feat: support dprint

Author: antfu

README.md

@@ -6,7 +6,77 @@
 [![JSDocs][jsdocs-src]][jsdocs-href]
 [![License][license-src]][license-href]
 
-Plain text formatters integration for ESLint.
+Format various languages with formatters in ESLint. Supports [Prettier](https://prettier.io/) and [dprint](https://dprint.dev/). Side-effects-free and fully configurable.
+
+## Usages
+
+### Install
+
+```bash
+npm i -D eslint-plugin-format
+```
+
+### Configure
+
+This plugin does not do language detection or reading configure files, you need to specify the language for each file type you want to format along with other formatting options. We recommend using [ESLint's Flat Config format](https://eslint.org/docs/latest/use/configure/configuration-files-new).
+
+```ts
+// eslint.config.js
+import format from 'eslint-plugin-format'
+
+export default [
+  // ...other flat configs
+
+  // use Prettier to format CSS
+  {
+    files: ['**/*.css'],
+    languageOptions: {
+      parser: format.parserPlain,
+    },
+    plugins: {
+      format,
+    },
+    rules: {
+      'format/prettier': ['error', { parser: 'css', tabWidth: 2 }],
+    },
+  },
+
+  // use dprint to format TOML
+  {
+    files: ['**/*.toml'],
+    languageOptions: {
+      parser: format.parserPlain,
+    },
+    plugins: {
+      format,
+    },
+    rules: {
+      'format/dprint': ['error', { language: 'toml', languageOptions: { indentWidth: 2 } }],
+    },
+  },
+]
+```
+
+## Rules
+
+### `format/prettier`
+
+Use Prettier to format files.
+
+#### Options
+
+- `parser` (required) - the language to format, [Supported languages](https://prettier.io/docs/en/options.html#parser)
+- The rest options are passed as Prettier options
+
+### `format/dprint`
+
+Use dprint to format files.
+
+#### Options
+
+- `language` (required) - the language to format, or can be a filepath or URL to the WASM binary. [Supported languages](https://dprint.dev/plugins/)
+- `languageOptions` - the options for the language
+- The rest options are passed as dprint's general options
 
 ## Sponsors
 
@@ -16,6 +86,19 @@ Plain text formatters integration for ESLint.
   </a>
 </p>
 
+## FAQ
+
+### What's the difference between this and `eslint-plugin-prettier`?
+
+While this plugin provides Prettier as one of the formatters, the main difference is that `eslint-plugin-prettier` is much more opinionated toward the Prettier CLI ecosystem. While this plugin only treats Prettier as the side-effects-free formatter and gives you full control in ESLint.
+
+## Credits
+
+Thanks to the existing works for references and inspiration.
+
+- [eslint-plugin-prettier](https://github.com/prettier/eslint-plugin-prettier)
+- [eslint-plugin-dprint-integration](https://github.com/so1ve/eslint-plugin-dprint-integration)
+
 ## License
 
 [MIT](./LICENSE) License © 2023-PRESENT [Anthony Fu](https://github.com/antfu)

dts/define-config-support.d.ts

@@ -0,0 +1,7 @@
+import type { RuleOptions } from './rule-options'
+
+declare module 'eslint-define-config' {
+  export interface CustomRuleOptions extends RuleOptions {}
+}
+
+export {}

dts/rule-options.d.ts

@@ -0,0 +1,14 @@
+import type { Options as PrettierOptions } from 'prettier'
+
+export interface RuleOptions {
+  'format/prettier': [PrettierOptions]
+  'format/dprint': [DprintOptions]
+}
+
+export { PrettierOptions }
+
+export interface DprintOptions {
+  language: string
+  languageOptions?: Record<string, unknown>
+  [x: string]: unknown
+}

eslint.config.js

@@ -1,19 +1,31 @@
 // @ts-check
 import antfu from '@antfu/eslint-config'
-import formatters from 'eslint-plugin-format'
+import format from 'eslint-plugin-format'
 
 export default antfu(
   {},
   {
     files: ['**/*.css'],
     languageOptions: {
-      parser: formatters.parserPlain,
+      parser: format.parserPlain,
     },
     plugins: {
-      formatters,
+      format,
     },
     rules: {
-      'formatters/prettier': ['error', { parser: 'css' }],
+      'format/prettier': ['error', { parser: 'css' }],
+    },
+  },
+  {
+    files: ['**/*.toml'],
+    languageOptions: {
+      parser: format.parserPlain,
+    },
+    plugins: {
+      format,
+    },
+    rules: {
+      'format/dprint': ['error', { language: 'toml' }],
     },
   },
 )

