# Migrating Import Sorting to oxfmt

2025-12-30

We've been using the Prettier `@ianvs/prettier-plugin-sort-imports` plugin to keep imports organized. oxfmt is a new member of the Oxc family of Rust based JavaScript tools, and now ships with `experimentalSortImports`—heavily inspired by `eslint-plugin-perfectionist`—and I wanted to see if we could make the move.

**Short answer: almost.** There's one blocker for monorepo setups that separate company packages from app-local imports.

## The Migration

**Before** (prettier.config.js):

```js
const config = {
  plugins: [
    "@ianvs/prettier-plugin-sort-imports",
    "prettier-plugin-packagejson",
  ],
  importOrder: [
    "<BUILT_IN_MODULES>",
    "",
    "<THIRD_PARTY_MODULES>",
    "",
    "^@acme/(.*)$",
    "",
    "^~/(.*)$",
    "",
    "^[./]",
  ],
};
```

**After** (.oxfmtrc.json):

```json
{
  "experimentalSortImports": {
    "groups": [
      "builtin",
      "external",
      "internal",
      ["parent", "sibling", "index"]
    ],
    "internalPattern": ["@acme/", "~/"],
    "newlinesBetween": true
  }
}
```

The `prettier-plugin-packagejson` functionality is built-in via `experimentalSortPackageJson` (enabled by default).

## The Gotcha: Prefix Matching, Not Regex

oxfmt's `internalPattern` uses **simple prefix matching**. Your regex patterns won't work:

| Plugin pattern | oxfmt equivalent |
|----------------|------------------|
| `^@acme/(.*)$` | `@acme/` |
| `^~/(.*)$` | `~/` |

This is a conscious design choice. The oxfmt author [did a code search](https://github.com/search?q=%22internalPattern%3A+%5B%22&type=code) and found most real-world usage is just prefixes anyway. Fair enough.

## The "Blocker": No Custom Group Separation

Here's what we can't do yet:

```js
// Our current setup separates these into distinct groups:
importOrder: [
  "^@acme/(.*)$",  // Company packages (group 1)
  "",
  "^~/(.*)$",      // App-local imports (group 2)
]
```

With oxfmt, both `@acme/` and `~/` imports get squashed into a single "internal" group. They'll be sorted alphabetically together—no blank line between them.

The `customGroups` feature that would fix this is [tracked in Phase 2](https://github.com/oxc-project/oxc/issues/14253), awaiting feedback. If you need this, go comment on the issue.

---

### Links

- [oxfmt experimentalSortImports tracking issue](https://github.com/oxc-project/oxc/issues/14253)
- [eslint-plugin-perfectionist docs](https://perfectionist.dev/rules/sort-imports) (oxfmt's inspiration)
- [@ianvs/prettier-plugin-sort-imports](https://github.com/IanVS/prettier-plugin-sort-imports)