test(gw): eliminate side effect between tests

apps/emqx_gateway/src/emqx_gateway_conf.erl

@@ -365,7 +365,7 @@ pre_config_update(UnknownReq, _RawConf) ->
                          emqx_config:config(), emqx_config:app_envs())
     -> ok | {ok, Result::any()} | {error, Reason::term()}.
 
-post_config_update(Req, NewConfig, OldConfig, _AppEnvs) ->
+post_config_update(Req, NewConfig, OldConfig, _AppEnvs) when is_tuple(Req) ->
     [_Tag, GwName0|_] = tuple_to_list(Req),
     GwName = binary_to_existing_atom(GwName0),
 
@@ -379,4 +379,6 @@ post_config_update(Req, NewConfig, OldConfig, _AppEnvs) ->
             emqx_gateway:load(GwName, New);
         {New, Old} when is_map(New), is_map(Old) ->
             emqx_gateway:update(GwName, New)
-    end.
+    end;
+post_config_update(_Req, _NewConfig, _OldConfig, _AppEnvs) ->
+    ok.

apps/emqx_gateway/test/emqx_coap_SUITE.erl

@@ -58,6 +58,7 @@ set_special_cfg(_) ->
     ok.
 
 end_per_suite(Config) ->
+    {ok, _} = emqx:remove_config([<<"gateway">>,<<"coap">>]),
     emqx_common_test_helpers:stop_apps([emqx_gateway]),
     Config.
 

apps/emqx_gateway/test/emqx_exproto_SUITE.erl

@@ -60,6 +60,7 @@ init_per_group(GrpName, Cfg) ->
     [{servers, Svrs}, {listener_type, GrpName} | Cfg].
 
 end_per_group(_, Cfg) ->
+    {ok, _} = emqx:remove_config([gateway, exproto]),
     emqx_common_test_helpers:stop_apps([emqx_gateway]),
     emqx_exproto_echo_svr:stop(proplists:get_value(servers, Cfg)).
 

apps/emqx_gateway/test/emqx_sn_protocol_SUITE.erl

@@ -87,6 +87,7 @@ init_per_suite(Config) ->
     Config.
 
 end_per_suite(_) ->
+    {ok, _} = emqx:remove_config([gateway, mqttsn]),
     emqx_common_test_helpers:stop_apps([emqx_gateway]).
 
 %%--------------------------------------------------------------------