CodeIgniter test coverage

I like to use libraries; they move the business logic outside of the CodeIgniter MVC framework, where they and their associated test suites can be made independent. Since libraries can be reused in many CodeIgniter projects this maintains their portability, yet it’s simple to integrate them into the whole application test suite, where they can be run from the browser using a custom controller.

Unfortunately, testing anything other than libraries and models is difficult because there’s no way to access the another important type of object: controllers. CodeIgniter positively encourages using controllers to implement business logic, consequently not being able to test them is a serious anomaly.

Integrating a front-end testing framework, such as Selenium, might be the solution, but does that properly test the controller code? I don’t think it does; the target there is the presentation tier at the browser.

The lack of good code coverage bothers me a lot, but I continue to struggle on with CodeIgniter because I’ve found other PHP frameworks to be just as lacking. Is this a general problem with frameworks? I’m tempted to try Ruby on Rails next to find out.