Nothing crazy required public EmployeeController(EmployeeMapper mapper){} public Employee create() { ... mapper.save(employee); return employee; } Done. All

Nothing crazy required public EmployeeController(EmployeeMapper mapper){} public Employee create() { ... mapper.save(employee); return employee; } Done. All you do now is create a mock employee mapper in your tests, and you can verify just what you want in the Controller instead of anything else You've got * Single responsibility classes (Controller manages employee creation business logic; Mapper is a dumb database wrapper; If you want to go even further, use a Repository instead of a Mapper to introduce one more layer of abstraction between the data model, that way you can slide in caching or in-memory replacements, or what have you at will) * Clean dependencies. There's nothing hidden about what this class needs to get it's work done