# Rolldown minifier drops `while(` keyword — invalid syntax in Safari

**Status:** To be filed
**Workaround applied:** `build: { minify: "esbuild" }` in `vite.config.mts`

## Summary

Rolldown's minifier drops the `while(`/`for(;` keyword when a `while (x in globalThis)` loop is bundled alongside other module-level variable declarations. The resulting output is a syntax error that crashes Safari.

## Target repositories

- https://github.com/rolldown/rolldown/issues
- https://github.com/oxc-project/oxc/issues (underlying minifier)

## Environment

| Package | Version |
|---|---|
| `vite` | 8.0.1 |
| `rolldown` | 1.0.0-rc.10 |
| `@oxc-project/types` | 0.120.0 |
| Triggered by | `@ark/schema` 0.56.0 / `arktype` 2.1.29 |

## Source

File: `node_modules/@ark/schema/out/shared/registry.js`

```js
let _registryName = "$ark";
let suffix = 2;
while (_registryName in globalThis)
    _registryName = `$ark${suffix++}`;
export const registryName = _registryName;
```

## Actual minified output

```js
un=Pe(`implementedTraits`),dn=`$ark`,fn=2;dn in globalThis;)dn=`$ark${fn++}`;var pn=dn;
```

The `while(` keyword is missing. The orphaned `)` is a syntax error.

## Expected output

```js
var dn=`$ark`,fn=2;for(;dn in globalThis;)dn=`$ark${fn++}`;var pn=dn;
```

## Impact

Safari throws: `SyntaxError: Unexpected keyword 'in'. Expected a ';' following a return statement.`
Chrome and Firefox appear to tolerate the malformed output.

## Notes

- The bug does **not** reproduce with a minimal isolated input — it is triggered by Rolldown merging multiple module-level `var` declarations across bundled modules before applying the loop optimization.
- Related closed issue: [rolldown/rolldown#8146](https://github.com/rolldown/rolldown/issues/8146) — "Minifier incorrectly merges statements into for-in expression via comma operator"

## Workaround

Add to `vite.config.mts`:

```ts
build: {
  minify: "esbuild",
},
```

esbuild correctly outputs `for(;Dt in globalThis;)Dt=\`$ark${za++}\``.