GitHub Actions

GitHub Actions is an important part of building production-ready single-spa systems. This lesson explains what github actions means, how it works, and how to apply it with practical examples you can reuse.

GitHub Actions Overview

At its core, github actions is about doing one thing well inside your single-spa project. Once you understand the pattern, you can apply it consistently across features and teams.

Good github actions pays off across the whole codebase: fewer surprises, easier testing, and smoother onboarding. The snippet below is a solid starting point.

import { registerApplication, start } from 'single-spa';

registerApplication({
  name: '@org/app',
  app: () => System.import('@org/app'),
  activeWhen: ['/app'],
});

start();

single-spa orchestrates multiple framework apps on one page through a root config.

GitHub Actions Example

registerApplication({
  name: '@org/app',
  app: () => System.import('@org/app'),
  activeWhen: ['/app'],
});
start();

Start from a minimal GitHub Actions example and grow it only as needed.
Keep configuration explicit so GitHub Actions behaves the same in every environment.
Name things clearly so teammates understand your GitHub Actions at a glance.
Add tests around GitHub Actions early to lock in expected behaviour.

Single-SPA Cheatsheet

Core single-spa APIs related to github actions.

API	Example	Purpose
registerApplication	`registerApplication({ name, app, activeWhen })`	Register a micro frontend
activeWhen	`activeWhen: ['/checkout']`	Route ownership
start	`start()`	Begin routing
bootstrap	`export async function bootstrap()`	One-time setup
mount	`export async function mount(props)`	Render the app
unmount	`export async function unmount(props)`	Clean up the app
import map	`systemjs-importmap`	Locate app bundles

How GitHub Actions Works in Single-SPA

GitHub Actions is part of how single-spa lets multiple applications — even in different frameworks — coexist on one page. A root config registers each app and controls when it is active.

single-spa orchestrates multiple framework apps on one page through a root config.

A root config registers apps and calls start().
Each app exports bootstrap, mount, and unmount lifecycles.
activeWhen decides which routes each app owns.
Import maps resolve each app's bundle at runtime.

Practical Guidance for GitHub Actions

For reliable micro frontends, github actions should isolate failures and keep shared state minimal. Let each team own its app end to end while agreeing on a few shared contracts.

Concern	Recommendation
Isolation	One app's crash should not break others
Shared state	Prefer shared utility modules over globals
Routing	Keep activeWhen rules explicit and non-overlapping
Deployment	Release via import-map updates per app

Common Mistakes

Copying github actions snippets without understanding what each line does.
Skipping error handling and edge cases when wiring up github actions.
Leaving github actions untested, so regressions slip into production.
Over-engineering github actions before you actually need the extra flexibility.

Key Takeaways

GitHub Actions is a core part of working effectively with single-spa.
Start small and keep github actions focused on a single responsibility.
Apply consistent patterns so github actions scales across your project.
Test and document github actions to keep it maintainable over time.

Pro Tip

Bookmark this github actions pattern and reuse it. Consistency across your single-spa codebase is worth more than clever one-off solutions.