Fix default topic exchange stomp test

The exchange setting  is frozen per connection so it must be set before client connects.
Also add indirect check set exchange is actually used. We check new binding was added after SUBSCRIBE frame.
TODO: currently  accepts any exchange type, fix that.

(cherry picked from commit ad5241f)
(cherry picked from commit 3506b1c)

Author: deadtrickster

deps/rabbitmq_stomp/test/topic_SUITE.erl

@@ -137,18 +137,23 @@ subscribe_topic_authorisation(Config) ->
 
 change_default_topic_exchange(Config) ->
     Channel = ?config(amqp_channel, Config),
-    ClientFoo = ?config(client_foo, Config),
+    Version = ?config(version, Config),
+    StompPort = rabbit_ct_broker_helpers:get_node_config(Config, 0, tcp_port_stomp),
     Ex = <<"my-topic-exchange">>,
+    ok = rabbit_ct_broker_helpers:rpc(Config, 0, application, set_env, [rabbitmq_stomp, default_topic_exchange, Ex]),
+    {ok, ClientFoo} = rabbit_stomp_client:connect(Version, StompPort),
     AuthorisedTopic = "/topic/user.AuthorisedTopic",
 
     Declare = #'exchange.declare'{exchange = Ex, type = <<"topic">>},
     #'exchange.declare_ok'{} = amqp_channel:call(Channel, Declare),
 
-    ok = rabbit_ct_broker_helpers:rpc(Config, 0, application, set_env, [rabbitmq_stomp, default_topic_exchange, Ex]),
+    0 = length(rabbit_ct_broker_helpers:rpc(Config, 0, rabbit_binding, list_for_source, [#resource{virtual_host= <<"/">>, kind = exchange, name = Ex}])),
 
     rabbit_stomp_client:send(
         ClientFoo, "SUBSCRIBE", [{"destination", AuthorisedTopic}]),
 
+    1 = length(rabbit_ct_broker_helpers:rpc(Config, 0, rabbit_binding, list_for_source, [#resource{virtual_host= <<"/">>, kind = exchange, name = Ex}])),
+
     rabbit_stomp_client:send(
         ClientFoo, "SEND", [{"destination", AuthorisedTopic}], ["ohai there"]),
 
@@ -158,6 +163,7 @@ change_default_topic_exchange(Config) ->
     Delete = #'exchange.delete'{exchange = Ex},
     #'exchange.delete_ok'{} = amqp_channel:call(Channel, Delete),
     ok = rabbit_ct_broker_helpers:rpc(Config, 0, application, unset_env, [rabbitmq_stomp, default_topic_exchange]),
+    rabbit_stomp_client:disconnect(ClientFoo),
     ok.