test(exhook): remove helpless test case

apps/emqx/src/emqx_sys.erl

@@ -112,7 +112,7 @@ sys_interval() ->
 sys_heatbeat_interval() ->
     emqx:get_config([sys_topics, sys_heartbeat_interval]).
 
-sys_event_message() ->
+sys_event_messages() ->
     emqx:get_config([sys_topics, sys_event_messages]).
 
 %% @doc Get sys info
@@ -143,7 +143,7 @@ load_event_hooks() ->
          ({K, true}) ->
             {HookPoint, Fun} = hook_and_fun(K),
             emqx_hooks:put(HookPoint, {?MODULE, Fun, []})
-      end, maps:to_list(sys_event_message())).
+      end, maps:to_list(sys_event_messages())).
 
 handle_call(Req, _From, State) ->
     ?SLOG(error, #{msg => "unexpected_call", call => Req}),
@@ -178,7 +178,7 @@ unload_event_hooks() ->
     lists:foreach(fun({K, _}) ->
         {HookPoint, Fun} = hook_and_fun(K),
         emqx_hooks:del(HookPoint, {?MODULE, Fun})
-    end, maps:to_list(sys_event_message())).
+    end, maps:to_list(sys_event_messages())).
 
 %%--------------------------------------------------------------------
 %% hook callbacks

apps/emqx_exhook/test/emqx_exhook_SUITE.erl

@@ -24,12 +24,6 @@
 -define(CLUSTER_RPC_SHARD, emqx_cluster_rpc_shard).
 
 -define(CONF_DEFAULT, <<"
-sys_topics {
-  sys_event_messages {
-    client_connected = false
-    client_disconnected = false
-  }
-}
 exhook {
   servers = [
     { name = default,
@@ -96,12 +90,6 @@ end_per_testcase(_, Config) ->
 %% Test cases
 %%--------------------------------------------------------------------
 
-t_noserver_nohook(_) ->
-    emqx_exhook_mgr:disable(<<"default">>),
-    ?assertEqual([], ets:tab2list(emqx_hooks)),
-    {ok, _} = emqx_exhook_mgr:enable(<<"default">>),
-    ?assertNotEqual([], ets:tab2list(emqx_hooks)).
-
 t_access_failed_if_no_server_running(_) ->
     emqx_exhook_mgr:disable(<<"default">>),
     ClientInfo = #{clientid => <<"user-id-1">>,