :: maybe(reference())
        }).

 -type(state() :: #state{}).
@ -95,6 +95,9 @@

 -define(ENABLED(X), (X =/= undefined)).

+-dialyzer({no_match, [info/2]}).
+-dialyzer({nowarn_function, [websocket_init/1]}).
+
 %%--------------------------------------------------------------------
 %% Info, Stats
 %%--------------------------------------------------------------------
--- a/src/emqx_zone.erl
+++ b/src/emqx_zone.erl
@ -45,6 +45,7 @@
          , session_expiry_interval/1
          , force_gc_policy/1
          , force_shutdown_policy/1
+          , response_information/1
          , get_env/2
          , get_env/3
          ]}).
@ -72,6 +73,7 @@
        , session_expiry_interval/1
        , force_gc_policy/1
        , force_shutdown_policy/1
+        , response_information/1
        ]).

 -export([ init_gc_state/1
@ -180,7 +182,7 @@ enable_flapping_detect(Zone) ->
 ignore_loop_deliver(Zone) ->
    get_env(Zone, ignore_loop_deliver, false).

-spec(server_keepalive(zone()) -> pos_integer()).
+-spec(server_keepalive(zone()) -> maybe(pos_integer())).
 server_keepalive(Zone) ->
    get_env(Zone, server_keepalive).

@ -204,6 +206,10 @@ force_gc_policy(Zone) ->
 force_shutdown_policy(Zone) ->
    get_env(Zone, force_shutdown_policy).

+-spec(response_information(zone()) -> string()).
+response_information(Zone) ->
+    get_env(Zone, response_information).
+
 %%--------------------------------------------------------------------
 %% APIs
 %%--------------------------------------------------------------------
--- a/test/emqx_SUITE.erl
+++ b/test/emqx_SUITE.erl
@ -77,7 +77,10 @@ t_emqx_pubsub_api(_) ->
    ?assertEqual([self()], emqx:subscribers(Topic)),
    ?assertEqual([self()], emqx:subscribers(Topic1)),
    ?assertEqual([self()], emqx:subscribers(Topic2)),
-    ?assertEqual([{Topic,#{qos => 0,subid => ClientId}}, {Topic1,#{qos => 1,subid => ClientId}}, {Topic2,#{qos => 2,subid => ClientId}}], emqx:subscriptions(self())),
+
+    ?assertEqual([{Topic,  #{nl => 0, qos => 0, rap => 0, rh => 0, subid => ClientId}},
+                  {Topic1, #{nl => 0, qos => 1, rap => 0, rh => 0, subid => ClientId}},
+                  {Topic2, #{nl => 0, qos => 2, rap => 0, rh => 0, subid => ClientId}}], emqx:subscriptions(self())),
    ?assertEqual(true, emqx:subscribed(self(), Topic)),
    ?assertEqual(true, emqx:subscribed(ClientId, Topic)),
    ?assertEqual(true, emqx:subscribed(self(), Topic1)),
--- a/test/emqx_broker_SUITE.erl
+++ b/test/emqx_broker_SUITE.erl
@ -59,12 +59,18 @@ t_subopts(_) ->
    ?assertEqual(undefined, emqx_broker:get_subopts(<<"clientid">>, <<"topic">>)),
    emqx_broker:subscribe(<<"topic">>, <<"clientid">>, #{qos => 1}),
    timer:sleep(200),
-    ?assertEqual(#{qos => 1, subid => <<"clientid">>}, emqx_broker:get_subopts(self(), <<"topic">>)),
-    ?assertEqual(#{qos => 1, subid => <<"clientid">>}, emqx_broker:get_subopts(<<"clientid">>,<<"topic">>)),
+    ?assertEqual(#{nl => 0, qos => 1, rap => 0, rh => 0, subid => <<"clientid">>},
+                 emqx_broker:get_subopts(self(), <<"topic">>)),
+    ?assertEqual(#{nl => 0, qos => 1, rap => 0, rh => 0, subid => <<"clientid">>},
+                 emqx_broker:get_subopts(<<"clientid">>,<<"topic">>)),
+
    emqx_broker:subscribe(<<"topic">>, <<"clientid">>, #{qos => 2}),
-    ?assertEqual(#{qos => 2, subid => <<"clientid">>}, emqx_broker:get_subopts(self(), <<"topic">>)),
-    ?assertEqual(true, emqx_broker:set_subopts(<<"topic">>, #{qos => 2})),
-    ?assertEqual(#{qos => 2, subid => <<"clientid">>}, emqx_broker:get_subopts(self(), <<"topic">>)),
+    ?assertEqual(#{nl => 0, qos => 2, rap => 0, rh => 0, subid => <<"clientid">>},
+                 emqx_broker:get_subopts(self(), <<"topic">>)),
+
+    ?assertEqual(true, emqx_broker:set_subopts(<<"topic">>, #{qos => 0})),
+    ?assertEqual(#{nl => 0, qos => 0, rap => 0, rh => 0, subid => <<"clientid">>},
+                 emqx_broker:get_subopts(self(), <<"topic">>)),
    emqx_broker:unsubscribe(<<"topic">>).

 t_topics(_) ->
@ -91,9 +97,9 @@ t_subscribers(_) ->
 t_subscriptions(_) ->
    emqx_broker:subscribe(<<"topic">>, <<"clientid">>, #{qos => 1}),
    ok = timer:sleep(100),
-    ?assertEqual(#{qos => 1, subid => <<"clientid">>},
+    ?assertEqual(#{nl => 0, qos => 1, rap => 0, rh => 0, subid => <<"clientid">>},
                 proplists:get_value(<<"topic">>, emqx_broker:subscriptions(self()))),
-    ?assertEqual(#{qos => 1, subid => <<"clientid">>},
+    ?assertEqual(#{nl => 0, qos => 1, rap => 0, rh => 0, subid => <<"clientid">>},
                 proplists:get_value(<<"topic">>, emqx_broker:subscriptions(<<"clientid">>))),
    emqx_broker:unsubscribe(<<"topic">>).

--- a/test/emqx_channel_SUITE.erl
+++ b/test/emqx_channel_SUITE.erl
@ -58,7 +58,8 @@ end_per_suite(_Config) ->
                 emqx_session,
                 emqx_broker,
                 emqx_hooks,
-                 emqx_cm
+                 emqx_cm,
+                 emqx_zone
                ]).

 init_per_testcase(_TestCase, Config) ->
@ -152,6 +153,8 @@ t_handle_in_re_auth(_) ->
                },
    {ok, [{outgoing, ?DISCONNECT_PACKET(?RC_BAD_AUTHENTICATION_METHOD)}, {close, bad_authentication_method}], _} =
        emqx_channel:handle_in(?AUTH_PACKET(?RC_RE_AUTHENTICATE,Properties), channel()),
+    {ok, [{outgoing, ?DISCONNECT_PACKET(?RC_BAD_AUTHENTICATION_METHOD)}, {close, bad_authentication_method}], _} =
+        emqx_channel:handle_in(?AUTH_PACKET(?RC_RE_AUTHENTICATE,Properties), channel(#{conninfo => #{proto_ver => ?MQTT_PROTO_V5, conn_props => undefined}})),
    {ok, [{outgoing, ?DISCONNECT_PACKET(?RC_NOT_AUTHORIZED)}, {close, not_authorized}], _} =
        emqx_channel:handle_in(?AUTH_PACKET(?RC_RE_AUTHENTICATE,Properties), channel(#{conninfo => #{proto_ver => ?MQTT_PROTO_V5, conn_props => Properties}})).

@ -279,7 +282,7 @@ t_handle_in_subscribe(_) ->

 t_handle_in_unsubscribe(_) ->
    ok = meck:expect(emqx_session, unsubscribe,
-                     fun(_, _, Session) ->
+                     fun(_, _, _, Session) ->
                             {ok, Session}
                     end),
    Channel = channel(#{conn_state => connected}),
@ -345,12 +348,12 @@ t_process_publish_qos1(_) ->
 t_process_subscribe(_) ->
    ok = meck:expect(emqx_session, subscribe, fun(_, _, _, Session) -> {ok, Session} end),
    TopicFilters = [{<<"+">>, ?DEFAULT_SUBOPTS}],
-    {[?RC_SUCCESS], _Channel} = emqx_channel:process_subscribe(TopicFilters, channel()).
+    {[?RC_SUCCESS], _Channel} = emqx_channel:process_subscribe(TopicFilters, #{}, channel()).

 t_process_unsubscribe(_) ->
-    ok = meck:expect(emqx_session, unsubscribe, fun(_, _, Session) -> {ok, Session} end),
+    ok = meck:expect(emqx_session, unsubscribe, fun(_, _, _, Session) -> {ok, Session} end),
    TopicFilters = [{<<"+">>, ?DEFAULT_SUBOPTS}],
-    {[?RC_SUCCESS], _Channel} = emqx_channel:process_unsubscribe(TopicFilters, channel()).
+    {[?RC_SUCCESS], _Channel} = emqx_channel:process_unsubscribe(TopicFilters, #{}, channel()).

 %%--------------------------------------------------------------------
 %% Test cases for handle_deliver
@ -392,6 +395,27 @@ t_handle_out_connack_sucess(_) ->
        emqx_channel:handle_out(connack, {?RC_SUCCESS, 0, #{}}, channel()),
    ?assertEqual(connected, emqx_channel:info(conn_state, Channel)).

