feat(rule): add testcase for '/delivery_dropped'

apps/emqx_rule_engine/test/emqx_rule_engine_SUITE.erl

@@ -144,6 +144,7 @@ init_per_testcase(t_events, Config) ->
                         "\"$events/message_acked\", "
                         "\"$events/message_delivered\", "
                         "\"$events/message_dropped\", "
+                        "\"$events/delivery_dropped\", "
                         "\"t1\"",
     {ok, Rule} = emqx_rule_engine:create_rule(
         #{id => <<"rule:t_events">>,
@@ -322,18 +323,20 @@ t_events(_Config) ->
         ]),
     ct:pal("====== verify $events/client_connected"),
     client_connected(Client, Client2),
+    ct:pal("====== verify $events/message_dropped"),
+    message_dropped(Client),
     ct:pal("====== verify $events/session_subscribed"),
     session_subscribed(Client2),
     ct:pal("====== verify t1"),
     message_publish(Client),
+    ct:pal("====== verify $events/delivery_dropped"),
+    delivery_dropped(Client),
     ct:pal("====== verify $events/message_delivered"),
     message_delivered(Client),
     ct:pal("====== verify $events/message_acked"),
     message_acked(Client),
     ct:pal("====== verify $events/session_unsubscribed"),
     session_unsubscribed(Client2),
-    ct:pal("====== verify $events/message_dropped"),
-    message_dropped(Client),
     ct:pal("====== verify $events/client_disconnected"),
     client_disconnected(Client, Client2),
     ok.
@@ -365,6 +368,15 @@ session_unsubscribed(Client2) ->
 message_delivered(_Client) ->
     verify_event('message.delivered'),
     ok.
+delivery_dropped(Client) ->
+    %% subscribe "t1" and then publish to "t1", the message will not be received by itself
+    %% because we have set the subscribe flag 'nl' = true
+    {ok, _, _} = emqtt:subscribe(Client, #{}, <<"t1">>, [{nl, true}, {qos, 1}]),
+    ct:sleep(50),
+    message_publish(Client),
+    ct:pal("--- current emqx hooks: ~p", [ets:tab2list(emqx_hooks)]),
+    verify_event('delivery.dropped'),
+    ok.
 message_dropped(Client) ->
     message_publish(Client),
     verify_event('message.dropped'),
@@ -1490,6 +1502,45 @@ verify_event_fields(SubUnsub, Fields) when SubUnsub == 'session.subscribed'
                  maps:get(PropKey, Fields)),
     ?assert(0 =< TimestampElapse andalso TimestampElapse =< 60*1000);
 
+verify_event_fields('delivery.dropped', Fields) ->
+    #{event := 'delivery.dropped',
+      id := ID,
+      metadata := #{rule_id := RuleId},
+      reason := Reason,
+      clientid := ClientId,
+      username := Username,
+      from_clientid := FromClientId,
+      from_username := FromUsername,
+      node := Node,
+      payload := Payload,
+      peerhost := PeerHost,
+      pub_props := Properties,
+      publish_received_at := EventAt,
+      qos := QoS,
+      flags := Flags,
+      timestamp := Timestamp,
+      topic := Topic} = Fields,
+    Now = erlang:system_time(millisecond),
+    TimestampElapse = Now - Timestamp,
+    RcvdAtElapse = Now - EventAt,
+    ?assert(is_binary(ID)),
+    ?assertEqual(<<"rule:t_events">>, RuleId),
+    ?assertEqual(no_local, Reason),
+    ?assertEqual(node(), Node),
+    ?assertEqual(<<"c_event">>, ClientId),
+    ?assertEqual(<<"u_event">>, Username),
+    ?assertEqual(<<"c_event">>, FromClientId),
+    ?assertEqual(<<"u_event">>, FromUsername),
+    ?assertEqual(<<"{\"id\": 1, \"name\": \"ha\"}">>, Payload),
+    verify_ipaddr(PeerHost),
+    ?assertEqual(<<"t1">>, Topic),
+    ?assertEqual(1, QoS),
+    ?assert(is_map(Flags)),
+    ?assertMatch(#{'Message-Expiry-Interval' := 60}, Properties),
+    ?assert(0 =< TimestampElapse andalso TimestampElapse =< 60*1000),
+    ?assert(0 =< RcvdAtElapse andalso RcvdAtElapse =< 60*1000),
+    ?assert(EventAt =< Timestamp);
+
 verify_event_fields('message.dropped', Fields) ->
     #{id := ID,
       reason := Reason,