For months (even years) I wanted to compile a list of advice I have on code reviewing. Initially, for myself but recently I thought it’d be a good idea for a blog post. Some of the advice is generic and some is quite opinionated.
Tests can be very useful. They provide some guarantees that something works as expected; they can prevent you from introducing breaking changes; and they can act as documentation. It makes a lot of sense to put an emphasis on testing. Especially, as a reviewer, because your job is to make sure that proposed changes match the product requirements
I truly believe that written intention/purpose of tests is more important that the tests (assertions) themselves. And that’s what specs are in the nutshell: they describe the purpose behind some function/module/feature/etc. If there’s no purpose, why are you even building it?
Well-written specs also help you write better tests because it becomes clearer what exactly needs to be tested. They also help the reviewers to come to an informed conclusion whether a test is good or not.