Describe the bug

shadcn add mutates unrelated string literals during install when the target project's components.json has:

"tailwind": {
  "cssVariables": false
}

In my case, this valid code:

const value = parts.join(" ");

was written to disk as:

const value = parts.join("");

I reduced this to a minimal repro in a plain Vite React TypeScript app.

The likely root cause is transformCssVars: it appears to walk all StringLiteral nodes and apply trimming/mapping logic, which incorrectly affects non-class strings like " ".

I believe the fix is to scope that transform to actual class strings (className, cn(...), clsx(...), cva(...), etc.) instead of all string literals. Happy to send a PR if that approach makes sense.

Affected component/components

Not specific to one component. This appears to affect any registry component installed via shadcn add when: tailwind.cssVariables is false, and the source contains a meaningful non-class string literal

How to reproduce

1. Create a plain Vite React TypeScript app:

cd /tmp
pnpm dlx create-vite@latest shadcn-vite-mini-repro --template react-ts
cd /tmp/shadcn-vite-mini-repro

2. Add this components.json:

{
  "$schema": "https://ui.shadcn.com/schema.json",
  "style": "default",
  "rsc": false,
  "tsx": true,
  "tailwind": {
    "config": "",
    "css": "",
    "baseColor": "neutral",
    "cssVariables": false,
    "prefix": ""
  },
  "aliases": {
    "components": "@/components",
    "utils": "@/lib/utils",
    "ui": "@/components/ui",
    "lib": "@/lib",
    "hooks": "@/hooks"
  }
}

3. Create /tmp/space-bug.json:

{
  "name": "space-bug",
  "type": "registry:component",
  "title": "Space Bug",
  "description": "Minimal repro for string literal trimming",
  "files": [
    {
      "path": "registry/test/components/space-bug.tsx",
      "type": "registry:component",
      "content": "export default function SpaceBug() {\n  const parts = [\"a\", \"b\"];\n  const value = parts.join(\" \");\n  return <div>{value}</div>;\n}\n"
    }
  ]
}

4. Install it:

pnpm dlx shadcn@latest add /tmp/space-bug.json --yes --overwrite

5. Inspect the written file.

Expected:

const value = parts.join(" ");

Actual:

const value = parts.join("");

Note: If components.json is changed to "cssVariables": true, the bug no longer reproduces.

Codesandbox/StackBlitz link

I don't have a hosted reproduction, but the local repro above is minimal and verified.

Logs

System Info

- `shadcn`: `4.0.5`
- Node.js: `22.22.0`
- Package manager: `pnpm`
- Project type: plain Vite React TypeScript app
- OS: macOS

Before submitting

• I've made research efforts and searched the documentation
• I've searched for existing issues