diff --git a/infra/lib/infra/testing.rb b/infra/lib/infra/testing.rb
index ee777838..81785e52 100644
--- a/infra/lib/infra/testing.rb
+++ b/infra/lib/infra/testing.rb
@@ -58,6 +58,13 @@ def assert_changes(actuals, expected)
         expects = expected.map(&:data)
         assert_equal(expects, actuals.map(&:data))
       end
+
+      def assert_nothing_published_within
+        before = event_store.read.to_a
+        yield
+        after = event_store.read.to_a
+        assert_equal before, after
+      end
     end
   end