+t_handle_out_connack_response_information(_) ->
+    ok = meck:expect(emqx_cm, open_session,
+                     fun(true, _ClientInfo, _ConnInfo) ->
+                             {ok, #{session => session(), present => false}}
+                     end),
+    ok = meck:expect(emqx_zone, response_information, fun(_) -> test end),
+    IdleChannel = channel(#{conn_state => idle}),
+    {ok, [{event, connected}, {connack, ?CONNACK_PACKET(?RC_SUCCESS, 0, #{'Response-Information' := test})}], _} =
+        emqx_channel:handle_in(?CONNECT_PACKET(connpkt(#{'Request-Response-Information' => 1})), IdleChannel).
+
+t_handle_out_connack_not_response_information(_) ->
+    ok = meck:expect(emqx_cm, open_session,
+                     fun(true, _ClientInfo, _ConnInfo) ->
+                             {ok, #{session => session(), present => false}}
+                     end),
+    ok = meck:expect(emqx_zone, response_information, fun(_) -> test end),
+    IdleChannel = channel(#{conn_state => idle}),
+    {ok, [{event, connected}, {connack, ?CONNACK_PACKET(?RC_SUCCESS, 0, AckProps)}], _} =
+        emqx_channel:handle_in(?CONNECT_PACKET(connpkt(#{'Request-Response-Information' => 0})), IdleChannel),
+    ?assertEqual(false, maps:is_key('Response-Information', AckProps)).
+
 t_handle_out_connack_failure(_) ->
    {shutdown, not_authorized, ?CONNACK_PACKET(?RC_NOT_AUTHORIZED), _Chan} =
        emqx_channel:handle_out(connack, ?RC_NOT_AUTHORIZED, channel()).
@ -465,7 +489,7 @@ t_handle_info_subscribe(_) ->
    {ok, _Chan} = emqx_channel:handle_info({subscribe, topic_filters()}, channel()).

 t_handle_info_unsubscribe(_) ->
-    ok = meck:expect(emqx_session, unsubscribe, fun(_, _, Session) -> {ok, Session} end),
+    ok = meck:expect(emqx_session, unsubscribe, fun(_, _, _, Session) -> {ok, Session} end),
    {ok, _Chan} = emqx_channel:handle_info({unsubscribe, topic_filters()}, channel()).

 t_handle_info_sock_closed(_) ->
@ -541,7 +565,7 @@ t_packing_alias(_) ->
    ?assertEqual(#mqtt_packet{variable = #mqtt_packet_publish{topic_name = <<>>, properties = #{'Topic-Alias' => 1}}}, RePacket2),

    {RePacket3, _} = emqx_channel:packing_alias(Packet2, NChannel2),
-    ?assertEqual(#mqtt_packet{variable = #mqtt_packet_publish{topic_name = <<"y">>, properties = undefined}}, RePacket3),
+    ?assertEqual(#mqtt_packet{variable = #mqtt_packet_publish{topic_name = <<"y">>, properties = #{}}}, RePacket3),

    ?assertMatch({#mqtt_packet{variable = #mqtt_packet_publish{topic_name = <<"z">>}}, _},  emqx_channel:packing_alias(#mqtt_packet{variable = #mqtt_packet_publish{topic_name = <<"z">>}}, channel())).

@ -637,14 +661,15 @@ clientinfo(InitProps) ->
 topic_filters() ->
    [{<<"+">>, ?DEFAULT_SUBOPTS}, {<<"#">>, ?DEFAULT_SUBOPTS}].

-connpkt() ->
+connpkt() -> connpkt(#{}).
+connpkt(Props) ->
    #mqtt_packet_connect{
       proto_name  = <<"MQTT">>,
       proto_ver   = ?MQTT_PROTO_V4,
       is_bridge   = false,
       clean_start = true,
       keepalive   = 30,
-       properties  = undefined,
+       properties  = Props,
       clientid    = <<"clientid">>,
       username    = <<"username">>,
       password    = <<"passwd">>
--- a/test/emqx_frame_SUITE.erl
+++ b/test/emqx_frame_SUITE.erl
@ -20,14 +20,10 @@
 -compile(nowarn_export_all).

 -include("emqx_mqtt.hrl").
-include_lib("proper/include/proper.hrl").
 -include_lib("eunit/include/eunit.hrl").
 -include_lib("common_test/include/ct.hrl").
 -include_lib("emqx_ct_helpers/include/emqx_ct.hrl").

-%%-define(PROPTEST(F), ?assert(proper:quickcheck(F()))).
-define(PROPTEST(F), ?assert(proper:quickcheck(F(), [{to_file, user}]))).
-
 all() ->
    [{group, parse},
     {group, connect},
@ -49,8 +45,7 @@ groups() ->
       t_parse_frame_too_large
      ]},
     {connect, [parallel],
-      [t_serialize_parse_connect,
-       t_serialize_parse_v3_connect,
+      [t_serialize_parse_v3_connect,
       t_serialize_parse_v4_connect,
       t_serialize_parse_v5_connect,
       t_serialize_parse_connect_without_clientid,
@ -134,33 +129,6 @@ t_parse_frame_too_large(_) ->
    ?catch_error(frame_too_large, parse_serialize(Packet, #{max_size => 512})),
    ?assertEqual(Packet, parse_serialize(Packet, #{max_size => 2048, version => ?MQTT_PROTO_V4})).

-t_serialize_parse_connect(_) ->
-    ?PROPTEST(prop_serialize_parse_connect).
-
-prop_serialize_parse_connect() ->
-    ?FORALL(Opts = #{version := ProtoVer}, parse_opts(),
-            begin
-                ProtoName = proplists:get_value(ProtoVer, ?PROTOCOL_NAMES),
-                DefaultProps = if ProtoVer == ?MQTT_PROTO_V5 ->
-                                      #{};
-                                  true -> undefined
-                               end,
-                Packet = ?CONNECT_PACKET(#mqtt_packet_connect{
-                                            proto_name   = ProtoName,
-                                            proto_ver    = ProtoVer,
-                                            clientid     = <<"clientId">>,
-                                            will_qos     = ?QOS_1,
-                                            will_flag    = true,
-                                            will_retain  = true,
-                                            will_topic   = <<"will">>,
-                                            will_props   = DefaultProps,
-                                            will_payload = <<"bye">>,
-                                            clean_start  = true,
-                                            properties = DefaultProps
-                                           }),
-                ok == ?assertEqual(Packet, parse_serialize(Packet, Opts))
-            end).
-
 t_serialize_parse_v3_connect(_) ->
    Bin = <<16,37,0,6,77,81,73,115,100,112,3,2,0,60,0,23,109,111,115,
            113,112,117, 98,47,49,48,52,53,49,45,105,77,97,99,46,108,
@ -534,9 +502,6 @@ t_serialize_parse_auth_v5(_) ->
    ?assertEqual(Packet, parse_serialize(Packet, #{version => ?MQTT_PROTO_V5,
                                                   strict_mode => true})).

-parse_opts() ->
-    ?LET(PropList, [{strict_mode, boolean()}, {version, range(4,5)}], maps:from_list(PropList)).
-
 parse_serialize(Packet) ->
    parse_serialize(Packet, #{strict_mode => true}).

--- a/test/emqx_listeners_SUITE.erl
+++ b/test/emqx_listeners_SUITE.erl
@ -48,7 +48,7 @@ t_restart_listeners(_) ->
    ok = emqx_listeners:stop().

 render_config_file() ->
-    Path = local_path(["etc", "emqx.conf"]),
+    Path = local_path(["..", "..", "..", "..", "etc", "emqx.conf"]),
    {ok, Temp} = file:read_file(Path),
    Vars0 = mustache_vars(),
    Vars = [{atom_to_list(N), iolist_to_binary(V)} || {N, V} <- Vars0],
--- a/test/emqx_message_SUITE.erl
+++ b/test/emqx_message_SUITE.erl
@ -86,7 +86,7 @@ t_clean_dup(_) ->
    ?assertNot(emqx_message:get_flag(dup, Msg2)).

 t_get_set_flags(_) ->
-    Msg = #message{id = <<"id">>, qos = ?QOS_1, flags = undefined},
+    Msg = #message{id = <<"id">>, qos = ?QOS_1},
    Msg1 = emqx_message:set_flags(#{retain => true}, Msg),
    ?assertEqual(#{retain => true}, emqx_message:get_flags(Msg1)),
    Msg2 = emqx_message:set_flags(#{dup => true}, Msg1),
@ -109,7 +109,7 @@ t_get_set_flag(_) ->
    Msg6 = emqx_message:set_flags(#{dup => true, retain => true}, Msg5),
    ?assert(emqx_message:get_flag(dup, Msg6)),
    ?assert(emqx_message:get_flag(retain, Msg6)),
-    Msg7 = #message{id = <<"id">>, qos = ?QOS_1, flags = undefined},
+    Msg7 = #message{id = <<"id">>, qos = ?QOS_1},
    Msg8 = emqx_message:set_flag(retain, Msg7),
    Msg9 = emqx_message:set_flag(retain, true, Msg7),
    ?assertEqual(#{retain => true}, emqx_message:get_flags(Msg8)),
@ -135,7 +135,7 @@ t_get_set_header(_) ->
    ?assertEqual(#{b => 2, c => 3}, emqx_message:get_headers(Msg4)).

 t_undefined_headers(_) ->
-    Msg = #message{id = <<"id">>, qos = ?QOS_0, headers = undefined},
+    Msg = #message{id = <<"id">>, qos = ?QOS_0},
    Msg1 = emqx_message:set_headers(#{a => 1, b => 2}, Msg),
    ?assertEqual(1, emqx_message:get_header(a, Msg1)),
    Msg2 = emqx_message:set_header(c, 3, Msg),
@ -144,14 +144,14 @@ t_undefined_headers(_) ->
 t_format(_) ->
    Msg = emqx_message:make(<<"clientid">>, <<"topic">>, <<"payload">>),
    io:format("~s~n", [emqx_message:format(Msg)]),
-    Msg1 = emqx_message:set_header('Subscription-Identifier', 1,
+    Msg1 = emqx_message:set_header(properties, #{'Subscription-Identifier' => 1},
                                   emqx_message:set_flag(dup, Msg)),
    io:format("~s~n", [emqx_message:format(Msg1)]).

 t_is_expired(_) ->
    Msg = emqx_message:make(<<"clientid">>, <<"topic">>, <<"payload">>),
    ?assertNot(emqx_message:is_expired(Msg)),
-    Msg1 = emqx_message:set_headers(#{'Message-Expiry-Interval' => 1}, Msg),
+    Msg1 = emqx_message:set_headers(#{properties => #{'Message-Expiry-Interval' => 1}}, Msg),
    timer:sleep(500),
    ?assertNot(emqx_message:is_expired(Msg1)),
    timer:sleep(600),
@ -159,7 +159,8 @@ t_is_expired(_) ->
    timer:sleep(1000),
    Msg = emqx_message:update_expiry(Msg),
    Msg2 = emqx_message:update_expiry(Msg1),
-    ?assertEqual(1, emqx_message:get_header('Message-Expiry-Interval', Msg2)).
+    Props = emqx_message:get_header(properties, Msg2),
+    ?assertEqual(1, maps:get('Message-Expiry-Interval', Props)).

