##How To Build a Component Library That Your Coworkers Will Love You For
So you've been tasked with creating a component for your design system.
Why a Design System Matters
A design system ensures consistency. Users see the same patterns again and again.
It reduces confusion. It also increases productivity for developers and designers.
Gather Requirements
Ask if the component is essential. (YAGNI - You Ain't Gonna Need It). Resist creating a component nobody will use.
Decide what the API should look like. Keep it small. Ensure it’s flexible enough for future use.
Check if you need one component or a composition of many smaller components. A single component can be quick to build. Multiple smaller components can be more reusable.
Steal from the Great
Look at the source code in Shadcn and Material UI.
See how they structure components. Notice how they use design tokens and accessibility.
Learn from them. Adapt their patterns to your use case.
Accessibility
Many regions require compliance with standards like WCAG 2.1. Laws like the European Accessibility Act or similar acts in the United States and Canada can lead to legal trouble if you fail to comply.
Use semantic HTML. This ensures screen readers can parse your interface.
Build on native elements first. They already include validation, accessibility hooks, and more. If you need special components, try Radix UI primitives.
Monorepo
Put each component in its own package. If you update a dependency for one component, you avoid accidentally updating all others.
You manage versioning more clearly. It also makes it easier to release updates for a single component.
Trend of Copying Components Instead of Installing Them
Shadcn helped popularize copying source code directly. You have total control of the code. You can adjust styles and behavior without waiting for a library update.
The tradeoff? You must maintain it yourself. If the original library updates, you might miss out. But you gain complete ownership.
Private NPM Registry
You might store your packages on a private registry. This helps you control releases and limit access.
It also ensures your internal tools remain internal.
Tests
Write tests for every component with Vitest and React Testing Library. Test all props and behaviors.
Consider using visual regression tests with Percy. It detects style regressions.
Playground
Use a playground for your components. Storybook is the most popular option.
A playground helps you test props, styles, and states. It allows designers and developers to collaborate.
Documentation
Consider starting with RDD (Readme-Driven Development).
Then build the component to match the docs. This keeps your API consistent with your documentation.
Whew you use a monorepo where every component is its own package, you give each component its own README.
Versioning
Keep a clear versioning strategy. Use semantic versioning if possible.
Use tools like commitlint with conventional commits to auto generate changelog entries.
Performance
Watch for bundle size. Use tree-shaking.
Theming
Use tokens for color, typography, and spacing. This makes theming easier. Pick your tokens wisely. (In my opinion, Shadcn kinda nailed it.)
Conclusion
Build great components. Keep them simple. Ensure they serve a real purpose.