Tests Needed #13
Description
Although I have some end to end tests which I run in SHEETS after making changes, they are limited and don't check things which might be going wrong - but the end result is still correct (I.e. is the short cache working, is the long cache working, are the cache values being expired correctly - hard to tell).
Making any change leaves me not confident that something else is not being broken at the same time. Also the current method of testing is not instant and is time consuming to check.
Much of this custom function is dependent on calling Google sheets API functions - so a valid test environment needs to simulate those calls correctly.