Writing code that can be tested is not an art form. It takes thought and consideration to keep our code in the best possible shape.

Let's take a look at the warning signs with code examples that can make our code harder to test.

* Does your constructor do too much work?
* Are you using collaborator objects?
* Do you have global state or singletons?
* Do your classes do too much?

Come and see what can be done to improve upon or fix these issues.