vite-plugin-unused-code/README.md

Vite/Rollup plugin to detect unused files and unused exports in used files

# vite-plugin-unused-code

[![npm](https://img.shields.io/npm/v/vite-plugin-unused-code.svg)](https://www.npmjs.com/package/vite-plugin-unused-code)

Vite/Rollup plugin to detect unused files and unused exports in used files.

This package is a ported version of [`webpack-deadcode-plugin`](https://github.com/MQuy/webpack-deadcode-plugin).

> [!IMPORTANT]
> This plugin cannot check for dependencies of **non-JavaScript files or exports (for example: CSS, or types from TypeScript files)**, which may be misreported as unused, even if they actually appear in the compiled bundles. **Please be careful!**

> [!WARNING]
> Rolldown does not report removed exports during tree shaking currently. Therefore, **unused exports will never be reported in Vite 8 or higher.**

## Installation

```shell
npm install --save-dev vite-plugin-unused-code
```

## Usage

```js
// vite.config.js
import unusedCode from 'vite-plugin-unused-code'

export default {
  plugins: [
    unusedCode({
      patterns: ['src/**/*.*'],
    }),
  ],
}
```

## Options

### `context`

- **Type:** `string`
- **Default:** `root` option of Vite, `process.cwd()` as a fallback

  Current working directory where `patterns` and `exclude` are located.

### `patterns`

- **Type:** `string[]`
- **Default:** `['**/*.*']`

  The array of [`micromatch`](https://github.com/micromatch/micromatch) patterns to look for unused files and unused export in used files.

### `exclude`

- **Type:** `string[]`
- **Default:** `[]`

  *Deprecated*. The array of patterns to not look at. `{ exclude: ['foo'] }` is actually equivalent to `{ patterns: ['!foo'] }`.

  This option is reserved only for compatibility with `webpack-deadcode-plugin`.

### `detectUnusedFiles`

- **Type:** `boolean`
- **Default:** `true`

  Whether to run unused files detection or not.

### `detectUnusedExport`

- **Type:** `boolean`
- **Default:** `true`

  Whether to run unused export detection in used files or not.

### `log`

- **Type:** `'all' | 'unused' | 'none'`
- **Default:** `none` if `logLevel` option of Vite is `'silent'`, `'unused'` if `logLevel` option of Vite is `'error'` or `'warn'`, `'all'` otherwise

  Adjust console output verbosity.

  - `'all'`: Show all messages.
  - `'unused'`: Only show messages when there are either unused files or unused export.
  - `'none'`: Won't show unused files or unused export messages in the console. It can keep terminal clean when set `exportJSON` to `true`.

### `exportJSON`

- **Type:** `boolean | string`
- **Default:** `false`

  Whether to export data in JSON format. A `unused-code.json` file will be created in the current directory is specified as `true`. You can also specify a directory to create in it instead.

### `failOnHint`

- **Type:** `boolean`
- **Default:** `false`

  Whether to interrupt the compilation when unused files or exports detected.