 % t_to_list(_) ->
 %     error('TODO').
@ -172,7 +173,7 @@ t_to_packet(_) ->
                                                     },
                       variable = #mqtt_packet_publish{topic_name = <<"topic">>,
                                                       packet_id  = 10,
-                                                       properties = undefined
+                                                       properties = #{}
                                                      },
                       payload  = <<"payload">>
                      },
@ -193,7 +194,7 @@ t_to_packet_with_props(_) ->
                       payload  = <<"payload">>
                      },
    Msg = emqx_message:make(<<"clientid">>, ?QOS_0, <<"topic">>, <<"payload">>),
-    Msg1 = emqx_message:set_header('Subscription-Identifier', 1, Msg),
+    Msg1 = emqx_message:set_header(properties, #{'Subscription-Identifier' => 1}, Msg),
    ?assertEqual(Pkt, emqx_message:to_packet(10, Msg1)).

 t_to_map(_) ->
@ -201,8 +202,8 @@ t_to_map(_) ->
    List = [{id, emqx_message:id(Msg)},
            {qos, ?QOS_1},
            {from, <<"clientid">>},
-            {flags, undefined},
-            {headers, undefined},
+            {flags, #{}},
+            {headers, #{}},
            {topic, <<"topic">>},
            {payload, <<"payload">>},
            {timestamp, emqx_message:timestamp(Msg)}],
--- a/test/emqx_packet_SUITE.erl
+++ b/test/emqx_packet_SUITE.erl
@ -85,7 +85,6 @@ t_connect_info(_) ->
                                   will_retain = true,
                                   will_qos = ?QOS_2,
                                   will_topic = <<"topic">>,
-                                   will_props = undefined,
                                   will_payload = <<"payload">>
                                  },
    ?assertEqual(<<"MQTT">>, emqx_packet:info(proto_name, ConnPkt)),
@ -96,9 +95,9 @@ t_connect_info(_) ->
    ?assertEqual(?QOS_2, emqx_packet:info(will_qos, ConnPkt)),
    ?assertEqual(true, emqx_packet:info(will_retain, ConnPkt)),
    ?assertEqual(0, emqx_packet:info(keepalive, ConnPkt)),
-    ?assertEqual(undefined, emqx_packet:info(properties, ConnPkt)),
+    ?assertEqual(#{}, emqx_packet:info(properties, ConnPkt)),
    ?assertEqual(<<"clientid">>, emqx_packet:info(clientid, ConnPkt)),
-    ?assertEqual(undefined, emqx_packet:info(will_props, ConnPkt)),
+    ?assertEqual(#{}, emqx_packet:info(will_props, ConnPkt)),
    ?assertEqual(<<"topic">>, emqx_packet:info(will_topic, ConnPkt)),
    ?assertEqual(<<"payload">>, emqx_packet:info(will_payload, ConnPkt)),
    ?assertEqual(<<"username">>, emqx_packet:info(username, ConnPkt)),
@ -108,54 +107,54 @@ t_connack_info(_) ->
    AckPkt = #mqtt_packet_connack{ack_flags = 0, reason_code = 0},
    ?assertEqual(0, emqx_packet:info(ack_flags, AckPkt)),
    ?assertEqual(0, emqx_packet:info(reason_code, AckPkt)),
-    ?assertEqual(undefined, emqx_packet:info(properties, AckPkt)).
+    ?assertEqual(#{}, emqx_packet:info(properties, AckPkt)).

 t_publish_info(_) ->
    PubPkt = #mqtt_packet_publish{topic_name = <<"t">>, packet_id = 1},
    ?assertEqual(1, emqx_packet:info(packet_id, PubPkt)),
    ?assertEqual(<<"t">>, emqx_packet:info(topic_name, PubPkt)),
-    ?assertEqual(undefined, emqx_packet:info(properties, PubPkt)).
+    ?assertEqual(#{}, emqx_packet:info(properties, PubPkt)).

 t_puback_info(_) ->
    AckPkt = #mqtt_packet_puback{packet_id = 1, reason_code = 0},
    ?assertEqual(1, emqx_packet:info(packet_id, AckPkt)),
    ?assertEqual(0, emqx_packet:info(reason_code, AckPkt)),
-    ?assertEqual(undefined, emqx_packet:info(properties, AckPkt)).
+    ?assertEqual(#{}, emqx_packet:info(properties, AckPkt)).

 t_subscribe_info(_) ->
    TopicFilters = [{<<"t/#">>, #{}}],
    SubPkt = #mqtt_packet_subscribe{packet_id = 1, topic_filters = TopicFilters},
    ?assertEqual(1, emqx_packet:info(packet_id, SubPkt)),
-    ?assertEqual(undefined, emqx_packet:info(properties, SubPkt)),
+    ?assertEqual(#{}, emqx_packet:info(properties, SubPkt)),
    ?assertEqual(TopicFilters, emqx_packet:info(topic_filters, SubPkt)).

 t_suback_info(_) ->
    SubackPkt = #mqtt_packet_suback{packet_id = 1, reason_codes = [0]},
    ?assertEqual(1, emqx_packet:info(packet_id, SubackPkt)),
-    ?assertEqual(undefined, emqx_packet:info(properties, SubackPkt)),
+    ?assertEqual(#{}, emqx_packet:info(properties, SubackPkt)),
    ?assertEqual([0], emqx_packet:info(reason_codes, SubackPkt)).

 t_unsubscribe_info(_) ->
    UnsubPkt = #mqtt_packet_unsubscribe{packet_id = 1, topic_filters = [<<"t/#">>]},
    ?assertEqual(1, emqx_packet:info(packet_id, UnsubPkt)),
-    ?assertEqual(undefined, emqx_packet:info(properties, UnsubPkt)),
+    ?assertEqual(#{}, emqx_packet:info(properties, UnsubPkt)),
    ?assertEqual([<<"t/#">>], emqx_packet:info(topic_filters, UnsubPkt)).

 t_unsuback_info(_) ->
    AckPkt = #mqtt_packet_unsuback{packet_id = 1, reason_codes = [0]},
    ?assertEqual(1, emqx_packet:info(packet_id, AckPkt)),
    ?assertEqual([0], emqx_packet:info(reason_codes, AckPkt)),
-    ?assertEqual(undefined, emqx_packet:info(properties, AckPkt)).
+    ?assertEqual(#{}, emqx_packet:info(properties, AckPkt)).

 t_disconnect_info(_) ->
    DisconnPkt = #mqtt_packet_disconnect{reason_code = 0},
    ?assertEqual(0, emqx_packet:info(reason_code, DisconnPkt)),
-    ?assertEqual(undefined, emqx_packet:info(properties, DisconnPkt)).
+    ?assertEqual(#{}, emqx_packet:info(properties, DisconnPkt)).

 t_auth_info(_) ->
    AuthPkt = #mqtt_packet_auth{reason_code = 0},
    ?assertEqual(0, emqx_packet:info(reason_code, AuthPkt)),
-    ?assertEqual(undefined, emqx_packet:info(properties, AuthPkt)).
+    ?assertEqual(#{}, emqx_packet:info(properties, AuthPkt)).

 t_set_props(_) ->
    Pkts = [#mqtt_packet_connect{}, #mqtt_packet_connack{}, #mqtt_packet_publish{},
@ -245,6 +244,7 @@ t_from_to_message(_) ->
    ExpectedMsg1 = emqx_message:set_flags(#{dup => false, retain => false}, ExpectedMsg),
    ExpectedMsg2 = emqx_message:set_headers(#{peerhost => {127,0,0,1},
                                              protocol => mqtt,
+                                              properties => #{},
                                              username => <<"test">>
                                             }, ExpectedMsg1),
    Pkt = #mqtt_packet{header = #mqtt_packet_header{type   = ?PUBLISH,
@ -255,10 +255,10 @@ t_from_to_message(_) ->
                                                       packet_id  = 10,
                                                       properties = #{}},
                       payload = <<"payload">>},
-    MsgFromPkt = emqx_packet:to_message(#{protocol => mqtt,
-                                          clientid => <<"clientid">>,
-                                          username => <<"test">>,
-                                          peerhost => {127,0,0,1}}, Pkt),
+    MsgFromPkt = emqx_packet:to_message(Pkt, <<"clientid">>,
+                    #{protocol => mqtt,
+                      username => <<"test">>,
+                      peerhost => {127,0,0,1}}),
    ?assertEqual(ExpectedMsg2, MsgFromPkt#message{id = emqx_message:id(ExpectedMsg),
                                                  timestamp = emqx_message:timestamp(ExpectedMsg)
                                                 }).
@ -283,7 +283,6 @@ t_will_msg(_) ->
                               will_retain = true,
                               will_qos = ?QOS_2,
                               will_topic = <<"topic">>,
-                               will_props = undefined,
                               will_payload = <<"payload">>
                              },
    Msg2 = emqx_packet:will_msg(Pkt2),
@ -297,7 +296,6 @@ t_format(_) ->
                                                                             will_retain = true,
                                                                             will_qos = ?QOS_2,
                                                                             will_topic = <<"topic">>,
-                                                                             will_props = undefined,
                                                                             will_payload = <<"payload">>}))]),
    io:format("~s", [emqx_packet:format(?CONNECT_PACKET(#mqtt_packet_connect{password = password}))]),
    io:format("~s", [emqx_packet:format(?CONNACK_PACKET(?CONNACK_SERVER))]),
--- a/test/emqx_reason_codes_SUITE.erl
+++ b/test/emqx_reason_codes_SUITE.erl
@ -20,7 +20,6 @@
 -compile(nowarn_export_all).

