Add the disconnect event callback

4 files changed, 42 insertions, 4 deletions

diff --git a/src/gun.erl b/src/gun.erl
index e958d2e..44dbdeb 100644
--- a/src/gun.erl
+++ b/src/gun.erl
@@ -1006,7 +1006,8 @@ commands([{switch_protocol, Protocol, _ProtoState0}|Tail],
 
 disconnect(State=#state{owner=Owner, opts=Opts,
 		socket=Socket, transport=Transport,
-		protocol=Protocol, protocol_state=ProtoState}, Reason) ->
+		protocol=Protocol, protocol_state=ProtoState,
+		event_handler=EventHandler, event_handler_state=EventHandlerState0}, Reason) ->
 	Protocol:close(Reason, ProtoState),
 	%% @todo Need a special state for orderly shutdown of a connection.
 	Transport:close(Socket),
@@ -1015,14 +1016,20 @@ disconnect(State=#state{owner=Owner, opts=Opts,
 	%% @todo Stop keepalive timeout, flush message.
 	{KilledStreams, UnprocessedStreams} = Protocol:down(ProtoState),
 	Owner ! {gun_down, self(), Protocol:name(), Reason, KilledStreams, UnprocessedStreams},
+	%% Trigger the disconnect event.
+	DisconnectEvent = #{
+		reason => Reason
+	},
+	EventHandlerState = EventHandler:disconnect(DisconnectEvent, EventHandlerState0),
 	Retry = maps:get(retry, Opts, 5),
 	case Retry of
 		0 ->
-			{stop, {shutdown, Reason}};
+			{stop, {shutdown, Reason}, State#state{event_handler_state=EventHandlerState}};
 		_ ->
 			{next_state, not_connected,
 				keepalive_cancel(State#state{socket=undefined,
-					protocol=undefined, protocol_state=undefined}),
+					protocol=undefined, protocol_state=undefined,
+					event_handler_state=EventHandlerState}),
 				{next_event, internal, {retries, Retry - 1}}}
 	end.
 
diff --git a/src/gun_default_event_h.erl b/src/gun_default_event_h.erl
index e242e84..f234dda 100644
--- a/src/gun_default_event_h.erl
+++ b/src/gun_default_event_h.erl
@@ -18,6 +18,7 @@
 -export([init/2]).
 -export([connect_start/2]).
 -export([connect_end/2]).
+-export([disconnect/2]).
 
 init(_EventData, State) ->
 	State.
@@ -27,3 +28,6 @@ connect_start(_EventData, State) ->
 
 connect_end(_EventData, State) ->
 	State.
+
+disconnect(_EventData, State) ->
+	State.
diff --git a/src/gun_event.erl b/src/gun_event.erl
index fffcafe..bb541ed 100644
--- a/src/gun_event.erl
+++ b/src/gun_event.erl
@@ -43,6 +43,14 @@
 -callback connect_start(connect_event(), State) -> State.
 -callback connect_end(connect_event(), State) -> State.
 
+%% disconnect.
+
+-type disconnect_event() :: #{
+	reason := normal | closed | {error, any()}
+}.
+
+-callback disconnect(disconnect_event(), State) -> State.
+
 %% @todo domain_lookup_start
 %% @todo domain_lookup_end
 %% @todo tls_handshake_start
@@ -50,7 +58,6 @@
 %% @todo origin_changed
 %% @todo transport_changed
 %% @todo protocol_changed
-%% @todo disconnected
 %% @todo terminate
 %% @todo stream_start
 %% @todo stream_end
diff --git a/test/event_SUITE.erl b/test/event_SUITE.erl
index 383ac46..50a1ce2 100644
--- a/test/event_SUITE.erl
+++ b/test/event_SUITE.erl
@@ -20,6 +20,7 @@
 
 -import(ct_helper, [config/2]).
 -import(ct_helper, [doc/1]).
+-import(gun_test, [init_origin/1]).
 
 all() ->
 	ct_helper:all(?MODULE).
@@ -99,6 +100,21 @@ connect_end_ok(Config) ->
 	} = do_receive_event(connect_end),
 	gun:close(Pid).
 
+disconnect(_) ->
+	doc("Confirm that the disconnect event callback is called on disconnect."),
+	Self = self(),
+	Opts = #{event_handler => {?MODULE, Self}},
+	{ok, OriginPid, OriginPort} = init_origin(tcp),
+	{ok, Pid} = gun:open("localhost", OriginPort, Opts),
+	{ok, http} = gun:await_up(Pid),
+	%% We make the origin exit to trigger a disconnect.
+	unlink(OriginPid),
+	exit(OriginPid, shutdown),
+	#{
+		reason := closed
+	} = do_receive_event(disconnect),
+	gun:close(Pid).
+
 %% Internal.
 
 do_receive_event(Event) ->
@@ -122,3 +138,7 @@ connect_start(EventData, Pid) ->
 connect_end(EventData, Pid) ->
 	Pid ! {?FUNCTION_NAME, EventData},
 	Pid.
+
+disconnect(EventData, Pid) ->
+	Pid ! {?FUNCTION_NAME, EventData},
+	Pid.