ui-react-rules

name	ui-react-rules
description	Project conventions for the packages/ui-react component library — where component source, barrels, and config live, the search-before-adding workflow, Base UI as the primitive library, and where the generic shadcn skill's defaults are overridden. Use whenever adding, searching for, or modifying a UI component in packages/ui-react, or whenever the generic shadcn skill's guidance conflicts with this package's existing source.
metadata	{"type":"reference","author":"lordpluha"}

ui-react rules — @spotify/ui-react

The generic shadcn skill is linked at .claude/skills/shadcn/. This file records the spotify-clone overrides; when guidance conflicts, this file and the existing package source win.

Ownership and config

• Config: packages/ui-react/components.json
• Component source: packages/ui-react/src/components/ui/<kebab-name>/
• Component barrel: packages/ui-react/src/components/ui/index.ts
• Package barrel: packages/ui-react/src/index.ts
• Class helper: cn from packages/ui-react/src/lib/utils.ts
• Primitive library: Base UI (@base-ui-components/react)
• Consumer import: import { Button } from '@spotify/ui-react'

The existing components.json contains legacy Tailwind/shadcn fields. Inspect generated diffs carefully; package source, Tailwind v4 setup, and design-token pipeline are authoritative.

Before creating a component

1. Search existing exports and component folders.
2. Search the shadcn registry through the CLI and read current component docs. MCP is disabled by default in .mcp.json for token budget; use it only if enabled locally.
3. Prefer composition from existing @spotify/ui-react components.
4. Add a new primitive only when no existing component or composition fits.

Run CLI commands from packages/ui-react/:

pnpm dlx shadcn@latest info
pnpm dlx shadcn@latest search @shadcn -q "<need>"
pnpm dlx shadcn@latest docs <component>
pnpm dlx shadcn@latest add <component> --dry-run

Never overwrite an existing component without explicit approval. Use --diff and merge upstream changes while preserving local variants and tests.

Package component shape

components/ui/<name>/
  <name>.tsx
  <name>.stories.tsx
  <name>.unit-spec.tsx
  <name>.int-spec.tsx
  <name>.snapshot-spec.tsx
  <name>.screenshot-spec.tsx
  index.ts

Not every first draft needs every test file, but public primitives should converge on this matrix. Export through the local barrel and components/ui/index.ts.

Project-specific rules

• Component APIs are project-owned. Inspect the installed source before applying generic Base UI or Radix advice. For example, the current Button intentionally exposes asChild through the package's Slot helper.
• Use design tokens generated from packages/tokens/tokens.json.
• Use cn() and CVA for variants.
• Use icons from @/icons or the package's configured icon source before adding another icon library.
• Forms compose the existing package primitives (Form, InputGroup, InputContext, InputWithLabel, etc.) and React Hook Form + Zod.
• Toasts use the existing Sonner export.
• New UI code needs Storybook coverage and tests proportional to behaviour.

Known overrides to the generic skill:

Generic guidance	spotify-clone convention
Base UI triggers always use render	Follow the installed component API; Button currently supports asChild
Button has no loading prop	Existing Button has isLoading; preserve compatibility unless intentionally redesigning it
Generic flat component destination	Use components/ui/<kebab-name>/<name>.tsx plus local and package barrels
Generic icon library assumption	Prefer generated @/icons and existing package icons
Generic form primitives	Reuse the form/input primitives already exported by @spotify/ui-react

After adding or updating a component:

pnpm --filter @spotify/ui-react check-types
pnpm --filter @spotify/ui-react lint
pnpm --filter @spotify/ui-react test:unit
pnpm --filter @spotify/ui-react test:int

Run snapshot/screenshot updates only when the output change is intentional.

Related rules and skills

• shadcn — the generic, project-agnostic shadcn reference this file overrides.
• project-conventions — the cross-cutting rules this file specializes.