 -include("emqx_mqtt.hrl").
-include_lib("proper/include/proper.hrl").
 -include_lib("eunit/include/eunit.hrl").

 all() -> emqx_ct:all(?MODULE).
@ -29,124 +28,3 @@ t_frame_error(_) ->
    ?assertEqual(?RC_PACKET_TOO_LARGE, emqx_reason_codes:frame_error(frame_too_large)),
    ?assertEqual(?RC_MALFORMED_PACKET, emqx_reason_codes:frame_error(bad_packet_id)),
    ?assertEqual(?RC_MALFORMED_PACKET, emqx_reason_codes:frame_error(bad_qos)).
-
-t_prop_name_text(_) ->
-    ?assert(proper:quickcheck(prop_name_text(), prop_name_text(opts))).
-
-t_prop_compat(_) ->
-    ?assert(proper:quickcheck(prop_compat(), prop_compat(opts))).
-
-t_prop_connack_error(_) ->
-    ?assert(proper:quickcheck(prop_connack_error(), default_opts([]))).
-
-prop_name_text(opts) ->
-    default_opts([{numtests, 1000}]).
-
-prop_name_text() ->
-    ?FORALL(UnionArgs, union_args(),
-            is_atom(apply_fun(name, UnionArgs)) andalso
-            is_binary(apply_fun(text, UnionArgs))).
-
-prop_compat(opts) ->
-    default_opts([{numtests, 512}]).
-
-prop_compat() ->
-    ?FORALL(CompatArgs, compat_args(),
-            begin
-                Result = apply_fun(compat, CompatArgs),
-                is_number(Result) orelse Result =:= undefined
-            end).
-
-prop_connack_error() ->
-    ?FORALL(CONNACK_ERROR_ARGS, connack_error_args(),
-            is_integer(apply_fun(connack_error, CONNACK_ERROR_ARGS))).
-
-%%--------------------------------------------------------------------
-%% Helper
-%%--------------------------------------------------------------------
-
-default_opts() ->
-    default_opts([]).
-
-default_opts(AdditionalOpts) ->
-    [{to_file, user} | AdditionalOpts].
-
-apply_fun(Fun, Args) ->
-    apply(emqx_reason_codes, Fun, Args).
-
-%%--------------------------------------------------------------------
-%% Generator
-%%--------------------------------------------------------------------
-
-union_args() ->
-    frequency([{6, [real_mqttv3_rc(), mqttv3_version()]},
-               {43, [real_mqttv5_rc(), mqttv5_version()]}]).
-
-compat_args() ->
-    frequency([{18, [connack, compat_rc()]},
-               {2, [suback, compat_rc()]},
-               {1, [unsuback, compat_rc()]}]).
-
-connack_error_args() ->
-    [frequency([{10, connack_error()},
-                {1, unexpected_connack_error()}])].
-
-connack_error() ->
-    oneof([client_identifier_not_valid,
-           bad_username_or_password,
-           bad_clientid_or_password,
-           username_or_password_undefined,
-           password_error,
-           not_authorized,
-           server_unavailable,
-           server_busy,
-           banned,
-           bad_authentication_method]).
-
-unexpected_connack_error() ->
-    oneof([who_knows]).
-
-
-real_mqttv3_rc() ->
-    frequency([{6, mqttv3_rc()},
-               {1, unexpected_rc()}]).
-
-real_mqttv5_rc() ->
-    frequency([{43, mqttv5_rc()},
-               {2, unexpected_rc()}]).
-
-compat_rc() ->
-    frequency([{95, ?SUCHTHAT(RC , mqttv5_rc(), RC >= 16#80 orelse RC =< 2)},
-               {5, unexpected_rc()}]).
-
-mqttv3_rc() ->
-    oneof(mqttv3_rcs()).
-
-mqttv5_rc() ->
-    oneof(mqttv5_rcs()).
-
-unexpected_rc() ->
-    oneof(unexpected_rcs()).
-
-mqttv3_rcs() ->
-    [0, 1, 2, 3, 4, 5].
-
-mqttv5_rcs() ->
-    [16#00, 16#01, 16#02, 16#04, 16#10, 16#11, 16#18, 16#19,
-     16#80, 16#81, 16#82, 16#83, 16#84, 16#85, 16#86, 16#87,
-     16#88, 16#89, 16#8A, 16#8B, 16#8C, 16#8D, 16#8E, 16#8F,
-     16#90, 16#91, 16#92, 16#93, 16#94, 16#95, 16#96, 16#97,
-     16#98, 16#99, 16#9A, 16#9B, 16#9C, 16#9D, 16#9E, 16#9F,
-     16#A0, 16#A1, 16#A2].
-
-unexpected_rcs() ->
-    ReasonCodes = mqttv3_rcs() ++ mqttv5_rcs(),
-    Unexpected = lists:seq(0, 16#FF) -- ReasonCodes,
-    lists:sublist(Unexpected, 5).
-
-mqttv5_version() ->
-    ?MQTT_PROTO_V5.
-
-mqttv3_version() ->
-    oneof([?MQTT_PROTO_V3, ?MQTT_PROTO_V4]).
-
--- a/test/emqx_rpc_SUITE.erl
+++ b/test/emqx_rpc_SUITE.erl
@ -1,161 +0,0 @@
-%%--------------------------------------------------------------------
-%% Copyright (c) 2020 EMQ Technologies Co., Ltd. All Rights Reserved.
-%%
-%% Licensed under the Apache License, Version 2.0 (the "License");
-%% you may not use this file except in compliance with the License.
-%% You may obtain a copy of the License at
-%%
-%%     http://www.apache.org/licenses/LICENSE-2.0
-%%
-%% Unless required by applicable law or agreed to in writing, software
-%% distributed under the License is distributed on an "AS IS" BASIS,
-%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-%% See the License for the specific language governing permissions and
-%% limitations under the License.
-%%--------------------------------------------------------------------
-
-module(emqx_rpc_SUITE).
-
-compile(export_all).
-compile(nowarn_export_all).
-
-include_lib("proper/include/proper.hrl").
-include_lib("eunit/include/eunit.hrl").
-
-all() -> emqx_ct:all(?MODULE).
-
-t_prop_rpc(_) ->
-    ok = load(),
-    Opts = [{to_file, user}, {numtests, 10}],
-    {ok, _Apps} = application:ensure_all_started(gen_rpc),
-    ok = application:set_env(gen_rpc, call_receive_timeout, 1),
-    ok = emqx_logger:set_log_level(emergency),
-    ?assert(proper:quickcheck(prop_node(), Opts)),
-    ?assert(proper:quickcheck(prop_node_with_key(), Opts)),
-    ?assert(proper:quickcheck(prop_nodes(), Opts)),
-    ?assert(proper:quickcheck(prop_nodes_with_key(), Opts)),
-    ok = application:stop(gen_rpc),
-    ok = unload().
-
-prop_node() ->
-    ?FORALL(Node, nodename(),
-            begin
-                ?assert(emqx_rpc:cast(Node, erlang, system_time, [])),
-                case emqx_rpc:call(Node, erlang, system_time, []) of
-                    {badrpc, _Reason} -> true;
-                    Delivery when is_integer(Delivery) -> true;
-                    _Other -> false
-                end
-            end).
-
-prop_node_with_key() ->
-    ?FORALL({Node, Key}, nodename_with_key(),
-            begin
-                ?assert(emqx_rpc:cast(Key, Node, erlang, system_time, [])),
-                case emqx_rpc:call(Key, Node, erlang, system_time, []) of
-                    {badrpc, _Reason} -> true;
-                    Delivery when is_integer(Delivery) -> true;
-                    _Other -> false
-                end
-            end).
-
-prop_nodes() ->
-    ?FORALL(Nodes, nodesname(),
-            begin
-                case emqx_rpc:multicall(Nodes, erlang, system_time, []) of
-                    {badrpc, _Reason} -> true;
-                    {RealResults, RealBadNodes}
-                      when is_list(RealResults);
-                           is_list(RealBadNodes) ->
-                        true;
-                    _Other -> false
-                end
-            end).
-
-prop_nodes_with_key() ->
-    ?FORALL({Nodes, Key}, nodesname_with_key(),
-            begin
-                case emqx_rpc:multicall(Key, Nodes, erlang, system_time, []) of
-                    {badrpc, _Reason} -> true;
-                    {RealResults, RealBadNodes}
-                      when is_list(RealResults);
-                           is_list(RealBadNodes) ->
-                        true;
-                    _Other -> false
-                end
-            end).
-
-%%--------------------------------------------------------------------
-%%  helper
-%%--------------------------------------------------------------------
-
-load() ->
-    ok = meck:new(gen_rpc, [passthrough, no_history]),
-    ok = meck:expect(gen_rpc, multicall,
-                     fun(Nodes, Mod, Fun, Args) ->
-                             gen_rpc:multicall(Nodes, Mod, Fun, Args, 1)
-                     end).
-
-unload() ->
-    ok = meck:unload(gen_rpc).
-
-%%--------------------------------------------------------------------
-%% Generator
-%%--------------------------------------------------------------------
-
-nodename() ->
-    ?LET({NodePrefix, HostName},
-         {node_prefix(), hostname()},
-         begin
-             Node = NodePrefix ++ "@" ++ HostName,
-             list_to_atom(Node)
-         end).
-
-nodename_with_key() ->
-    ?LET({NodePrefix, HostName, Key},
-         {node_prefix(), hostname(), choose(0, 10)},
-         begin
-             Node = NodePrefix ++ "@" ++ HostName,
-             {list_to_atom(Node), Key}
-         end).
-
-nodesname() ->
-    oneof([list(nodename()), ['emqxct@127.0.0.1']]).
-
-nodesname_with_key() ->
-    oneof([{list(nodename()), choose(0, 10)}, {['emqxct@127.0.0.1'], 1}]).
-
-node_prefix() ->
-    oneof(["emqxct", text_like()]).
-
-text_like() ->
-    ?SUCHTHAT(Text, list(range($a, $z)), (length(Text) =< 5 andalso length(Text) > 0)).
-
-hostname() ->
-    oneof([ipv4_address(), ipv6_address(), "127.0.0.1", "localhost"]).
-
-ipv4_address() ->
-        ?LET({Num1, Num2, Num3, Num4},
-             { choose(0, 255)
-             , choose(0, 255)
-             , choose(0, 255)
-             , choose(0, 255)},
-             make_ip([Num1, Num2, Num3, Num4], ipv4)).
-
-ipv6_address() ->
-        ?LET({Num1, Num2, Num3, Num4, Num5, Num6},
-             { choose(0, 65535)
-             , choose(0, 65535)
-             , choose(0, 65535)
-             , choose(0, 65535)
-             , choose(0, 65535)
-             , choose(0, 65535)},
-             make_ip([Num1, Num2, Num3, Num4, Num5, Num6], ipv6)).
-
-
-make_ip(NumList, ipv4) when is_list(NumList) ->
-    string:join([integer_to_list(Num) || Num <- NumList], ".");
-make_ip(NumList, ipv6) when is_list(NumList) ->
-    string:join([integer_to_list(Num) || Num <- NumList], ":");
-make_ip(_List, _protocol) ->
-    "127.0.0.1".
--- a/test/emqx_session_SUITE.erl
+++ b/test/emqx_session_SUITE.erl
@ -20,7 +20,6 @@
 -compile(nowarn_export_all).

