Track requeue history

as described in rabbitmq/rabbitmq-website#2095

This commit adds a test case and fixes a bug in the broker to allow
using `array` type in the value of the modified annotations.

deps/amqp10_client/src/amqp10_client_session.erl

@@ -1178,14 +1178,16 @@ wrap_map_value(true) ->
     {boolean, true};
 wrap_map_value(false) ->
     {boolean, false};
-wrap_map_value(V) when is_integer(V) ->
-    {uint, V};
+wrap_map_value(V) when is_integer(V) andalso V >= 0 ->
+    uint(V);
 wrap_map_value(V) when is_binary(V) ->
     utf8(V);
 wrap_map_value(V) when is_list(V) ->
     utf8(list_to_binary(V));
 wrap_map_value(V) when is_atom(V) ->
-    utf8(atom_to_list(V)).
+    utf8(atom_to_list(V));
+wrap_map_value(TaggedValue) when is_atom(element(1, TaggedValue)) ->
+    TaggedValue.
 
 utf8(V) -> amqp10_client_types:utf8(V).
 

deps/rabbit/src/mc_util.erl

@@ -52,9 +52,8 @@ infer_type(V) when is_integer(V) ->
     {long, V};
 infer_type(V) when is_boolean(V) ->
     {boolean, V};
-infer_type({T, _} = V) when is_atom(T) ->
-    %% looks like a pre-tagged type
-    V.
+infer_type(TaggedValue) when is_atom(element(1, TaggedValue)) ->
+    TaggedValue.
 
 utf8_string_is_ascii(UTF8String) ->
     utf8_scan(UTF8String, fun(Char) -> Char >= 0 andalso Char < 128 end).

deps/rabbit/test/amqp_client_SUITE.erl

@@ -501,59 +501,67 @@ modified_quorum_queue(Config) ->
     ok = amqp10_client:send_msg(Sender, Msg2),
     ok = amqp10_client:detach_link(Sender),
 
-    {ok, Receiver} = amqp10_client:attach_receiver_link(Session, <<"receiver">>, Address, unsettled),
+    Receiver1Name = <<"receiver 1">>,
+    Receiver2Name = <<"receiver 2">>,
+    {ok, Receiver1} = amqp10_client:attach_receiver_link(Session, Receiver1Name, Address, unsettled),
+    {ok, Receiver2} = amqp10_client:attach_receiver_link(Session, Receiver2Name, Address, unsettled),
 
-    {ok, M1} = amqp10_client:get_msg(Receiver),
+    {ok, M1} = amqp10_client:get_msg(Receiver1),
     ?assertEqual([<<"m1">>], amqp10_msg:body(M1)),
     ?assertMatch(#{delivery_count := 0,
                    first_acquirer := true},
                  amqp10_msg:headers(M1)),
-    ok = amqp10_client:settle_msg(Receiver, M1, {modified, false, true, #{}}),
+    ok = amqp10_client:settle_msg(Receiver1, M1, {modified, false, true, #{}}),
 
-    {ok, M2a} = amqp10_client:get_msg(Receiver),
+    {ok, M2a} = amqp10_client:get_msg(Receiver1),
     ?assertEqual([<<"m2">>], amqp10_msg:body(M2a)),
     ?assertMatch(#{delivery_count := 0,
                    first_acquirer := true},
                  amqp10_msg:headers(M2a)),
-    ok = amqp10_client:settle_msg(Receiver, M2a, {modified, false, false, #{}}),
+    ok = amqp10_client:settle_msg(Receiver1, M2a, {modified, false, false, #{}}),
 
-    {ok, M2b} = amqp10_client:get_msg(Receiver),
+    {ok, M2b} = amqp10_client:get_msg(Receiver1),
     ?assertEqual([<<"m2">>], amqp10_msg:body(M2b)),
     ?assertMatch(#{delivery_count := 0,
                    first_acquirer := false},
                  amqp10_msg:headers(M2b)),
-    ok = amqp10_client:settle_msg(Receiver, M2b, {modified, true, false, #{}}),
+    ok = amqp10_client:settle_msg(Receiver1, M2b, {modified, true, false, #{}}),
 
-    {ok, M2c} = amqp10_client:get_msg(Receiver),
+    {ok, M2c} = amqp10_client:get_msg(Receiver1),
     ?assertEqual([<<"m2">>], amqp10_msg:body(M2c)),
     ?assertMatch(#{delivery_count := 1,
                    first_acquirer := false},
                  amqp10_msg:headers(M2c)),
-    ok = amqp10_client:settle_msg(Receiver, M2c,
-                                  {modified, true, false,
-                                   #{<<"x-opt-key">> => <<"val 1">>}}),
-
-    {ok, M2d} = amqp10_client:get_msg(Receiver),
+    ok = amqp10_client:settle_msg(
+           Receiver1, M2c,
+           {modified, true, false,
+            %% Test that a history of requeue events can be tracked as described in
+            %% https://rabbitmq.com/blog/2024/10/11/modified-outcome
+            #{<<"x-opt-requeued-by">> => {array, utf8, [{utf8, Receiver1Name}]}}
+           }),
+
+    {ok, M2d} = amqp10_client:get_msg(Receiver2),
     ?assertEqual([<<"m2">>], amqp10_msg:body(M2d)),
     ?assertMatch(#{delivery_count := 2,
                    first_acquirer := false},
                  amqp10_msg:headers(M2d)),
-    ?assertMatch(#{<<"x-opt-key">> := <<"val 1">>}, amqp10_msg:message_annotations(M2d)),
-    ok = amqp10_client:settle_msg(Receiver, M2d,
-                                  {modified, false, false,
-                                   #{<<"x-opt-key">> => <<"val 2">>,
-                                     <<"x-other">> => 99}}),
-
-    {ok, M2e} = amqp10_client:get_msg(Receiver),
+    #{<<"x-opt-requeued-by">> := {array, utf8, L}} = amqp10_msg:message_annotations(M2d),
+    ok = amqp10_client:settle_msg(
+           Receiver1, M2d,
+           {modified, false, false,
+            #{<<"x-opt-requeued-by">> => {array, utf8, [{utf8, Receiver2Name} | L]},
+              <<"x-other">> => 99}}),
+
+    {ok, M2e} = amqp10_client:get_msg(Receiver1),
     ?assertEqual([<<"m2">>], amqp10_msg:body(M2e)),
     ?assertMatch(#{delivery_count := 2,
                    first_acquirer := false},
                  amqp10_msg:headers(M2e)),
-    ?assertMatch(#{<<"x-opt-key">> := <<"val 2">>,
+    ?assertMatch(#{<<"x-opt-requeued-by">> := {array, utf8, [{utf8, Receiver2Name}, {utf8, Receiver1Name}]},
                    <<"x-other">> := 99}, amqp10_msg:message_annotations(M2e)),
-    ok = amqp10_client:settle_msg(Receiver, M2e, modified),
+    ok = amqp10_client:settle_msg(Receiver1, M2e, modified),
 
-    ok = amqp10_client:detach_link(Receiver),
+    ok = amqp10_client:detach_link(Receiver1),
     ?assertMatch({ok, #{message_count := 1}},
                  rabbitmq_amqp_client:delete_queue(LinkPair, QName)),
     ok = rabbitmq_amqp_client:detach_management_link_pair_sync(LinkPair),