[logger] Add handler callback filter_config/1

This function is called when a logger API function for fetching
handler configuration is called. The point is to allow the handler to
remove internal data fields that it might have stored in the
configuration database, before returning the handler configuration to
the caller.

An example of such internal data are the 'handler_pid' and 'mode_tab'
fields that logger_std_h and logger_disk_log_h store in their
configuration maps.

2 files changed, 30 insertions, 0 deletions

diff --git a/lib/kernel/test/logger_disk_log_h_SUITE.erl b/lib/kernel/test/logger_disk_log_h_SUITE.erl
index 34f1969e67..905c2c52c5 100644
--- a/lib/kernel/test/logger_disk_log_h_SUITE.erl
+++ b/lib/kernel/test/logger_disk_log_h_SUITE.erl
@@ -92,6 +92,7 @@ all() ->
      disk_log_opts,
      default_formatter,
      logging,
+     filter_config,
      errors,
      formatter_fail,
      config_fail,
@@ -302,6 +303,20 @@ logging(cleanup, _Config) ->
     Name = list_to_atom(lists:concat([?FUNCTION_NAME,"_1"])),
     remove_and_stop(Name).
 
+filter_config(_Config) ->
+    ok = logger:add_handler(?MODULE,logger_disk_log_h,#{}),
+    {ok,#{config:=HConfig}=Config} = logger:get_handler_config(?MODULE),
+    HConfig = maps:without([handler_pid,mode_tab],HConfig),
+
+    FakeFullHConfig = HConfig#{handler_pid=>self(),mode_tab=>erlang:make_ref()},
+    #{config:=HConfig} =
+        logger_disk_log_h:filter_config(Config#{config=>FakeFullHConfig}),
+    ok.
+
+filter_config(cleanup,_Config) ->
+    logger:remove_handler(?MODULE),
+    ok.
+
 errors(Config) ->
     PrivDir = ?config(priv_dir,Config),
     Name1 = list_to_atom(lists:concat([?FUNCTION_NAME,"_1"])),
diff --git a/lib/kernel/test/logger_std_h_SUITE.erl b/lib/kernel/test/logger_std_h_SUITE.erl
index c5d742ea7f..b6a09f4980 100644
--- a/lib/kernel/test/logger_std_h_SUITE.erl
+++ b/lib/kernel/test/logger_std_h_SUITE.erl
@@ -108,6 +108,7 @@ all() ->
      add_remove_instance_file1,
      add_remove_instance_file2,
      default_formatter,
+     filter_config,
      errors,
      formatter_fail,
      config_fail,
@@ -204,6 +205,20 @@ default_formatter(_Config) ->
     match = re:run(Msg,"=NOTICE REPORT====.*\n"++M1,[{capture,none}]),
     ok.
 
+filter_config(_Config) ->
+    ok = logger:add_handler(?MODULE,logger_std_h,#{}),
+    {ok,#{config:=HConfig}=Config} = logger:get_handler_config(?MODULE),
+    HConfig = maps:without([handler_pid,mode_tab],HConfig),
+
+    FakeFullHConfig = HConfig#{handler_pid=>self(),mode_tab=>erlang:make_ref()},
+    #{config:=HConfig} =
+        logger_std_h:filter_config(Config#{config=>FakeFullHConfig}),
+    ok.
+
+filter_config(cleanup,_Config) ->
+    logger:remove_handler(?MODULE),
+    ok.
+
 errors(Config) ->
     Dir = ?config(priv_dir,Config),
     Log = filename:join(Dir,?FUNCTION_NAME),