Code quality

The quality of your project is of course going to be important to users of your product or service.

A project is however expected to start as a baby and have its problems at first, and nobody will expect that it is perfect to start with. Over time, you improve and you iterate on design and code. You add tests, you run more tools and you build automated systems to do it for you.

There is no point in putting in all that energy and try to make everything perfect from day one.

As the project grows older, it is expected to mature and to evolve into a solid code base, but as Open Source is forever, there is no fixed timeline for this. You get to spend as much time on this as you see fit. You might just not become super popular and conquer the world properly until the code quality is decent.

How do you achieve good code quality?

There is no magic silver bullet for this, nor is it really an Open Source problem. It is an old software engineering challenge and my steps to accomplish this are:

1. consistent code style (verified by tools)

2. human code reviews before merge

3. tests, tests, tests.

4. CI system that run all tests before merge

5. fuzzing and continuous tests of merged code

6. be responsive on bug reports, add new tests with bugfixes

7. be responsive and friction-less when accepting bugfixes

8. run a bug bounty

9. release often

10. keep at it

Code coverage

In some circles, measuring and achieving some specific code coverage level is considered important and I will not disparage that. I think it is awesome if you manage to write your code and test cases so that you get great code coverage. It will not mean terribly much and you can still have many bugs even so, since code coverage cannot measure code path combinations.

In my projects, the code complexity and the portability and conditional sections of the code etc have always made it extremely hard to generate and measure code coverage to any meaningful level, so I have rarely done so. I believe we have still managed to produce fairly good code just based on the basic principle outlined above.