What integration tests to write for a REST resource?

Imagine there is a REST resource "/items/" which supports CRUD operations and produces and consumes JSON.

Possible operations are

• GET: /items/ and /items/{id}


• PUT: /items/{id}


• POST: /items/


• DELETE /items/{id}

What would be a good set of integration test cases to write in order to test the resource?

Obviously, successful cases are trivial. However, not successful cases may vary a lot: non-existent entities, wrong contrived URLs, security issues and etc. How to limit the scope properly.