Preface¶

Estimated time to read: 1 minute

Software development was never easier than it is today. With a couple of lines of Python you can perform complex operations, and making changes to your code base is usually just a matter of a few key strokes. However, the sheer number of possibilities has also grown the complexity of the software we create. In only a moderately large application it's almost impossible to verify all the combinations the code can be run with.

When your software has no tests that you can run upon each change you're unable to tell whether existing functionality is unaffected. And soon, your software starts feeling like a vintage car: When you fix the front light the rear bumper falls off. You lose control.

That's why we need tests. With great power comes great responsibility. There is no stable software without tests.