viewcomponent-coder

ViewComponent is a framework for creating encapsulated, testable UI components in Rails. It replaces partials with component classes, enabling slots for flexible content injection, style variants for multiple appearances, and isolated testing. This approach keeps components modular and prevents tight coupling to view logic.

Slots are named content areas within a ViewComponent that accept flexible content from parent templates. Instead of passing data through partials, slots let you define what content goes where—headers, bodies, footers—making components reusable across different layouts without parameter explosion.

Lookbook generates interactive preview pages for your ViewComponents, letting you showcase variants, slots, and edge cases without running the full Rails app. It integrates directly with ViewComponent to auto-document component behavior and helps validate design consistency across your UI library.

Yes, ViewComponent supports isolated unit testing through RSpec or Minitest. You test component rendering, slot behavior, and variant logic independently without loading entire Rails views, making tests faster and more focused on component behavior.

Refactoring partials to ViewComponents works best for reusable, stateful UI patterns—buttons, cards, modals, form fields. Simple one-off template snippets don't need the overhead. Prioritize partials that are used multiple times or need variant logic, style customization, or isolated testing.

ViewComponent integrates with Turbo and Hotwire for dynamic updates. Components render predictably on server and integrate with Turbo Streams for partial page replacement, making them suitable for real-time UI patterns without JavaScript framework lock-in.