Use Import Meta Dirname

Replace __dirname with import.meta.dirname in Vite config files

Vite 8 warns when a config uses features that its configLoader: 'native' mode cannot support, and __dirname is one of them:

(!) Your Vite config uses features that are unsupported by `configLoader: 'native'`, which is planned to become the default in a future major version of Vite:
  - `__dirname` (packages/utils/vitest.config.mts:4:9). Use `import.meta.dirname` instead

This migration rewrites __dirname to import.meta.dirname in every vite.config.mts, vite.config.mjs, vitest.config.mts, and vitest.config.mjs file in your workspace.

Sample Code Changes

Before

export default defineConfig(() => ({
  root: __dirname,
}));

After

export default defineConfig(() => ({
  root: import.meta.dirname,
}));

What is not rewritten

.ts and .js configs are left alone, since those extensions can still be loaded as CommonJS, where import.meta is a syntax error. Configs that declare their own __dirname (usually const __dirname = path.dirname(fileURLToPath(import.meta.url))) are also left alone - that idiom already works under the native config loader.

No migration renames an existing config to .mts, because other tooling may reference it by path. So a workspace whose config is .ts keeps the companion warning about ESM syntax in a CommonJS-loaded file. Rename it yourself, or set "type": "module" in the closest package.json, to clear that one. Newly generated configs use .mts and are unaffected.

One generated case does put import.meta.dirname in a .ts config: @nx/nuxt falls back to .ts on workspaces still using eslintrc, because the legacy @nuxt/eslint-config cannot parse .mts. Vite's default config loader bundles that file, so it works today, but the file is not loadable under configLoader: 'native' - its own import statements already make it so.