diff --git a/src/lager_common_test_backend.erl b/src/lager_common_test_backend.erl new file mode 100644 index 0000000..9ed0dfc --- /dev/null +++ b/src/lager_common_test_backend.erl @@ -0,0 +1,115 @@ +-module(lager_common_test_backend). + +-behavior(gen_event). + +%% gen_event callbacks +-export([init/1, + handle_call/2, + handle_event/2, + handle_info/2, + terminate/2, + code_change/3]). +-export([get_logs/0, + bounce/0, + bounce/1]). + +%% holds the log messages for retreival on terminate +-record(state, {level :: {mask, integer()}, + formatter :: atom(), + format_config :: any(), + log = [] :: list()}). + +-include("lager.hrl"). +-define(TERSE_FORMAT,[time, " ", color, "[", severity,"] ", message]). + +%% @doc Before every test, just +%% lager_common_test_backend:bounce(Level) with the log level of your +%% choice. Every message will be passed along to ct:pal for your +%% viewing in the common_test reports. Also, you can call +%% lager_common_test_backend:get_logs/0 to get a list of all log +%% messages this backend has received during your test. You can then +%% search that list for expected log messages. + + +-spec get_logs() -> [iolist()] | {error, term()}. +get_logs() -> + gen_event:call(lager_event, ?MODULE, get_logs, infinity). + +bounce() -> + bounce(error). + +bounce(Level) -> + application:stop(lager), + lager:start(), + gen_event:add_handler(lager_event, lager_common_test_backend, [Level, false]), + %lager:set_loglevel(lager_common_test_backend, Level), + ok. + +-spec(init(integer()|atom()|[term()]) -> {ok, #state{}} | {error, atom()}). +%% @private +%% @doc Initializes the event handler +init([Level, true]) -> % for backwards compatibility + init([Level,{lager_default_formatter,[{eol, "\n"}]}]); +init([Level,false]) -> % for backwards compatibility + init([Level,{lager_default_formatter,?TERSE_FORMAT ++ ["\n"]}]); +init([Level,{Formatter,FormatterConfig}]) when is_atom(Formatter) -> + case lists:member(Level, ?LEVELS) of + true -> + {ok, #state{level=lager_util:config_to_mask(Level), + formatter=Formatter, + format_config=FormatterConfig}}; + _ -> + {error, bad_log_level} + end; +init(Level) -> + init([Level,{lager_default_formatter,?TERSE_FORMAT ++ ["\n"]}]). + +-spec(handle_event(tuple(), #state{}) -> {ok, #state{}}). +%% @private +handle_event({log, Message}, + #state{level=L,formatter=Formatter,format_config=FormatConfig,log=Logs} = State) -> + case lager_util:is_loggable(Message,L,?MODULE) of + true -> + Log = Formatter:format(Message,FormatConfig), + ct:pal(Log), + {ok, State#state{log=[Log|Logs]}}; + false -> + {ok, State} + end; +handle_event(Event, State) -> + ct:pal(Event), + {ok, State#state{log = [Event|State#state.log]}}. + +-spec(handle_call(any(), #state{}) -> {ok, any(), #state{}}). +%% @private +%% @doc gets and sets loglevel. This is part of the lager backend api. +handle_call(get_loglevel, #state{level=Level} = State) -> + {ok, Level, State}; +handle_call({set_loglevel, Level}, State) -> + case lists:member(Level, ?LEVELS) of + true -> + {ok, ok, State#state{level=lager_util:level_to_num(Level)}}; + _ -> + {ok, {error, bad_log_level}, State} + end; +handle_call(get_logs, #state{log = Logs} = State) -> + {ok, lists:reverse(Logs), State}; +handle_call(_, State) -> + {ok, ok, State}. + +-spec(handle_info(any(), #state{}) -> {ok, #state{}}). +%% @private +%% @doc gen_event callback, does nothing. +handle_info(_, State) -> + {ok, State}. + +-spec(code_change(any(), #state{}, any()) -> {ok, #state{}}). +%% @private +%% @doc gen_event callback, does nothing. +code_change(_OldVsn, State, _Extra) -> + {ok, State}. + +-spec(terminate(any(), #state{}) -> {ok, list()}). +%% @doc gen_event callback, does nothing. +terminate(_Reason, #state{log=Logs}) -> + {ok, lists:reverse(Logs)}.