Static site generators like Jekyll or Hugo are awesome to quickly publish a website online. Thanks to GitHub and Netlify, you can leverage powerful collaboration tools and free hosting to have a website up and running quickly. You’ll be able to deploy and update your website in minutes without worrying about hosting. This is super powerful.

One thing I’ve not seen a lot for static websites which is present in traditional software is tests: software you write to prove or make sure that your code does what you expect it to do. Sure, static websites have way less code than libraries or backends, but still: you can quickly have tens of posts and hundreds of lines of YAML in data files. It makes sense to write quick tests to ensure things like required keys are present for posts or foreign key consistency in data files. Tests ensure you have a high quality content on your website and can avoid broken layout which you would detect after browsing your static website.

Writing tests for Jekyll

How would you write tests for a Jekyll website? At the end of the day, static websites are composed of data files (usually in YAML) and content files in Markdown. Standard programming languages (Python, Ruby, PHP) can easily parse these files and you can write assertions about the content of them. These tests should be executed after every git push to perform continuous integration. You can use a platform like CircleCI or GitHub Actions to do this.

Jekyll tests code sample

Here is a sample code to run tests on CircleCI for Markdown posts: making sure required keys are there, tags are present and come from a predefined list, images and Twitter usernames have an expected format. These tests are written using Python 3.6 but you can use whatever programming language you like. You can also write tests for data files in YAML. It gets powerful when you write tests combining data files and content files in Markdown.

These tests run in less than 10 seconds on CircleCI after pushing your code and can quickly catch small mistakes. This is a straightforward way to improve the quality of your static website.