test: fix test case flakyness

apps/emqx_auth/src/emqx_authn/emqx_authn_chains.erl

@@ -353,13 +353,13 @@ init(_Opts) ->
     ok = emqx_config_handler:add_handler([listeners, '?', '?', ?CONF_ROOT], Module),
     ok = hook_deny(),
     {ok, #{hooked => false, providers => #{}, init_done => false},
-        {continue, initialize_authentication}}.
+        {continue, {initialize_authentication, init}}}.
 
 handle_call(get_providers, _From, #{providers := Providers} = State) ->
     reply(Providers, State);
 handle_call(
     {register_providers, Providers},
-    _From,
+    From,
     #{providers := Reg0} = State
 ) ->
     case lists:filter(fun({T, _}) -> maps:is_key(T, Reg0) end, Providers) of
@@ -371,7 +371,7 @@ handle_call(
                 Reg0,
                 Providers
             ),
-            reply(ok, State#{providers := Reg}, initialize_authentication);
+            reply(ok, State#{providers := Reg}, {initialize_authentication, From});
         Clashes ->
             reply({error, {authentication_type_clash, Clashes}}, State)
     end;
@@ -447,10 +447,10 @@ handle_call(Req, _From, State) ->
     ?SLOG(error, #{msg => "unexpected_call", call => Req}),
     {reply, ignored, State}.
 
-handle_continue(initialize_authentication, #{init_done := true} = State) ->
+handle_continue({initialize_authentication, _From}, #{init_done := true} = State) ->
     {noreply, State};
-handle_continue(initialize_authentication, #{providers := Providers} = State) ->
-    InitDone = initialize_authentication(Providers),
+handle_continue({initialize_authentication, From}, #{providers := Providers} = State) ->
+    InitDone = initialize_authentication(Providers, From),
     {noreply, maybe_hook(State#{init_done := InitDone})}.
 
 handle_cast(Req, State) ->
@@ -484,11 +484,13 @@ code_change(_OldVsn, State, _Extra) ->
 %% Private functions
 %%------------------------------------------------------------------------------
 
-initialize_authentication(Providers) ->
+initialize_authentication(Providers, From) ->
     ProviderTypes = maps:keys(Providers),
     Chains = chain_configs(),
     HasProviders = has_providers_for_configs(Chains, ProviderTypes),
-    do_initialize_authentication(Providers, Chains, HasProviders).
+    Result = do_initialize_authentication(Providers, Chains, HasProviders),
+    ?tp(info, authn_chains_initialization_done, #{from => From, result => Result}),
+    Result.
 
 do_initialize_authentication(_Providers, _Chains, _HasProviders = false) ->
     false;
@@ -500,7 +502,6 @@ do_initialize_authentication(Providers, Chains, _HasProviders = true) ->
         Chains
     ),
     ok = unhook_deny(),
-    ?tp(info, authn_chains_initialization_done, #{}),
     true.
 
 initialize_chain_authentication(_Providers, _ChainName, []) ->

apps/emqx_auth/test/emqx_authn/emqx_authn_init_SUITE.erl

@@ -69,9 +69,10 @@ t_initialize(_Config) ->
         emqx_access_control:authenticate(?CLIENTINFO)
     ),
 
+    Self = self(),
     ?assertWaitEvent(
         ok = emqx_authn_test_lib:register_fake_providers([{password_based, built_in_database}]),
-        #{?snk_kind := authn_chains_initialization_done},
+        #{?snk_kind := authn_chains_initialization_done, from := {Self, _}},
         100
     ),