dev/core#567 Add test shell

[eileenmcnaughton]

Overview

This adds the test shell for https://lab.civicrm.org/dev/core/-/issues/567 which has previously been blocked on needing a test.

I looked at #22100 and thought to direct to where the test would go & then realised the test would be easy to write. However, I've left is as not actually testing - just providing clues. When I dug into the code that would need changing I realised I wasn't comfortable making the proposed change without some cleanup prior to making the change. I will separately put up a PR to un-share the processFormContribution function as the shared nature of that function is a major contributor to the problems with it.

Before

Hard for people to know where to add tests

After

Shell test exists - will add to the issue

Technical Details

Comments

[civibot]

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