http://www.everydayunittesting.com/online-courses/clean-code/refactoring-for-testability

Adding tests to legacy code is hard, and many times requires risky changes to the underlying code. How can we make un-testable code testable and do it safely? In this highly-interactive squeeze course we’ll do just that.

In this squeeze-course we’ll cover the following topics:

• Code smells and code anti-patterns
• What is refactoring
• Seams
• Refactoring patterns for a cleaner, testable code.
• Benefits and risks in different scenarios.
• Live refactor a legacy code and prove it’s testable.

Code examples are in C#, Java or JavaScript.