Increase test coverage for Direct Reply-to

Add more tests for the Direct Reply-to feature in AMQP 0.9.1.

This will help the future Direct Reply-To refactoring making sure the
existing behaviour won't break.

Author: ansd

deps/rabbit/test/amqpl_direct_reply_to_SUITE.erl

@@ -18,6 +18,9 @@
 
 -define(TIMEOUT, 30_000).
 
+%% This is the pseudo queue that is specially interpreted by RabbitMQ.
+-define(REPLY_QUEUE, <<"amq.rabbitmq.reply-to">>).
+
 all() ->
     [
      {group, cluster_size_1},
@@ -28,7 +31,11 @@ groups() ->
     [
      {cluster_size_1, [shuffle],
       [
-       trace
+       trace,
+       failure_ack_mode,
+       failure_multiple_consumers,
+       failure_reuse_consumer_tag,
+       failure_publish
       ]},
      {cluster_size_3, [shuffle],
       [
@@ -82,8 +89,6 @@ trace(Config) ->
     Node = atom_to_binary(rabbit_ct_broker_helpers:get_node_config(Config, 0, nodename)),
     TraceQueue = <<"tests.amqpl_direct_reply_to.trace.tracing">>,
     RequestQueue = <<"tests.amqpl_direct_reply_to.trace.requests">>,
-    %% This is the pseudo queue that is specially interpreted by RabbitMQ.
-    ReplyQueue = <<"amq.rabbitmq.reply-to">>,
     RequestPayload = <<"my request">>,
     ReplyPayload = <<"my reply">>,
     CorrelationId = <<"my correlation ID">>,
@@ -102,7 +107,7 @@ trace(Config) ->
 
     %% There is no need to declare this pseudo queue first.
     amqp_channel:subscribe(RequesterCh,
-                           #'basic.consume'{queue = ReplyQueue,
+                           #'basic.consume'{queue = ?REPLY_QUEUE,
                                             no_ack = true},
                            self()),
     CTag = receive #'basic.consume_ok'{consumer_tag = CTag0} -> CTag0
@@ -114,7 +119,7 @@ trace(Config) ->
     amqp_channel:cast(
       RequesterCh,
       #'basic.publish'{routing_key = RequestQueue},
-      #amqp_msg{props = #'P_basic'{reply_to = ReplyQueue,
+      #amqp_msg{props = #'P_basic'{reply_to = ?REPLY_QUEUE,
                                    correlation_id = CorrelationId},
                 payload = RequestPayload}),
     receive #'basic.ack'{} -> ok
@@ -182,6 +187,85 @@ trace(Config) ->
     [#'queue.delete_ok'{} = amqp_channel:call(Ch, #'queue.delete'{queue = Q0}) || Q0 <- Qs],
     {ok, _} = rabbit_ct_broker_helpers:rabbitmqctl(Config, 0, ["trace_off"]).
 
