chore(authn): improve code of moving authenticator

apps/emqx/src/emqx_authentication.erl

@@ -78,6 +78,14 @@
 -define(VER_1, <<"1">>).
 -define(VER_2, <<"2">>).
 
+-type chain_name() :: atom().
+-type authenticator_id() :: binary().
+-type position() :: top | bottom | {before, authenticator_id()}.
+-type update_request() :: {create_authenticator, chain_name(), map()}
+                        | {delete_authenticator, chain_name(), authenticator_id()}
+                        | {update_authenticator, chain_name(), authenticator_id(), map()}
+                        | {move_authenitcator, chain_name(), authenticator_id(), position()}.
+
 -type config() :: #{atom() => term()}.
 -type state() :: #{atom() => term()}.
 -type extra() :: #{is_superuser := boolean(),
@@ -159,6 +167,8 @@ authentication(_) -> undefined.
 %% Callbacks of config handler
 %%------------------------------------------------------------------------------
 
+-spec pre_config_update(update_request(), emqx_config:raw_config())
+    -> {ok, map() | list()} | {error, term()}.
 pre_config_update(UpdateReq, OldConfig) ->
     case do_pre_config_update(UpdateReq, to_list(OldConfig)) of
         {error, Reason} -> {error, Reason};
@@ -185,22 +195,22 @@ do_pre_config_update({move_authenticator, _ChainName, AuthenticatorID, Position}
         {error, Reason} -> {error, Reason};
         {ok, Part1, [Found | Part2]} ->
             case Position of
-                <<"top">> ->
+                top ->
                     {ok, [Found | Part1] ++ Part2};
-                <<"bottom">> ->
+                bottom ->
                     {ok, Part1 ++ Part2 ++ [Found]};
-                <<"before:", Before/binary>> ->
+                {before, Before} ->
                     case split_by_id(Before, Part1 ++ Part2) of
                         {error, Reason} ->
                             {error, Reason};
                         {ok, NPart1, [NFound | NPart2]} ->
                             {ok, NPart1 ++ [Found, NFound | NPart2]}
-                    end;
-                _ ->
-                    {error, {invalid_parameter, position}}
+                    end
             end
     end.
 
+-spec post_config_update(update_request, map() | list(), emqx_config:raw_config(), emqx_config:app_envs())
+    -> ok | {ok, map()} | {error, term()}.
 post_config_update(UpdateReq, NewConfig, OldConfig, AppEnvs) ->
     do_post_config_update(UpdateReq, check_config(to_list(NewConfig)), OldConfig, AppEnvs).
 
@@ -220,13 +230,7 @@ do_post_config_update({update_authenticator, ChainName, AuthenticatorID, _Config
     update_authenticator(ChainName, AuthenticatorID, NConfig);
 
 do_post_config_update({move_authenticator, ChainName, AuthenticatorID, Position}, _NewConfig, _OldConfig, _AppEnvs) ->
-    NPosition = case Position of
-                    <<"top">> -> top;
-                    <<"bottom">> -> bottom;
-                    <<"before:", Before/binary>> ->
-                        {before, Before}
-                end,
-    move_authenticator(ChainName, AuthenticatorID, NPosition).
+    move_authenticator(ChainName, AuthenticatorID, Position).
 
 check_config(Config) ->
     #{authentication := CheckedConfig} = hocon_schema:check_plain(emqx_authentication,

apps/emqx_authn/src/emqx_authn_api.erl

@@ -1877,10 +1877,15 @@ delete_authenticator(ConfKeyPath, ChainName0, AuthenticatorID) ->
 
 move_authenitcator(ConfKeyPath, ChainName0, AuthenticatorID, Position) ->
     ChainName = to_atom(ChainName0),
-    case update_config(ConfKeyPath, {move_authenticator, ChainName, AuthenticatorID, Position}) of
-        {ok, _} ->
-            {204};
-        {error, {_, _, Reason}} ->
+    case parse_position(Position) of
+        {ok, NPosition} ->
+            case update_config(ConfKeyPath, {move_authenticator, ChainName, AuthenticatorID, NPosition}) of
+                {ok, _} ->
+                    {204};
+                {error, {_, _, Reason}} ->
+                    serialize_error(Reason)
+            end;
+        {error, Reason} ->
             serialize_error(Reason)
     end.
 
@@ -2016,6 +2021,15 @@ serialize_error(Reason) ->
     {400, #{code => <<"BAD_REQUEST">>,
             message => list_to_binary(io_lib:format("~p", [Reason]))}}.
 
+parse_position(<<"top">>) ->
+    {ok, top};
+parse_position(<<"bottom">>) ->
+    {ok, bottom};
+parse_position(<<"before:", Before/binary>>) ->
+    {ok, {before, Before}};
+parse_position(_) ->
+    {error, {invalid_parameter, position}}.
+
 to_list(M) when is_map(M) ->
     [M];
 to_list(L) when is_list(L) ->