Files
cal-diy-oidc/.cursor/skills/vercel-react-best-practices/rules/bundle-preload.md
T
Udit Takkar 7a9fdd5a0c feat: add react best practises and web design skills (#26918)
## What does this PR do?

This PR adds https://vercel.com/blog/introducing-react-best-practices for your coding agent using `npx add-skill vercel-labs/agent-skills` command

The skills are added to `.claude/`, `.cursor/`, and `.opencode/` directories to provide React and Next.js performance optimization guidance for AI-assisted workflows.

## Updates since last revision

Addressed Cubic AI review feedback for issues with confidence >= 9/10:

- **rerender-dependencies.md** - Replaced `console.log(user.id)` with `fetchUserDetails(user.id)` to avoid logging sensitive information
- **server-after-nonblocking.md** - Removed `sessionCookie` from `logUserAction` call to avoid logging sensitive authentication data, added `await` to async call
- **bundle-conditional.md** - Added `loadError` state and `setLoadError` setter to fix undefined `setEnabled` reference
- **advanced-event-handler-refs.md** - Updated `useWindowEvent` handler signature to accept `Event` parameter and forward it to the stored handler
- **rerender-derived-state.md** - Closed `<nav>` elements in both examples for valid JSX

Fixes applied to both `.claude` and `.cursor` skill directories for consistency.

## Mandatory Tasks (DO NOT REMOVE)

- [x] I have self-reviewed the code (A decent size PR without self-review might be rejected).
- [x] N/A I have updated the developer docs in /docs if this PR makes changes that would require a [documentation change](https://cal.com/docs). If N/A, write N/A here and check the checkbox.
- [x] N/A, I confirm automated tests are in place that prove my fix is effective or that my feature works.

## How should this be tested?

These are documentation files for AI coding agents. No runtime testing required - review the markdown files to verify the example code snippets are correct.

## Checklist for human review

- [ ] Verify example code snippets in the skill files are syntactically correct
- [ ] Confirm the fixes don't introduce new issues in the documentation examples
- [ ] Check that `.claude` and `.cursor` directories have consistent content

---

Link to Devin run: https://app.devin.ai/sessions/f7f7e67fdeea4b22a4817d63ed9e1759
Requested by: unknown ()
2026-01-16 17:19:34 +05:30

1.1 KiB

title, impact, impactDescription, tags
title impact impactDescription tags
Preload Based on User Intent MEDIUM reduces perceived latency bundle, preload, user-intent, hover

Preload Based on User Intent

Preload heavy bundles before they're needed to reduce perceived latency.

Example (preload on hover/focus):

function EditorButton({ onClick }: { onClick: () => void }) {
  const preload = () => {
    if (typeof window !== 'undefined') {
      void import('./monaco-editor')
    }
  }

  return (
    <button
      onMouseEnter={preload}
      onFocus={preload}
      onClick={onClick}
    >
      Open Editor
    </button>
  )
}

Example (preload when feature flag is enabled):

function FlagsProvider({ children, flags }: Props) {
  useEffect(() => {
    if (flags.editorEnabled && typeof window !== 'undefined') {
      void import('./monaco-editor').then(mod => mod.init())
    }
  }, [flags.editorEnabled])

  return <FlagsContext.Provider value={flags}>
    {children}
  </FlagsContext.Provider>
}

The typeof window !== 'undefined' check prevents bundling preloaded modules for SSR, optimizing server bundle size and build speed.