Transform function can change response for downstream links

[bentburton]

I am trying to include the result that the backend is sending with the include fetch results flag. If I modify the breadcrumb information It modifies it for the code calling the request instead of only modifying what is sent to sentry.

Here is an example:

[bentburton]

When doing this the code calling the login mutation is getting the token back as REDACTED. The act of filtering the breadcrumb is affecting the actual response

[spawnia]

Indeed, JavaScript objects are mutable. The object spread you are doing with const filteredBreadcrumb = { ...breadcrumb }; is only doing a shallow copy.

I recognize this is a potential footgun, so I am updating the docs to warn about it.