lager/test/crash_statem.erl

-module(crash_statem).
%% we're only going to compile this on OTP 19+
-ifdef(test_statem).
-behaviour(gen_statem).

-export([
         start/0,
         crash/0,
         handle_event/4
]).

-export([terminate/3,code_change/4,init/1,callback_mode/0]).

start() ->
    gen_statem:start({local,?MODULE}, ?MODULE, [], []).

crash() ->
    gen_statem:call(?MODULE, boom).

%% Mandatory callback functions
terminate(_Reason, _State, _Data) -> ok.
code_change(_Vsn, State, Data, _Extra) -> {ok,State,Data}.
init([]) ->
    %% insert rant here about breaking changes in minor versions...
    case erlang:system_info(version) of
        "8.0" -> {callback_mode(),state1,undefined};
        _ -> {ok, state1, undefined}
    end.
callback_mode() -> handle_event_function.

%%% state callback(s)

handle_event({call, _From}, state1, _Arg, Data) ->
    {next_state, state1, Data}.

-else.
-export([start/0, crash/0]).

start() -> ok.
crash() -> ok.

-endif.