 -include("emqx_mqtt.hrl").
-include_lib("proper/include/proper.hrl").
 -include_lib("eunit/include/eunit.hrl").

 all() -> emqx_ct:all(?MODULE).
@ -116,9 +115,9 @@ t_is_subscriptions_full_true(_) ->
 t_unsubscribe(_) ->
    ok = meck:expect(emqx_broker, unsubscribe, fun(_) -> ok end),
    Session = session(#{subscriptions => #{<<"#">> => subopts()}}),
-    {ok, Session1} = emqx_session:unsubscribe(clientinfo(), <<"#">>, Session),
+    {ok, Session1} = emqx_session:unsubscribe(clientinfo(), <<"#">>, #{}, Session),
    {error, ?RC_NO_SUBSCRIPTION_EXISTED} =
-        emqx_session:unsubscribe(clientinfo(), <<"#">>, Session1).
+        emqx_session:unsubscribe(clientinfo(), <<"#">>, #{}, Session1).

 t_publish_qos0(_) ->
    ok = meck:expect(emqx_broker, publish, fun(_) -> [] end),
--- a/test/emqx_sys_SUITE.erl
+++ b/test/emqx_sys_SUITE.erl
@ -19,16 +19,8 @@
 -compile(export_all).
 -compile(nowarn_export_all).

-include_lib("proper/include/proper.hrl").
 -include_lib("eunit/include/eunit.hrl").

-define(mock_modules,
-        [ emqx_metrics
-        , emqx_stats
-        , emqx_broker
-        , ekka_mnesia
-        ]).
-
 all() -> emqx_ct:all(?MODULE).

 init_per_suite(Config) ->
@ -66,95 +58,3 @@ t_uptime(_) ->

 % t_info(_) ->
 %     error('TODO').
-
-t_prop_sys(_) ->
-    Opts = [{numtests, 100}, {to_file, user}],
-    ok = load(?mock_modules),
-    ?assert(proper:quickcheck(prop_sys(), Opts)),
-    ok = unload(?mock_modules).
-
-prop_sys() ->
-    ?FORALL(Cmds, commands(?MODULE),
-        begin
-            {ok, _Pid} = emqx_sys:start_link(),
-            {History, State, Result} = run_commands(?MODULE, Cmds),
-            ok = emqx_sys:stop(),
-            ?WHENFAIL(io:format("History: ~p\nState: ~p\nResult: ~p\n",
-                                [History,State,Result]),
-                      aggregate(command_names(Cmds), true))
-        end).
-
-load(Modules) ->
-    [mock(Module) || Module <- Modules],
-    ok.
-
-unload(Modules) ->
-    lists:foreach(fun(Module) ->
-                          ok = meck:unload(Module)
-                  end, Modules).
-
-mock(Module) ->
-    ok = meck:new(Module, [passthrough, no_history]),
-    do_mock(Module).
-
-do_mock(emqx_broker) ->
-    meck:expect(emqx_broker, publish,
-                fun(Msg) -> {node(), <<"test">>, Msg} end),
-    meck:expect(emqx_broker, safe_publish,
-                fun(Msg) -> {node(), <<"test">>, Msg} end);
-do_mock(emqx_stats) ->
-    meck:expect(emqx_stats, getstats, fun() -> [0] end);
-do_mock(ekka_mnesia) ->
-    meck:expect(ekka_mnesia, running_nodes, fun() -> [node()] end);
-do_mock(emqx_metrics) ->
-    meck:expect(emqx_metrics, all, fun() -> [{hello, 3}] end).
-
-unmock() ->
-    meck:unload(emqx_broker).
-
-%%%%%%%%%%%%%
-%%% MODEL %%%
-%%%%%%%%%%%%%
-%% @doc Initial model value at system start. Should be deterministic.
-initial_state() ->
-    #{}.
-
-%% @doc List of possible commands to run against the system
-command(_State) ->
-    oneof([{call, emqx_sys, info, []},
-           {call, emqx_sys, version, []},
-           {call, emqx_sys, uptime, []},
-           {call, emqx_sys, datetime, []},
-           {call, emqx_sys, sysdescr, []},
-           {call, emqx_sys, sys_interval, []},
-           {call, emqx_sys, sys_heatbeat_interval, []},
-           %------------ unexpected message ----------------------%
-           {call, emqx_sys, handle_call, [emqx_sys, other, state]},
-           {call, emqx_sys, handle_cast, [emqx_sys, other]},
-           {call, emqx_sys, handle_info, [info, state]}
-          ]).
-
-precondition(_State, {call, _Mod, _Fun, _Args}) ->
-    timer:sleep(1),
-    true.
-
-postcondition(_State, {call, emqx_sys, info, []}, Info) ->
-    is_list(Info) andalso length(Info) =:= 4;
-postcondition(_State, {call, emqx_sys, version, []}, Version) ->
-    is_list(Version);
-postcondition(_State, {call, emqx_sys, uptime, []}, Uptime) ->
-    is_list(Uptime);
-postcondition(_State, {call, emqx_sys, datetime, []}, Datetime) ->
-    is_list(Datetime);
-postcondition(_State, {call, emqx_sys, sysdescr, []}, Sysdescr) ->
-    is_list(Sysdescr);
-postcondition(_State, {call, emqx_sys, sys_interval, []}, SysInterval) ->
-    is_integer(SysInterval) andalso SysInterval > 0;
-postcondition(_State, {call, emqx_sys, sys_heartbeat_interval, []}, SysHeartInterval) ->
-    is_integer(SysHeartInterval) andalso SysHeartInterval > 0;
-postcondition(_State, {call, _Mod, _Fun, _Args}, _Res) ->
-    true.
-
-next_state(State, _Res, {call, _Mod, _Fun, _Args}) ->
-    NewState = State,
-    NewState.
--- a/test/emqx_topic_SUITE.erl
+++ b/test/emqx_topic_SUITE.erl
@ -26,7 +26,6 @@
        [ wildcard/1
        , match/2
        , validate/1
-        , triples/1
        , prepend/2
        , join/1
        , words/1
@ -143,18 +142,7 @@ t_sigle_level_validate(_) ->
    true = validate({filter, <<"sport/+/player1">>}),
    ok = ?catch_error(topic_invalid_char, validate({filter, <<"sport+">>})).

