Craftsperson's Guide to GitHub Actions

Learn to build production-ready GitHub Actions with clean architecture, comprehensive testing strategies, and reliable release pipelines, transforming fragile automation scripts into maintainable software.


Have you ever rushed to push a GitHub Action, only to watch it fail in the pipeline? Or inherited an action so tightly coupled to infrastructure that testing it locally felt impossible? You're not alone.

GitHub Actions have become the backbone of modern CI/CD workflows; yet, we often treat them as throwaway scripts rather than production-grade software. What you usually get is: brittle automation, slow feedback loops, and extensive trial and error in your pipelines.

This year at Polar Squad, I've spent considerable time assisting a platform engineering team in building reusable GitHub Actions used daily by hundreds of developers.

Here's what I learned: the difference between fragile scripts and reliable automation lies in applying the same modern software engineering principles you'd use for any critical production system.

What You'll Learn

This series demonstrates how to build GitHub Actions that are:

  • Testable: Run comprehensive tests locally in seconds, not minutes.

  • Maintainable: Separate business logic from infrastructure concerns using clean architecture.

  • Reliable: Achieve confidence through unit tests, property-based tests, and mutation testing.

  • Production-ready: Build, release, and verify your actions with automated pipelines.

The techniques I share aren't specific to GitHub Actions. They're fundamental software engineering practices applied to CI/CD. Clean architecture ensures your code is easy to understand and cheap to change. Fast-running tests provide immediate feedback on changes. The ability to refactor safely means you can adapt to evolving requirements without fear.

Who This Guide Is For

If you're a software engineer building JavaScript or TypeScript-based GitHub Actions and want to move beyond the "push and pray" development, this guide is for you. Whether you're creating actions for your team or publishing them publicly, these practices will save you time and headaches.

I've prepared an example repository with a fully functional GitHub Action that demonstrates every principle discussed in this series. Clone it, experiment with it, and use it as a foundation for your own actions.

Series Chapters

I have divided the series into three focused chapters, each building on the previous one:

Follow along over the next few weeks as we explore how to build automation that’s testable, maintainable and actually enjoyable to work with.

Niko Heikkilä