Using GitHub Copilot to Uncover Documentation Bugs: A Case Study

Documentation is crucial, yet it often fails to convey essential information due to the 'curse of knowledge.' Experienced developers write with implicit context, which can alienate new users. This leads to 'silent drift,' where documentation becomes outdated or unclear without any loud failures to signal the issues. Drasi recognized this problem and sought a solution using GitHub Copilot to identify documentation bugs effectively.

The solution involved building a setup with GitHub Actions, Dev Containers, Playwright, and the GitHub Copilot CLI. Inside the Dev Container, the Copilot CLI is invoked with a specialized system prompt using the prompt mode (-p). This configuration allows the agent to execute terminal commands, write files, and run browser scripts, mimicking a human developer's actions. By employing a synthetic user approach, the team could automate the testing of tutorials and documentation, ensuring they are user-friendly and accurate.

In production, this method provides a powerful way to maintain documentation quality. However, be aware that as of late 2025, GitHub updated its Dev Container infrastructure, which requires a minimum Docker version. This change could impact your setup if you're not on the latest version. Overall, using GitHub Copilot in this manner can significantly reduce the burden of manual testing and improve the reliability of your documentation.