-t_triples(_) ->
-    Triples = [{root,<<"a">>,<<"a">>},
-               {<<"a">>,<<"b">>,<<"a/b">>},
-               {<<"a/b">>,<<"c">>,<<"a/b/c">>}],
-    ?assertEqual(Triples, triples(<<"a/b/c">>)).
-
-t_triples_perf(_) ->
-    Topic = <<"/abkc/19383/192939/akakdkkdkak/xxxyyuya/akakak">>,
-    ok = bench('triples/1', fun emqx_topic:triples/1, [Topic]).
-
 t_prepend(_) ->
-    ?assertEqual(<<"a/b/c">>, prepend(root, <<"a/b/c">>)),
    ?assertEqual(<<"ab">>, prepend(undefined, <<"ab">>)),
    ?assertEqual(<<"a/b">>, prepend(<<>>, <<"a/b">>)),
    ?assertEqual(<<"x/a/b">>, prepend("x/", <<"a/b">>)),
--- a/test/emqx_trie_SUITE.erl
+++ b/test/emqx_trie_SUITE.erl
@ -141,6 +141,12 @@ t_delete3(_) ->
          end,
    ?assertEqual({atomic, {[], []}}, trans(Fun)).

+t_triples(_) ->
+    Triples = [{root,<<"a">>,<<"a">>},
+               {<<"a">>,<<"b">>,<<"a/b">>},
+               {<<"a/b">>,<<"c">>,<<"a/b/c">>}],
+    ?assertEqual(Triples, emqx_trie:triples(<<"a/b/c">>)).
+
 clear_tables() ->
    lists:foreach(fun mnesia:clear_table/1, ?TRIE_TABS).

--- a/test/emqx_vm_SUITE.erl
+++ b/test/emqx_vm_SUITE.erl
@ -80,8 +80,7 @@ t_get_port_info(_Config) ->
    {ok, Sock} = gen_tcp:connect("localhost", 5678, [binary, {packet, 0}]),
    emqx_vm:get_port_info(),
    ok = gen_tcp:close(Sock),
-    [Port | _] = erlang:ports(),
-    [{connected, _}, {name, _}] = emqx_vm:port_info(Port, [connected, name]).
+    [Port | _] = erlang:ports().

 t_transform_port(_Config) ->
    [Port | _] = erlang:ports(),
--- a/test/emqx_ws_connection_SUITE.erl
+++ b/test/emqx_ws_connection_SUITE.erl
@ -304,7 +304,7 @@ t_parse_incoming(_) ->
    St = ?ws_conn:parse_incoming(<<48,3>>, st()),
    St1 = ?ws_conn:parse_incoming(<<0,1,116>>, St),
    Packet = ?PUBLISH_PACKET(?QOS_0, <<"t">>, undefined, <<>>),
-    [{incoming, Packet}] = ?ws_conn:info(postponed, St1).
+    ?assertMatch([{incoming, Packet}], ?ws_conn:info(postponed, St1)).

 t_parse_incoming_frame_error(_) ->
    St = ?ws_conn:parse_incoming(<<3,2,1,0>>, st()),
--- a/test/props/prop_emqx_base62.erl
+++ b/test/props/prop_emqx_base62.erl
@ -14,24 +14,14 @@
 %% limitations under the License.
 %%--------------------------------------------------------------------

-module(emqx_base62_SUITE).
-
-compile(export_all).
-compile(nowarn_export_all).
+-module(prop_emqx_base62).

 -include_lib("proper/include/proper.hrl").
-include_lib("eunit/include/eunit.hrl").

-all() -> emqx_ct:all(?MODULE).
+%%--------------------------------------------------------------------
+%% Properties
+%%--------------------------------------------------------------------

-t_proper_base62(_) ->
-    Opts = [{numtests, 100}, {to_file, user}],
-    ?assert(proper:quickcheck(prop_symmetric(), Opts)),
-    ?assert(proper:quickcheck(prop_size(), Opts)).
-
-%%%%%%%%%%%%%%%%%%
-%%% Properties %%%
-%%%%%%%%%%%%%%%%%%
 prop_symmetric() ->
    ?FORALL(Data, raw_data(),
        begin
@ -46,9 +36,10 @@ prop_size() ->
             base62_size(Data, Encoded)
         end).

-%%%%%%%%%%%%%%%
-%%% Helpers %%%
-%%%%%%%%%%%%%%%
+%%--------------------------------------------------------------------
+%% Helpers
+%%--------------------------------------------------------------------
+
 to_binary(Data) when is_list(Data) ->
    unicode:characters_to_binary(Data);
 to_binary(Data) when is_integer(Data) ->
@ -73,7 +64,9 @@ base62_size(Data, Encoded) ->
            EncodedSize >= RangeStart andalso EncodedSize =< RangeEnd
    end.

-%%%%%%%%%%%%%%%%%%
-%%% Generators %%%
-%%%%%%%%%%%%%%%%%%
-raw_data() -> oneof([integer(), string(), binary()]).
+%%--------------------------------------------------------------------
+%% Generators
+%%--------------------------------------------------------------------
+
+raw_data() ->
+    oneof([integer(), string(), binary()]).
--- a/test/props/prop_emqx_frame.erl
+++ b/test/props/prop_emqx_frame.erl
@ -0,0 +1,62 @@
+%%--------------------------------------------------------------------
+%% Copyright (c) 2020 EMQ Technologies Co., Ltd. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%--------------------------------------------------------------------
+
+-module(prop_emqx_frame).
+
+-include("emqx_mqtt.hrl").
+-include_lib("proper/include/proper.hrl").
+
+%%--------------------------------------------------------------------
+%% Properties
+%%--------------------------------------------------------------------
+
+prop_serialize_parse_connect() ->
+    ?FORALL(Opts = #{version := ProtoVer}, parse_opts(),
+            begin
+                ProtoName = proplists:get_value(ProtoVer, ?PROTOCOL_NAMES),
+                Packet = ?CONNECT_PACKET(#mqtt_packet_connect{
+                                            proto_name   = ProtoName,
+                                            proto_ver    = ProtoVer,
+                                            clientid     = <<"clientId">>,
+                                            will_qos     = ?QOS_1,
+                                            will_flag    = true,
+                                            will_retain  = true,
+                                            will_topic   = <<"will">>,
+                                            will_props   = #{},
+                                            will_payload = <<"bye">>,
+                                            clean_start  = true,
+                                            properties = #{}
+                                           }),
+                Packet =:= parse_serialize(Packet, Opts)
+            end).
+
+%%--------------------------------------------------------------------
+%% Helpers
+%%--------------------------------------------------------------------
+
+parse_serialize(Packet, Opts) when is_map(Opts) ->
+    Ver = maps:get(version, Opts, ?MQTT_PROTO_V4),
+    Bin = iolist_to_binary(emqx_frame:serialize(Packet, Ver)),
+    ParseState = emqx_frame:initial_parse_state(Opts),
+    {ok, NPacket, <<>>, _} = emqx_frame:parse(Bin, ParseState),
+    NPacket.
+
+%%--------------------------------------------------------------------
+%% Generators
+%%--------------------------------------------------------------------
+
+parse_opts() ->
+    ?LET(PropList, [{strict_mode, boolean()}, {version, range(4,5)}], maps:from_list(PropList)).
--- a/test/props/prop_emqx_json.erl
+++ b/test/props/prop_emqx_json.erl
@ -0,0 +1,196 @@
+%%--------------------------------------------------------------------
+%% Copyright (c) 2020 EMQ Technologies Co., Ltd. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%--------------------------------------------------------------------
+
+-module(prop_emqx_json).
+
+-import(emqx_json,
+         [ decode/1
+         , decode/2
+         , encode/1
+         , safe_decode/1
+         , safe_decode/2
+         , safe_encode/1
+         ]).
+
+-include_lib("proper/include/proper.hrl").
+
+%%--------------------------------------------------------------------
+%% Properties
+%%--------------------------------------------------------------------
+
+prop_json_basic() ->
+    ?FORALL(T, json_basic(),
+            begin
+                {ok, J} = safe_encode(T),
+                {ok, T} = safe_decode(J),
+                T = decode(encode(T)),
+                true
+            end).
+
+prop_json_basic_atom() ->
+    ?FORALL(T0,  latin_atom(),
+            begin
+                T = atom_to_binary(T0, utf8),
+                {ok, J} = safe_encode(T0),
+                {ok, T} = safe_decode(J),
+                T = decode(encode(T0)),
+                true
+            end).
+
+prop_object_proplist_to_proplist() ->
+    ?FORALL(T, json_object(),
+            begin
+                {ok, J} = safe_encode(T),
+                {ok, T} = safe_decode(J),
+                T = decode(encode(T)),
+                true
+            end).
+
+prop_object_map_to_map() ->
+    ?FORALL(T, json_object_map(),
+            begin
+                {ok, J} = safe_encode(T),
+                {ok, T} = safe_decode(J, [return_maps]),
+                T = decode(encode(T), [return_maps]),
+                true
+            end).
+
+%% The duplicated key will be overriden
+prop_object_proplist_to_map() ->
+    ?FORALL(T0, json_object(),
+           begin
+               T = to_map(T0),
+               {ok, J} = safe_encode(T0),
+               {ok, T} = safe_decode(J, [return_maps]),
+               T = decode(encode(T0), [return_maps]),
+               true
+           end).
+
+prop_object_map_to_proplist() ->
+    ?FORALL(T0, json_object_map(),
+           begin
+               %% jiffy encode a map with descending order, that is,
+               %% it is opposite with maps traversal sequence
+               %% see: the `to_list` implementation
+               T = to_list(T0),
+               {ok, J} = safe_encode(T0),
+               {ok, T} = safe_decode(J),
+               T = decode(encode(T0)),
+               true
+           end).
+
+prop_safe_encode() ->
+    ?FORALL(T, invalid_json_term(),
+           begin
+               {error, _} = safe_encode(T), true
+           end).
+
+prop_safe_decode() ->
+    ?FORALL(T, invalid_json_str(),
+           begin
+               {error, _} = safe_decode(T), true
+           end).
+
+%%--------------------------------------------------------------------
+%% Helpers
+%%--------------------------------------------------------------------
+
+to_map([{_, _}|_] = L) ->
+    lists:foldl(
+      fun({Name, Value}, Acc) ->
+        Acc#{Name => to_map(Value)}
+      end, #{}, L);
+to_map(L) when is_list(L) ->
+    [to_map(E) || E <- L];
+to_map(T) -> T.
+
+to_list(L) when is_list(L) ->
+    [to_list(E) || E <- L];
+to_list(M) when is_map(M) ->
+    maps:fold(
+      fun(K, V, Acc) ->
+        [{K, to_list(V)}|Acc]
+      end, [], M);
+to_list(T) -> T.
+
+%%--------------------------------------------------------------------
+%% Generators (https://tools.ietf.org/html/rfc8259)
+%%--------------------------------------------------------------------
+
+%% true, false, null, and number(), string()
+json_basic() ->
+    oneof([true, false, null, number(), json_string()]).
+
+latin_atom() ->
+    ?LET(L, list(latin_char()), list_to_atom(L)).
+
+latin_char() ->
+    L = lists:concat([lists:seq($0, $9),
+                      lists:seq($a, $z),
+                      lists:seq($A, $Z)]),
+    oneof(L).
+
+json_string() -> utf8().
+
+json_object() ->
+    oneof([json_array_1(), json_object_1(), json_array_object_1(),
+           json_array_2(), json_object_2(), json_array_object_2()]).
+
+json_object_map() ->
+    ?LET(L, json_object(), to_map(L)).
+
+json_array_1() ->
+    list(json_basic()).
+
+json_array_2() ->
+    list([json_basic(), json_array_1()]).
+
+json_object_1() ->
+    list({json_key(), json_basic()}).
+
+json_object_2() ->
+    list({json_key(), oneof([json_basic(),
+                             json_array_1(),
+                             json_object_1()])}).
+
+json_array_object_1() ->
+    list(json_object_1()).
+
+json_array_object_2() ->
+    list(json_object_2()).
+
+%% @private
+json_key() ->
+    ?LET(K, latin_atom(), atom_to_binary(K, utf8)).
+
+invalid_json_term() ->
+    ?SUCHTHAT(T, tuple(), (tuple_size(T) /= 1)).
+
+invalid_json_str() ->
+    ?LET(T, json_object_2(), chaos(encode(T))).
+
+%% @private
+chaos(S) when is_binary(S) ->
+    T = [$\r, $\n, $", ${, $}, $[, $], $:, $,],
+    iolist_to_binary(chaos(binary_to_list(S), 100, T)).
+
+chaos(S, 0, _) ->
+    S;
+chaos(S, N, T) ->
+    I = rand:uniform(length(S)),
+    {L1, L2} = lists:split(I, S),
+    chaos(lists:flatten([L1, lists:nth(rand:uniform(length(T)), T), L2]), N-1, T).
+
--- a/test/props/prop_emqx_psk.erl
+++ b/test/props/prop_emqx_psk.erl
@ -14,48 +14,46 @@
 %% limitations under the License.
 %%--------------------------------------------------------------------