examples/foo.toml

@@ -0,0 +1,2 @@
+[foo]
+a = 1

examples/style.css

@@ -0,0 +1,3 @@
+.foo {
+  color: green;
+}

package.json

@@ -3,7 +3,7 @@
   "type": "module",
   "version": "0.0.0",
   "packageManager": "[email protected]",
-  "description": "_description_",
+  "description": "Format various languages with formatters in ESLint",
   "author": "Anthony Fu <[email protected]>",
   "license": "MIT",
   "funding": "https://github.com/sponsors/antfu",
@@ -13,13 +13,25 @@
     "url": "git+https://github.com/antfu/eslint-plugin-format.git"
   },
   "bugs": "https://github.com/antfu/eslint-plugin-format/issues",
-  "keywords": [],
+  "keywords": [
+    "eslint",
+    "eslint-plugin",
+    "formatters",
+    "prettier",
+    "dprint"
+  ],
   "sideEffects": false,
   "exports": {
     ".": {
       "types": "./dist/index.d.ts",
       "import": "./dist/index.mjs",
       "require": "./dist/index.cjs"
+    },
+    "./define-config-support": {
+      "types": "./dts/define-config-support.d.ts"
+    },
+    "./rule-options": {
+      "types": "./dts/rule-options.d.ts"
     }
   },
   "main": "./dist/index.mjs",
@@ -34,7 +46,9 @@
     }
   },
   "files": [
-    "dist"
+    "dist",
+    "dts",
+    "workers"
   ],
   "scripts": {
     "build": "unbuild",
@@ -51,6 +65,9 @@
     "eslint": "^8.40.0"
   },
   "dependencies": {
+    "@dprint/formatter": "^0.2.0",
+    "@dprint/markdown": "^0.16.3",
+    "@dprint/toml": "^0.5.4",
     "eslint-formatting-reporter": "^0.0.0",
     "eslint-parser-plain": "^0.1.0",
     "prettier": "^3.1.0",

pnpm-lock.yaml

@@ -1,9 +1,11 @@
 import * as parserPlain from 'eslint-parser-plain'
 import prettier from './rules/prettier'
+import dprint from './rules/dprint'
 
 export default {
   parserPlain,
   rules: {
     prettier,
+    dprint,
   },
 }

src/index.ts

@@ -0,0 +1,48 @@
+import { join } from 'node:path'
+import type { Rule } from 'eslint'
+import { createSyncFn } from 'synckit'
+import { messages, reportDifferences } from 'eslint-formatting-reporter'
+import { dirWorkers } from '../dir'
+import type { DprintOptions } from '../../dts/rule-options'
+
+let format: (code: string, filename: string, options: DprintOptions) => string
+
+export default {
+  meta: {
+    type: 'layout',
+    docs: {
+      description: 'Use dprint to format code',
+      category: 'Stylistic',
+    },
+    fixable: 'whitespace',
+    schema: [
+      {
+        type: 'object',
+        properties: {
+          language: {
+            type: 'string',
+            required: true,
+          },
+          languageOptions: {
+            type: 'object',
+          },
+        },
+        additionalProperties: true,
+      },
+    ],
+    messages,
+  },
+  create(context) {
+    if (!format)
+      format = createSyncFn(join(dirWorkers, 'dprint.cjs'))
+
+    return {
+      Program() {
+        const sourceCode = context.sourceCode.text
+        const formatted = format(sourceCode, context.filename, context.options[0] || {})
+
+        reportDifferences(context, sourceCode, formatted)
+      },
+    }
+  },
+} satisfies Rule.RuleModule

src/rules/dprint.ts

@@ -0,0 +1,49 @@
+const fs = require('node:fs/promises')
+const { Buffer } = require('node:buffer')
+const { runAsWorker } = require('synckit')
+
+let dprint
+const cache = new Map()
+
+async function loadBuffer(data) {
+  if (typeof data === 'string' && data.startsWith('@dprint/'))
+    data = await import(data).then(m => m.getBuffer?.() || m.getPath?.())
+
+  if (typeof data === 'string') {
+    if (data.startsWith('data:')) {
+      const [, base64] = data.split(',')
+      return Buffer.from(base64, 'base64')
+    }
+    else if (data.match(/^[\w-]+:\/\//)) {
+      return fetch(data).then(r => r.buffer())
+    }
+    else {
+      return fs.readFile(data)
+    }
+  }
+
+  return data
+}
+
+runAsWorker(async (code, filename, options) => {
+  if (!dprint)
+    dprint = await import('@dprint/formatter')
+
+  const builtInLangs = {
+    json: '@dprint/json',
+    toml: '@dprint/toml',
+    markdown: '@dprint/markdown',
+    typescript: '@dprint/typescript',
+    dockerfile: '@dprint/dockerfile',
+  }
+
+  const lang = builtInLangs[options.language] || options.language
+  const promise = cache.has(lang)
+    ? cache.get(lang)
+    : cache.set(lang, loadBuffer(lang).then(r => dprint.createFromBuffer(r))).get(lang)
+
+  const formatter = await promise
+  const { lang: _, languageOptions = {}, ...rest } = options
+  formatter.setConfig(rest, languageOptions)
+  return formatter.formatText(filename, code)
+})