If an exception breaks business logic, then you can test the code by testing business logic. How do null pointer exceptions arise? Inconsistent data: you have

If an exception breaks business logic, then you can test the code by testing business logic. How do null pointer exceptions arise? Inconsistent data: you have code paths that implicitly assume invariants. Trivial cases like “this field is not provided” and more complex ones like “these fields have a specific relationship”. You can often move those assumptions into the data structure in any language. Then your tests become a matter of generating and transforming data from a holistic perspective instead of micromanaging individual code paths.