feat: introduce tsdown, support mixed js & ts in codebase

.gitignore

@@ -14,3 +14,4 @@ yarn-error.log
 /docs/.vitepress/cache
 typings/eslint/lib/rules
 eslint-typegen.d.ts
+dist

docs/.vitepress/theme/components/eslint-code-block.vue

@@ -142,7 +142,7 @@ export default {
     this.height = `${Math.max(120, 20 * (1 + lines))}px`
     // Load linter.
     const [plugin, { Linter }, vueEslintParser, globals] = await Promise.all([
-      import('../../../..'),
+      import('../../../../lib/index'),
       import('eslint'),
       import('vue-eslint-parser'),
       import('globals')

eslint.config.mjs

@@ -49,6 +49,7 @@ const MD_LINKS_FOR_DOCS = {
 export default typegen([
   {
     ignores: [
+      'dist',
       '.nyc_output',
       'coverage',
       'node_modules',

lib/meta.ts

@@ -0,0 +1,3 @@
+import { name, version } from '../package.json' with { type: 'json' }
+
+export { name, version }

lib/processor.js → lib/processor.ts

@@ -1,44 +1,33 @@
 /**
  * @author Toru Nagashima <https://github.com/mysticatea>
  */
-'use strict'
+import type { Linter } from 'eslint'
 
-/**
- * @typedef {import('eslint').Linter.LintMessage} LintMessage
- */
-/**
- * @typedef {object} GroupState
- * @property {Set<string>} GroupState.disableAllKeys
- * @property {Map<string, string[]>} GroupState.disableRuleKeys
- */
+type LintMessage = Linter.LintMessage
+
+interface GroupState {
+  disableAllKeys: Set<string>
+  disableRuleKeys: Map<string, string[]>
+}
 
-module.exports = {
-  /** @param {string} code */
-  preprocess(code) {
+export default {
+  preprocess(code: string): string[] {
     return [code]
   },
 
-  /**
-   * @param {LintMessage[][]} messages
-   * @returns {LintMessage[]}
-   */
-  postprocess(messages) {
+  postprocess(messages: LintMessage[][]): LintMessage[] {
     const state = {
-      /** @type {GroupState} */
       block: {
-        disableAllKeys: new Set(),
-        disableRuleKeys: new Map()
-      },
-      /** @type {GroupState} */
+        disableAllKeys: new Set<string>(),
+        disableRuleKeys: new Map<string, string[]>()
+      } satisfies GroupState,
       line: {
-        disableAllKeys: new Set(),
-        disableRuleKeys: new Map()
-      }
+        disableAllKeys: new Set<string>(),
+        disableRuleKeys: new Map<string, string[]>()
+      } satisfies GroupState
     }
-    /** @type {string[]} */
-    const usedDisableDirectiveKeys = []
-    /** @type {Map<string,LintMessage>} */
-    const unusedDisableDirectiveReports = new Map()
+    const usedDisableDirectiveKeys: string[] = []
+    const unusedDisableDirectiveReports = new Map<string, LintMessage>()
 
     // Filter messages which are in disabled area.
     const filteredMessages = messages[0].filter((message) => {
@@ -139,12 +128,11 @@ module.exports = {
   meta: require('./meta')
 }
 
-/**
- * @param {Map<string, string[]>} disableRuleKeys
- * @param {string} rule
- * @param {string} key
- */
-function addDisableRule(disableRuleKeys, rule, key) {
+function addDisableRule(
+  disableRuleKeys: GroupState['disableRuleKeys'],
+  rule: string,
+  key: string
+): void {
   let keys = disableRuleKeys.get(rule)
   if (keys) {
     keys.push(key)
@@ -154,11 +142,7 @@ function addDisableRule(disableRuleKeys, rule, key) {
   }
 }
 
-/**
- * @param {LintMessage} message
- * @returns {string} message key
- */
-function messageToKey(message) {
+function messageToKey(message: LintMessage): string {
   return `line:${message.line},column${
     // -1 because +1 by ESLint's `report-translator`.
     message.column - 1
@@ -167,11 +151,11 @@ function messageToKey(message) {
 
 /**
  * Compares the locations of two objects in a source file
- * @param {Position} itemA The first object
- * @param {Position} itemB The second object
- * @returns {number} A value less than 1 if itemA appears before itemB in the source file, greater than 1 if
+ * @param itemA The first object
+ * @param itemB The second object
+ * @returns A value less than 1 if itemA appears before itemB in the source file, greater than 1 if
  * itemA appears after itemB in the source file, or 0 if itemA and itemB have the same location.
  */
-function compareLocations(itemA, itemB) {
+function compareLocations(itemA: Position, itemB: Position): number {
   return itemA.line - itemB.line || itemA.column - itemB.column
 }

package.json

@@ -2,8 +2,8 @@
   "name": "eslint-plugin-vue",
   "version": "10.4.0",
   "description": "Official ESLint plugin for Vue.js",
-  "main": "lib/index.js",
-  "types": "lib/index.d.ts",
+  "main": "dist/index.js",
+  "types": "dist/index.d.ts",
   "scripts": {
     "new": "node tools/new-rule.js",
     "start": "npm run test:base -- --watch --growl",
@@ -22,15 +22,17 @@
     "update": "node ./tools/update.js",
     "update-resources": "node ./tools/update-resources.js",
     "typegen": "node ./tools/generate-typegen.mjs",
+    "build": "tsdown",
     "docs:watch": "vitepress dev docs",
     "predocs:build": "npm run update",
     "docs:build": "vitepress build docs",
     "generate:version": "env-cmd -e version npm run update && npm run lint -- --fix",
     "changeset:version": "changeset version && npm run generate:version && git add --all",
-    "changeset:publish": "npm run typegen && changeset publish"
+    "changeset:publish": "npm run typegen && changeset publish",
+    "prepublishOnly": "npm run build"
   },
   "files": [
-    "lib"
+    "dist"
   ],
   "homepage": "https://eslint.vuejs.org",
   "keywords": [
@@ -115,6 +117,7 @@
     "markdownlint-cli": "^0.42.0",
     "pathe": "^1.1.2",
     "prettier": "^3.3.3",
+    "tsdown": "^0.14.1",
     "typescript": "^5.7.2",
     "vite-plugin-eslint4b": "^0.5.1",
     "vitepress": "^1.4.1",

tsconfig.json

@@ -1,8 +1,8 @@
 {
   "compilerOptions": {
-    "target": "ES2019",
-    "module": "node16",
-    "moduleResolution": "Node16",
+    "target": "esnext",
+    "module": "preserve",
+    "moduleResolution": "bundler",
     "lib": ["es2020"],
     "allowJs": true,
     "checkJs": true,
@@ -17,6 +17,8 @@
     "noFallthroughCasesInSwitch": true,
     "esModuleInterop": true,
     "resolveJsonModule": true,
+    "isolatedModules": true,
+    "noUncheckedSideEffectImports": true,
     "baseUrl": ".",
     "paths": {
       "*": ["typings/*"]

tsdown.config.ts

@@ -0,0 +1,11 @@
+import { defineConfig } from 'tsdown'
+
+export default defineConfig({
+  target: 'node18',
+  entry: ['lib/index.js'],
+  format: ['cjs'],
+  copy: ['lib/index.d.ts'],
+  dts: false,
+  external: ['typescript'],
+  unbundle: true
+})