+%% A consumer must consume in no-ack mode.
+failure_ack_mode(Config) ->
+    {Conn, Ch} = rabbit_ct_client_helpers:open_connection_and_channel(Config),
+    Consume = #'basic.consume'{queue = ?REPLY_QUEUE,
+                               no_ack = false},
+    try amqp_channel:subscribe(Ch, Consume, self()) of
+        _ ->
+            ct:fail("expected subscribe in ack mode to fail")
+    catch exit:Reason ->
+              ?assertMatch(
+                 {{_, {_, _, <<"PRECONDITION_FAILED - reply consumer cannot acknowledge">>}}, _},
+                 Reason)
+    end,
+    ok = rabbit_ct_client_helpers:close_connection(Conn).
+
+%% In AMQP 0.9.1 there can be at most one reply consumer per channel.
+failure_multiple_consumers(Config) ->
+    {Conn, Ch} = rabbit_ct_client_helpers:open_connection_and_channel(Config),
+    Consume = #'basic.consume'{queue = ?REPLY_QUEUE,
+                               no_ack = true},
+    amqp_channel:subscribe(Ch, Consume, self()),
+    receive #'basic.consume_ok'{} -> ok
+    end,
+
+    try amqp_channel:subscribe(Ch, Consume, self()) of
+        _ ->
+            ct:fail("expected second subscribe to fail")
+    catch exit:Reason ->
+              ?assertMatch(
+                 {{_, {_, _, <<"PRECONDITION_FAILED - reply consumer already set">>}}, _},
+                 Reason)
+    end,
+    ok = rabbit_ct_client_helpers:close_connection(Conn).
+
+%% Reusing the same consumer tag should fail.
+failure_reuse_consumer_tag(Config) ->
+    {_, Ch} = rabbit_ct_client_helpers:open_connection_and_channel(Config),
+    Ctag = <<"my-tag">>,
+
+    #'queue.declare_ok'{queue = Q} = amqp_channel:call(Ch, #'queue.declare'{exclusive = true}),
+    amqp_channel:subscribe(Ch, #'basic.consume'{queue = Q,
+                                                consumer_tag = Ctag}, self()),
+    receive #'basic.consume_ok'{} -> ok
+    end,
+
+    try amqp_channel:subscribe(Ch, #'basic.consume'{queue = ?REPLY_QUEUE,
+                                                    consumer_tag = Ctag,
+                                                    no_ack = true}, self()) of
+        _ ->
+            ct:fail("expected reusing consumer tag to fail")
+    catch exit:Reason ->
+              ?assertMatch(
+                 {{_, {connection_closing,
+                       {_, _, <<"NOT_ALLOWED - attempt to reuse consumer tag 'my-tag'">>}
+                      }}, _},
+                 Reason)
+    end.
+
+%% Publishing with reply_to header set but without consuming from the pseudo queue should fail.
+failure_publish(Config) ->
+    {Conn, Ch} = rabbit_ct_client_helpers:open_connection_and_channel(Config),
+
+    Ref = monitor(process, Ch),
+    amqp_channel:cast(
+      Ch,
+      #'basic.publish'{routing_key = <<"some request queue">>},
+      #amqp_msg{props = #'P_basic'{reply_to = ?REPLY_QUEUE,
+                                   correlation_id = <<"some correlation ID">>},
+                payload = <<"some payload">>}),
+
+    receive {'DOWN', Ref, process, Ch, Reason} ->
+                ?assertMatch(
+                   {_, {_, _, <<"PRECONDITION_FAILED - fast reply consumer does not exist">>}},
+                   Reason)
+    after ?TIMEOUT ->
+              ct:fail("expected channel error")
+    end,
+    ok = rabbit_ct_client_helpers:close_connection(Conn).
+
 %% "new" and "old" refers to new and old RabbitMQ versions in mixed version tests.
 rpc_new_to_old_node(Config) ->
     rpc(0, 1, Config).
@@ -190,36 +274,40 @@ rpc_old_to_new_node(Config) ->
     rpc(1, 0, Config).
 
 rpc(RequesterNode, ResponderNode, Config) ->
-    RequestQueue = <<"tests.amqpl_direct_reply_to.rpc.requests">>,
-    %% This is the pseudo queue that is specially interpreted by RabbitMQ.
-    ReplyQueue = <<"amq.rabbitmq.reply-to">>,
+    RequestQueue = <<"request queue">>,
     RequestPayload = <<"my request">>,
-    ReplyPayload = <<"my reply">>,
     CorrelationId = <<"my correlation ID">>,
     RequesterCh = rabbit_ct_client_helpers:open_channel(Config, RequesterNode),
     ResponderCh = rabbit_ct_client_helpers:open_channel(Config, ResponderNode),
 
     %% There is no need to declare this pseudo queue first.
     amqp_channel:subscribe(RequesterCh,
-                           #'basic.consume'{queue = ReplyQueue,
+                           #'basic.consume'{queue = ?REPLY_QUEUE,
                                             no_ack = true},
                            self()),
     CTag = receive #'basic.consume_ok'{consumer_tag = CTag0} -> CTag0
            end,
+
+    ?assertEqual(#'queue.declare_ok'{queue = ?REPLY_QUEUE,
+                                     message_count = 0,
+                                     consumer_count = 1},
+                 amqp_channel:call(RequesterCh,
+                                   #'queue.declare'{queue = ?REPLY_QUEUE})),
+
     #'queue.declare_ok'{} = amqp_channel:call(
                               RequesterCh,
                               #'queue.declare'{queue = RequestQueue}),
     #'confirm.select_ok'{} = amqp_channel:call(RequesterCh, #'confirm.select'{}),
     amqp_channel:register_confirm_handler(RequesterCh, self()),
+
     %% Send the request.
     amqp_channel:cast(
       RequesterCh,
       #'basic.publish'{routing_key = RequestQueue},
-      #amqp_msg{props = #'P_basic'{reply_to = ReplyQueue,
+      #amqp_msg{props = #'P_basic'{reply_to = ?REPLY_QUEUE,
                                    correlation_id = CorrelationId},
                 payload = RequestPayload}),
     receive #'basic.ack'{} -> ok
-    after ?TIMEOUT -> ct:fail(confirm_timeout)
     end,
 
