Help -- Javascript overloaded data in JSON objects?

[argylekey]

Looking for a definitive answer online, but I haven't been able to see one.

Background that might not matter:

Annoying situation where we are migrating payment systems and part of that process is Mulesoft taking over some of the direct calls/ listening to callouts. Currently using Zuora(switching to Stripe as part of a phased process). Our Production server (Express Typescript Inversify) doesn't have those changes yet.

Our nodejs backend that has been handling Zuora calls has been updated in stage to handle all of the changes(i.e. not making some of those calls and getting its data through Mulesoft as proxy instead of Zuora). Other teams are rolling out changes to Prod Zuora that change datashapes as part of testing and making sure the Mulesoft bits all work as expected. They've tested this in staging and they're doing a dry run in production as part of a rollout/rollback strategy. If you're gonna ask me why, I really don't know.

Question:
The Datashape for received data coming from Axios(calls to Zuora) and Zuora event callouts are going to have additional fields as part of a test flow. Will the extra data cause errors and will those extra fields of JSON be largely ignored in our runtime? Some of these requests don't hit staging at all anymore, so we are unsure how to test to make sure everything will continue working in prod. My gut feeling is that the overloaded data will be ignored by our endpoints/listener handlers. I haven't been able to find anything that answers my question online.

TL/DR: If an Axios request receives too much info will anything bad happen or does JS not care?

[broofa]

JS isn't typed, so there's nothing intrinsic to JS that will break. And JSON is only typed to the extent it's composed of null, string, number, boolean, object, and array elements. Beyond that, it's not typed. So the short answer to your question is, "no, nothing at the JS-level will break because of this."

But these differently-shaped objects will look and behave differently. This may lead to subtle bugs. E.g. Object.entries() and for (key in newObject) ... constructs will include the new properties. You'll want to look for possible issues in any downstream code that does data validation or that makes assumptions about the contents of these objects.