-module(emqx_psk_SUITE).

-compile(export_all).
-compile(nowarn_export_all).
+-module(prop_emqx_psk).

 -include_lib("proper/include/proper.hrl").
-include_lib("eunit/include/eunit.hrl").
-include_lib("common_test/include/ct.hrl").

-all() -> emqx_ct:all(?MODULE).
+-define(ALL(Vars, Types, Exprs),
+        ?SETUP(fun() ->
+            State = do_setup(),
+            fun() -> do_teardown(State) end
+         end, ?FORALL(Vars, Types, Exprs))).

-t_lookup(_) ->
-    ok = load(),
-    ok = emqx_logger:set_log_level(emergency),
-    Opts = [{to_file, user}, {numtests, 10}],
-    ?assert(proper:quickcheck(prop_lookup(), Opts)),
-    ok = unload(),
-    ok = emqx_logger:set_log_level(error).
+%%--------------------------------------------------------------------
+%% Properties
+%%--------------------------------------------------------------------

 prop_lookup() ->
-    ?FORALL({ClientPSKID, UserState},
-            {client_pskid(), user_state()},
-            begin
-                case emqx_psk:lookup(psk, ClientPSKID, UserState) of
-                    {ok, _Result} -> true;
-                    error -> true;
-                    _Other -> false
-                end
-            end).
+    ?ALL({ClientPSKID, UserState},
+         {client_pskid(), user_state()},
+         begin
+             case emqx_psk:lookup(psk, ClientPSKID, UserState) of
+                 {ok, _Result} -> true;
+                 error -> true;
+                 _Other -> false
+             end
+         end).

 %%--------------------------------------------------------------------
 %% Helper
 %%--------------------------------------------------------------------

-load() ->
+do_setup() ->
+    ok = emqx_logger:set_log_level(emergency),
    ok = meck:new(emqx_hooks, [passthrough, no_history]),
    ok = meck:expect(emqx_hooks, run_fold,
                    fun('tls_handshake.psk_lookup', [ClientPSKID], not_found) ->
                            unicode:characters_to_binary(ClientPSKID)
                    end).

-unload() ->
+do_teardown(_) ->
+    ok = emqx_logger:set_log_level(error),
    ok = meck:unload(emqx_hooks).

 %%--------------------------------------------------------------------
@ -65,3 +63,4 @@ unload() ->
 client_pskid() -> oneof([string(), integer(), [1, [-1]]]).

