Testing Legacy Code - Safe Refactoring

This talk shows how to make legacy PHP code testable and refactor it while preserving existing behavior. It covers unit testing, mocking, and ways to handle hard-coded dependencies and other difficult code patterns.

Syllabus

Intro
What is legacy code?
What is refactoring?
What is unit testing?
Why would I unit test?
A solution
A better solution
PHPUnit - installation
Anatomy of a unit test
Running the tests
Mocking - Caution!
Mockery - Installation
Mockery - Usage
A method that echoes
A static method call
Testing: hard-coded dependencies
Refactoring hard-coded dependencies
A hard-coded dependency
Refactoring Redirections
Refactoring Exiting
Refactoring: Updating a file
Fake filesystem
Testing: Spaghetti Code
Private methods
Time for a recap...