In T274545, we accidentally merged a change that probably changed the order of parameter serialization. It was reverted before hitting any production servers. But this was a warning to us, that we have to make sure our sidebar work doesn't result in reordered serialization. This would create "dirty diffs" when using Visual Editor, historically a very sore topic.
- Write tests that cover current serialization order.
- When paramOrder given.
- When paramOrder not given.
- When parameters are unspecified.
- Update TemplateData help to clarify the effect of paramOrder on serialization.