feat: make quicer:listener/1 don't crash when listener not found

emqx · Apr 20, 2022 · ff55d12 · ff55d12
1 parent 8950d3a
commit ff55d12
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Showing 3 changed files with 16 additions and 7 deletions.
diff --git a/src/quicer.erl b/src/quicer.erl
@@ -551,7 +551,7 @@ listeners() ->
 
 -spec listener(quicer_listener:listener_name()
               | {quicer_listener:listener_name(),
-                 quicer_listener:listen_on()}) -> pid().
+                 quicer_listener:listen_on()}) -> {ok, pid()} | {error, not_found}.
 listener(Name) ->
   quicer_listener_sup:listener(Name).
 

diff --git a/src/quicer_listener_sup.erl b/src/quicer_listener_sup.erl
@@ -68,16 +68,19 @@ listeners() ->
               end
       end, supervisor:which_children(?MODULE)).
 
--spec listener(atom() | {atom(), integer()|string()}) -> pid().
+-spec listener(atom() | {atom(), integer()|string()}) -> {ok, pid()}|{error, not_found}.
 listener({Name, _ListenOn}) when is_atom(Name) ->
     listener(Name);
 listener(Name) when is_atom(Name) ->
-    [Target] = lists:filtermap(
+    Targets = lists:filtermap(
                  fun({?CHILD_ID(Id), Child, _Type, _Modules}) when Id =:= Name ->
                          {true, Child};
                     (_) -> false
                  end, supervisor:which_children(?MODULE)),
-    Target.
+    case Targets of
+      [Pid] -> {ok, Pid};
+      [] -> {error, not_found}
+   end.
 
 %%%===================================================================
 %%% Supervisor callbacks

diff --git a/test/quicer_SUITE.erl b/test/quicer_SUITE.erl
@@ -300,12 +300,18 @@ tc_get_listener(Config) ->
             end, Listeners),
 
   lists:foreach(fun({Name, _} = NameListenON) ->
-                    LPid = quicer:listener(Name),
-                    LPid = quicer:listener(NameListenON),
+                    {ok, LPid} = quicer:listener(Name),
+                    {ok, LPid} = quicer:listener(NameListenON),
                     true = is_process_alive(LPid)
                 end, Listeners),
 
-  lists:foreach(fun({L, _}) -> ok = quicer:stop_listener(L) end, Listeners).
+  lists:foreach(fun({L, _}) -> ok = quicer:stop_listener(L) end, Listeners),
+
+  lists:foreach(fun({Name, _} = NameListenON) ->
+                    ?assertEqual({error, not_found}, quicer:listener(Name)),
+                    ?assertEqual({error, not_found}, quicer:listener(NameListenON))
+                end, Listeners),
+  ?assertEqual({error, not_found}, quicer:listener(bad_listen_name)).
 
 tc_conn_basic(Config)->
   Port = select_port(),