How To Write Crud User Stories For Validation . Keep it simple but don't be afraid to add more detail is it helps. Ideally, product users should write user stories. How to implement CRUD + form validation in spa project from www.fatalerrors.org In this tutorial, we will learn how to apply validation in the same. The negative test cases are the irregular user flows that are expected: A user story is an informal, general explanation of a software feature written from the perspective of the end user.