improve comment

test/test_helper.rb

@@ -144,11 +144,11 @@ def assert_event(tag, expected_additional, actual)
     assert_equal actual.additional_type.new(user_agent_info:, **expected_additional), actual.additional
   end
 
-  # Asserts that both are the same nested hash, using equality checks unless
-  # the value is a hash, in which case it will recursively check the nested hash
-  # The purpose of this assertion is mostly to provide a more useful error when
-  # a nested hash contains different elements instead of overwhelming the user
-  # with a giant nested hash diff that is mostly sorting problems.
+  # Hashes with different orders will still be equal according to assert_equal,
+  # but when they are not equal, the output diff will print them in their
+  # original order, which makes it hard to see what is actually different.
+  # Sort the hashes and any nested hashes (leaving array order untouched) before
+  # comparing them to make the diff output more useful.
   def assert_equal_hash(expected, actual, context = "expected")
     assert_equal deep_sort_hashes(expected), deep_sort_hashes(actual), "Expected equal elements in #{context}"
   end