     ok = wait_for_queue_declared(RequestQueue, ResponderNode, Config),
@@ -229,20 +317,101 @@ rpc(RequesterNode, ResponderNode, Config) ->
                                   correlation_id = CorrelationId},
                payload = RequestPayload}
     } = amqp_channel:call(ResponderCh, #'basic.get'{queue = RequestQueue}),
+
+    %% Test what the docs state:
+    %% "If the RPC server is going to perform some expensive computation it might wish
+    %% to check if the client has gone away. To do this the server can declare the
+    %% generated reply name first on a disposable channel in order to determine whether
+    %% it still exists."
+    ?assertEqual(#'queue.declare_ok'{queue = ReplyTo,
+                                     message_count = 0,
+                                     consumer_count = 1},
+                 amqp_channel:call(ResponderCh,
+                                   #'queue.declare'{queue = ReplyTo})),
+
     %% Send the reply.
     amqp_channel:cast(
       ResponderCh,
       #'basic.publish'{routing_key = ReplyTo},
       #amqp_msg{props = #'P_basic'{correlation_id = CorrelationId},
-                payload = ReplyPayload}),
+                payload = <<"reply 1">>}),
 
-    %% Receive the reply.
+    %% Let's assume the RPC server sends multiple replies for a single request.
+    %% (This is a bit unusual but should work.)
+    amqp_channel:cast(
+      ResponderCh,
+      #'basic.publish'{routing_key = ReplyTo},
+      #amqp_msg{props = #'P_basic'{correlation_id = CorrelationId},
+                payload = <<"reply 2">>}),
+
+    %% Receive the frst reply.
+    receive {#'basic.deliver'{consumer_tag = CTag,
+                              redelivered = false,
+                              exchange = <<>>,
+                              routing_key = ReplyTo},
+             #amqp_msg{payload = P1,
+                       props = #'P_basic'{correlation_id = CorrelationId}}} ->
+                ?assertEqual(<<"reply 1">>, P1)
+    after ?TIMEOUT -> ct:fail({missing_reply, ?LINE})
+    end,
+
+    %% Receive the second reply.
     receive {#'basic.deliver'{consumer_tag = CTag},
-             #amqp_msg{payload = ReplyPayload,
+             #amqp_msg{payload = P2,
                        props = #'P_basic'{correlation_id = CorrelationId}}} ->
-                ok
-    after ?TIMEOUT -> ct:fail(missing_reply)
-    end.
+                ?assertEqual(<<"reply 2">>, P2)
+    after ?TIMEOUT -> ct:fail({missing_reply, ?LINE})
+    end,
+
+    %% The requester sends a reply to itself.
+    %% (Really odd, but should work.)
+    amqp_channel:cast(
+      RequesterCh,
+      #'basic.publish'{routing_key = ReplyTo},
+      #amqp_msg{props = #'P_basic'{correlation_id = CorrelationId},
+                payload = <<"reply 3">>}),
+
+    receive {#'basic.deliver'{consumer_tag = CTag},
+             #amqp_msg{payload = P3,
+                       props = #'P_basic'{correlation_id = CorrelationId}}} ->
+                ?assertEqual(<<"reply 3">>, P3)
+    after ?TIMEOUT -> ct:fail({missing_reply, ?LINE})
+    end,
+
+    %% Requester cancels consumption.
+    ?assertMatch(#'basic.cancel_ok'{consumer_tag = CTag},
+                 amqp_channel:call(RequesterCh, #'basic.cancel'{consumer_tag = CTag})),
+
+    %% Send a final reply.
+    amqp_channel:cast(
+      ResponderCh,
+      #'basic.publish'{routing_key = ReplyTo},
+      #amqp_msg{props = #'P_basic'{correlation_id = CorrelationId},
+                payload = <<"reply 4">>}),
+
+    %% The final reply shouldn't be delivered since the requester cancelled consumption.
+    receive {#'basic.deliver'{}, #amqp_msg{}} ->
+                ct:fail("did not expect delivery after cancellation")
+    after 100 -> ok
+    end,
+
+    %% Responder checks again if the requester is still there.
+    %% This time, the requester and its queue should be gone.
+    try amqp_channel:call(ResponderCh, #'queue.declare'{queue = ReplyTo}) of
+        _ ->
+            ct:fail("expected queue.declare to fail")
+    catch exit:Reason ->
+              ?assertMatch(
+                 {{_, {_, _, <<"NOT_FOUND - no queue '",
+                               ReplyTo:(byte_size(ReplyTo))/binary,
+                               "' in vhost '/'">>}}, _},
+                 Reason)
+    end,
+
+    %% Clean up.
+    #'queue.delete_ok'{} = amqp_channel:call(RequesterCh,
+                                             #'queue.delete'{queue = RequestQueue}),
+    ok = rabbit_ct_client_helpers:close_channel(RequesterCh).
 
 wait_for_queue_declared(Queue, Node, Config) ->
     eventually(