From 9479c2e9cce154b70ff6ba0cad16bae32446ac3f Mon Sep 17 00:00:00 2001
From: Philip Kuryloski <kuryloskip@vmware.com>
Date: Thu, 2 Jul 2020 11:33:17 +0200
Subject: [PATCH] Add ?awaitMatch macro

awaitMatch(Guard, Expr, Timeout) reevaluates Expr until it matches
Guard up to Timeout milliseconds from now. It returns the matched
value, in the event said value is useful later in a test.

Additionally simplify an instance of ?assertEqual(true, ... to ?assert(
---
 .../include/rabbit_assert.hrl                 | 21 +++++++++++++++++++
 .../src/rabbit_ct_proper_helpers.erl          |  3 +--
 2 files changed, 22 insertions(+), 2 deletions(-)
 create mode 100644 deps/rabbitmq_ct_helpers/include/rabbit_assert.hrl

diff --git a/deps/rabbitmq_ct_helpers/include/rabbit_assert.hrl b/deps/rabbitmq_ct_helpers/include/rabbit_assert.hrl
new file mode 100644
index 0000000000..a8213e9977
--- /dev/null
+++ b/deps/rabbitmq_ct_helpers/include/rabbit_assert.hrl
@@ -0,0 +1,21 @@
+-define(awaitMatch(Guard, Expr, Timeout),
+        begin
+            ((fun Filter(Horizon) ->
+                      R = Expr,
+                      case (R) of
+                          Guard -> R;
+                          __V -> case erlang:system_time(millisecond) of
+                                     Now when Now < Horizon ->
+                                         timer:sleep(min(50, Horizon - Now)),
+                                         Filter(Horizon);
+                                     _ ->
+                                         erlang:error({awaitMatch,
+                                                       [{module, ?MODULE},
+                                                        {line, ?LINE},
+                                                        {expression, (??Expr)},
+                                                        {pattern, (??Guard)},
+                                                        {value, __V}]})
+                                 end
+                      end
+              end)(erlang:system_time(millisecond) + Timeout))
+        end).
diff --git a/deps/rabbitmq_ct_helpers/src/rabbit_ct_proper_helpers.erl b/deps/rabbitmq_ct_helpers/src/rabbit_ct_proper_helpers.erl
index 581af69f2c..91cfae67e3 100644
--- a/deps/rabbitmq_ct_helpers/src/rabbit_ct_proper_helpers.erl
+++ b/deps/rabbitmq_ct_helpers/src/rabbit_ct_proper_helpers.erl
@@ -20,8 +20,7 @@
 -export([run_proper/3]).
 
 run_proper(Fun, Args, NumTests) ->
-    ?assertEqual(
-       true,
+    ?assert(
        proper:counterexample(erlang:apply(Fun, Args),
 			     [{numtests, NumTests},
 			      {on_output, fun(".", _) -> ok; % don't print the '.'s on new lines