Categories


Archives


Recent Posts


Categories


CMocka: Unit Testing C Code

astorm

Frustrated by Magento? Then you’ll love Commerce Bug, the must have debugging extension for anyone using Magento. Whether you’re just starting out or you’re a seasoned pro, Commerce Bug will save you and your team hours everyday. Grab a copy and start working with Magento instead of against it.

No Frills Magento Layout is the only Magento front end book you'll ever need. Get your copy today!

Coming at C from a “test legacy code first” point of view is tricky. All those neat test framework features for testing code not written under test (i.e. mocks, etc.) rely on a language’s dynamic nature for implementation details.

You don’t get that easily in C, so it was a pleasure to be introduced to the cmocka framework. In addition to being a fully featured unit test framework (pass/fail tests, fixtures, etc.), cmocka allows you to “mock” specific C functions in a particular test suite using the linker’s --wrap option.

I use the term mock loosely here. The system itself is better described as a monkey patching system (replace one function definition with another), but as userland C lacks the concept of an “object with methods attached”, monkey patching serves the same purpose as mock objects in other languages.

Copyright © Alan Storm 1975 – 2017 All Rights Reserved

Originally Posted: 22nd November 2017