eLog/test/zzzz_gh280_crash.erl

%% @doc This test is named zzzz_gh280_crash because it has to be run first and tests are run in 
%% reverse alphabetical order.
%%
%% The problem we are attempting to detect here is when log_mf_h is installed as a handler for error_logger
%% and lager starts up to replace the current handlers with its own.  This causes a start up crash because
%% OTP error logging modules do not have any notion of a lager-style log level.
-module(zzzz_gh280_crash).

-include_lib("eunit/include/eunit.hrl").

gh280_crash_test() ->
   {timeout, 30, fun() -> gh280_impl() end}.

gh280_impl() ->
   application:stop(lager),
   application:stop(goldrush),

   error_logger:tty(false),
   %% see https://github.com/erlang/otp/blob/maint/lib/stdlib/src/log_mf_h.erl#L81
   %% for an explanation of the init arguments to log_mf_h
   ok = gen_event:add_sup_handler(error_logger, log_mf_h, log_mf_h:init("/tmp", 10000, 5)),
   eRum:start(),
   Result = receive
               {gen_event_EXIT, log_mf_h, normal} ->
                  true;
               {gen_event_EXIT, Handler, Reason} ->
                  {Handler, Reason};
               X ->
                  X
            after 10000 ->
         timeout
            end,
   ?assert(Result),
   application:stop(lager),
   application:stop(goldrush).