 user_state() -> term().
+
--- a/test/props/prop_emqx_reason_codes.erl
+++ b/test/props/prop_emqx_reason_codes.erl
@ -0,0 +1,123 @@
+%%--------------------------------------------------------------------
+%% Copyright (c) 2020 EMQ Technologies Co., Ltd. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%--------------------------------------------------------------------
+
+-module(prop_emqx_reason_codes).
+
+-include("emqx_mqtt.hrl").
+-include_lib("proper/include/proper.hrl").
+
+%%--------------------------------------------------------------------
+%% Properties
+%%--------------------------------------------------------------------
+
+prop_name_text() ->
+    ?FORALL(UnionArgs, union_args(),
+            is_atom(apply_fun(name, UnionArgs)) andalso
+            is_binary(apply_fun(text, UnionArgs))).
+
+prop_compat() ->
+    ?FORALL(CompatArgs, compat_args(),
+            begin
+                Result = apply_fun(compat, CompatArgs),
+                is_number(Result) orelse Result =:= undefined
+            end).
+
+prop_connack_error() ->
+    ?FORALL(CONNACK_ERROR_ARGS, connack_error_args(),
+            is_integer(apply_fun(connack_error, CONNACK_ERROR_ARGS))).
+
+%%--------------------------------------------------------------------
+%% Helper
+%%--------------------------------------------------------------------
+
+apply_fun(Fun, Args) ->
+    apply(emqx_reason_codes, Fun, Args).
+
+%%--------------------------------------------------------------------
+%% Generator
+%%--------------------------------------------------------------------
+
+union_args() ->
+    frequency([{6, [real_mqttv3_rc(), mqttv3_version()]},
+               {43, [real_mqttv5_rc(), mqttv5_version()]}]).
+
+compat_args() ->
+    frequency([{18, [connack, compat_rc()]},
+               {2, [suback, compat_rc()]},
+               {1, [unsuback, compat_rc()]}]).
+
+connack_error_args() ->
+    [frequency([{10, connack_error()},
+                {1, unexpected_connack_error()}])].
+
+connack_error() ->
+    oneof([client_identifier_not_valid,
+           bad_username_or_password,
+           bad_clientid_or_password,
+           username_or_password_undefined,
+           password_error,
+           not_authorized,
+           server_unavailable,
+           server_busy,
+           banned,
+           bad_authentication_method]).
+
+unexpected_connack_error() ->
+    oneof([who_knows]).
+
+
+real_mqttv3_rc() ->
+    frequency([{6, mqttv3_rc()},
+               {1, unexpected_rc()}]).
+
+real_mqttv5_rc() ->
+    frequency([{43, mqttv5_rc()},
+               {2, unexpected_rc()}]).
+
+compat_rc() ->
+    frequency([{95, ?SUCHTHAT(RC , mqttv5_rc(), RC >= 16#80 orelse RC =< 2)},
+               {5, unexpected_rc()}]).
+
+mqttv3_rc() ->
+    oneof(mqttv3_rcs()).
+
+mqttv5_rc() ->
+    oneof(mqttv5_rcs()).
+
+unexpected_rc() ->
+    oneof(unexpected_rcs()).
+
+mqttv3_rcs() ->
+    [0, 1, 2, 3, 4, 5].
+
+mqttv5_rcs() ->
+    [16#00, 16#01, 16#02, 16#04, 16#10, 16#11, 16#18, 16#19,
+     16#80, 16#81, 16#82, 16#83, 16#84, 16#85, 16#86, 16#87,
+     16#88, 16#89, 16#8A, 16#8B, 16#8C, 16#8D, 16#8E, 16#8F,
+     16#90, 16#91, 16#92, 16#93, 16#94, 16#95, 16#96, 16#97,
+     16#98, 16#99, 16#9A, 16#9B, 16#9C, 16#9D, 16#9E, 16#9F,
+     16#A0, 16#A1, 16#A2].
+
+unexpected_rcs() ->
+    ReasonCodes = mqttv3_rcs() ++ mqttv5_rcs(),
+    Unexpected = lists:seq(0, 16#FF) -- ReasonCodes,
+    lists:sublist(Unexpected, 5).
+
+mqttv5_version() ->
+    ?MQTT_PROTO_V5.
+
+mqttv3_version() ->
+    oneof([?MQTT_PROTO_V3, ?MQTT_PROTO_V4]).
--- a/test/props/prop_emqx_rpc.erl
+++ b/test/props/prop_emqx_rpc.erl
@ -0,0 +1,132 @@
+%%--------------------------------------------------------------------
+%% Copyright (c) 2020 EMQ Technologies Co., Ltd. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%--------------------------------------------------------------------
+
+-module(prop_emqx_rpc).
+
+-include_lib("proper/include/proper.hrl").
+-include_lib("eunit/include/eunit.hrl").
+
+-define(ALL(Vars, Types, Exprs),
+        ?SETUP(fun() ->
+            State = do_setup(),
+            fun() -> do_teardown(State) end
+         end, ?FORALL(Vars, Types, Exprs))).
+
+%%--------------------------------------------------------------------
+%% Properties
+%%--------------------------------------------------------------------
+
+prop_node() ->
+    ?ALL(Node, nodename(),
+         begin
+             ?assert(emqx_rpc:cast(Node, erlang, system_time, [])),
+             case emqx_rpc:call(Node, erlang, system_time, []) of
+                 {badrpc, _Reason} -> true;
+                 Delivery when is_integer(Delivery) -> true;
+                 _Other -> false
+             end
+         end).
+
+prop_node_with_key() ->
+    ?ALL({Node, Key}, nodename_with_key(),
+         begin
+             ?assert(emqx_rpc:cast(Key, Node, erlang, system_time, [])),
+             case emqx_rpc:call(Key, Node, erlang, system_time, []) of
+                 {badrpc, _Reason} -> true;
+                 Delivery when is_integer(Delivery) -> true;
+                 _Other -> false
+             end
+         end).
+
+prop_nodes() ->
+    ?ALL(Nodes, nodesname(),
+         begin
+             case emqx_rpc:multicall(Nodes, erlang, system_time, []) of
+                 {badrpc, _Reason} -> true;
+                 {RealResults, RealBadNodes}
+                   when is_list(RealResults);
+                        is_list(RealBadNodes) ->
+                     true;
+                 _Other -> false
+             end
+         end).
+
+prop_nodes_with_key() ->
+    ?ALL({Nodes, Key}, nodesname_with_key(),
+         begin
+             case emqx_rpc:multicall(Key, Nodes, erlang, system_time, []) of
+                 {badrpc, _Reason} -> true;
+                 {RealResults, RealBadNodes}
+                   when is_list(RealResults);
+                        is_list(RealBadNodes) ->
+                     true;
+                 _Other -> false
+             end
+         end).
+
+%%--------------------------------------------------------------------
+%%  Helper
+%%--------------------------------------------------------------------
+
+do_setup() ->
+    {ok, _Apps} = application:ensure_all_started(gen_rpc),
+    ok = application:set_env(gen_rpc, call_receive_timeout, 1),
+    ok = emqx_logger:set_log_level(emergency),
+    ok = meck:new(gen_rpc, [passthrough, no_history]),
+    ok = meck:expect(gen_rpc, multicall,
+                     fun(Nodes, Mod, Fun, Args) ->
+                             gen_rpc:multicall(Nodes, Mod, Fun, Args, 1)
+                     end).
+
+do_teardown(_) ->
+    ok = emqx_logger:set_log_level(debug),
+    ok = application:stop(gen_rpc),
+    ok = meck:unload(gen_rpc).
+
+%%--------------------------------------------------------------------
+%% Generator
+%%--------------------------------------------------------------------
+
+nodename() ->
+    ?LET({NodePrefix, HostName},
+         {node_prefix(), hostname()},
+         begin
+             Node = NodePrefix ++ "@" ++ HostName,
+             list_to_atom(Node)
+         end).
+
+nodename_with_key() ->
+    ?LET({NodePrefix, HostName, Key},
+         {node_prefix(), hostname(), choose(0, 10)},
+         begin
+             Node = NodePrefix ++ "@" ++ HostName,
+             {list_to_atom(Node), Key}
+         end).
+
+nodesname() ->
+    oneof([list(nodename()), [node()]]).
+
+nodesname_with_key() ->
+    oneof([{list(nodename()), choose(0, 10)}, {[node()], 1}]).
+
+node_prefix() ->
+    oneof(["emqxct", text_like()]).
+
+text_like() ->
+    ?SUCHTHAT(Text, list(range($a, $z)), (length(Text) =< 5 andalso length(Text) > 0)).
+
+hostname() ->
+    oneof(["127.0.0.1", "localhost"]).
--- a/test/props/prop_emqx_sys.erl
+++ b/test/props/prop_emqx_sys.erl
@ -0,0 +1,133 @@
+%%--------------------------------------------------------------------
+%% Copyright (c) 2020 EMQ Technologies Co., Ltd. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%--------------------------------------------------------------------
+
+-module(prop_emqx_sys).
+
+-include_lib("proper/include/proper.hrl").
+
+-export([ initial_state/0
+        , command/1
+        , precondition/2
+        , postcondition/3
+        , next_state/3
+        ]).
+
+-define(mock_modules,
+        [ emqx_metrics
+        , emqx_stats
+        , emqx_broker
+        , ekka_mnesia
+        ]).
+
+-define(ALL(Vars, Types, Exprs),
+        ?SETUP(fun() ->
+            State = do_setup(),
+            fun() -> do_teardown(State) end
+         end, ?FORALL(Vars, Types, Exprs))).
+
+%%--------------------------------------------------------------------
+%% Properties
+%%--------------------------------------------------------------------
+
+prop_sys() ->
+    ?ALL(Cmds, commands(?MODULE),
+        begin
+            {ok, _Pid} = emqx_sys:start_link(),
+            {History, State, Result} = run_commands(?MODULE, Cmds),
+            ok = emqx_sys:stop(),
+            ?WHENFAIL(io:format("History: ~p\nState: ~p\nResult: ~p\n",
+                                [History,State,Result]),
+                      aggregate(command_names(Cmds), true))
+        end).
+
+%%--------------------------------------------------------------------
+%% Helpers
+%%--------------------------------------------------------------------
+
+do_setup() ->
+    ok = emqx_logger:set_log_level(emergency),
+    [mock(Mod) || Mod <- ?mock_modules],
+    ok.
+
+do_teardown(_) ->
+    ok = emqx_logger:set_log_level(error),
+    [ok = meck:unload(Mod) || Mod <- ?mock_modules],
+    ok.
+
+mock(Module) ->
+    ok = meck:new(Module, [passthrough, no_history]),
+    do_mock(Module).
+
+do_mock(emqx_broker) ->
+    meck:expect(emqx_broker, publish,
+                fun(Msg) -> {node(), <<"test">>, Msg} end),
+    meck:expect(emqx_broker, safe_publish,
+                fun(Msg) -> {node(), <<"test">>, Msg} end);
+do_mock(emqx_stats) ->
+    meck:expect(emqx_stats, getstats, fun() -> [0] end);
+do_mock(ekka_mnesia) ->
+    meck:expect(ekka_mnesia, running_nodes, fun() -> [node()] end);
+do_mock(emqx_metrics) ->
+    meck:expect(emqx_metrics, all, fun() -> [{hello, 3}] end).
+
+%%--------------------------------------------------------------------
+%% MODEL
+%%--------------------------------------------------------------------
+
+%% @doc Initial model value at system start. Should be deterministic.
+initial_state() ->
+    #{}.
+
+%% @doc List of possible commands to run against the system
+command(_State) ->
+    oneof([{call, emqx_sys, info, []},
+           {call, emqx_sys, version, []},
+           {call, emqx_sys, uptime, []},
+           {call, emqx_sys, datetime, []},
+           {call, emqx_sys, sysdescr, []},
+           {call, emqx_sys, sys_interval, []},
+           {call, emqx_sys, sys_heatbeat_interval, []},
+           %------------ unexpected message ----------------------%
+           {call, emqx_sys, handle_call, [emqx_sys, other, state]},
+           {call, emqx_sys, handle_cast, [emqx_sys, other]},
+           {call, emqx_sys, handle_info, [info, state]}
+          ]).
+
+precondition(_State, {call, _Mod, _Fun, _Args}) ->
+    timer:sleep(1),
+    true.
+
+postcondition(_State, {call, emqx_sys, info, []}, Info) ->
+    is_list(Info) andalso length(Info) =:= 4;
+postcondition(_State, {call, emqx_sys, version, []}, Version) ->
+    is_list(Version);
+postcondition(_State, {call, emqx_sys, uptime, []}, Uptime) ->
+    is_list(Uptime);
+postcondition(_State, {call, emqx_sys, datetime, []}, Datetime) ->
+    is_list(Datetime);
+postcondition(_State, {call, emqx_sys, sysdescr, []}, Sysdescr) ->
+    is_list(Sysdescr);
+postcondition(_State, {call, emqx_sys, sys_interval, []}, SysInterval) ->
+    is_integer(SysInterval) andalso SysInterval > 0;
+postcondition(_State, {call, emqx_sys, sys_heartbeat_interval, []}, SysHeartInterval) ->
+    is_integer(SysHeartInterval) andalso SysHeartInterval > 0;
+postcondition(_State, {call, _Mod, _Fun, _Args}, _Res) ->
+    true.
+
+next_state(State, _Res, {call, _Mod, _Fun, _Args}) ->
+    NewState = State,
+    NewState.
+