Sameer Nyaupane has posted the latest part in his "PHP Test Driven Development" series of tutorials. In this latest post, part five, he focuses on integration testing, ensuring the components are all working together as they should.

Let’s learn about Integration testing today. Integration testing is a method of testing by passing in the real dependencies and thus testing out the integration between two or more objects.

He updates the examples from his previous post to test the integration between the Math and Calculate classes. He walks you through the changes required to the phpunit.xml configuration and the creation of the initial test classes. He goes through each line of the tests, explaining what it's doing and how mocks are used to help with dependencies.