feat!: change the plugin into an ESM-only package

Author: ota-meshi

.env-cmdrc.js

@@ -0,0 +1,14 @@
+{
+	"version": {
+		"IN_VERSION_SCRIPT": "true"
+	},
+	"version-ci": {
+		"IN_VERSION_CI_SCRIPT": "true"
+	},
+	"debug": {
+		"DEBUG": "eslint-plugin-svelte*"
+	},
+	"update-fixtures": {
+		"UPDATE_FIXTURES": "true"
+	}
+}

.env-cmdrc.json

@@ -0,0 +1,14 @@
+{
+	"version": {
+		"IN_VERSION_SCRIPT": "true"
+	},
+	"version-ci": {
+		"IN_VERSION_CI_SCRIPT": "true"
+	},
+	"debug": {
+		"DEBUG": "eslint-plugin-svelte*"
+	},
+	"update-fixtures": {
+		"UPDATE_FIXTURES": "true"
+	}
+}

packages/eslint-plugin-svelte/.env-cmdrc.js

@@ -10,7 +10,7 @@
   "engines": {
     "node": "^18.20.4 || ^20.18.0 || >=22.10.0"
   },
-  "type": "commonjs",
+  "type": "module",
   "main": "lib/index.js",
   "files": [
     "lib"
@@ -40,7 +40,7 @@
     "test": "pnpm run mocha \"tests/src/**/*.ts\" --reporter dot --timeout 60000",
     "test:debug": "env-cmd -e debug pnpm run test",
     "test:update-fixtures": "env-cmd -e update-fixtures pnpm run test",
-    "ts": "node -r esbuild-register",
+    "ts": "node --import tsx/esm",
     "typecov": "type-coverage",
     "update": "pnpm run ts ./tools/update.ts",
     "version": "env-cmd -e version pnpm run update",
@@ -63,7 +63,7 @@
     "known-css-properties": "^0.35.0",
     "postcss": "^8.4.49",
     "postcss-load-config": "^3.1.4",
-    "postcss-safe-parser": "^7.0.0",
+    "postcss-safe-parser": "^6.0.0",
     "postcss-selector-parser": "^7.0.0",
     "semver": "^7.6.3",
     "svelte-eslint-parser": "^1.0.0-next.1"
@@ -86,7 +86,6 @@
     "acorn": "^8.14.0",
     "assert": "^2.1.0",
     "esbuild": "^0.24.0",
-    "esbuild-register": "^3.6.0",
     "eslint-scope": "^8.2.0",
     "eslint-typegen": "^0.3.2",
     "eslint-visitor-keys": "^4.2.0",
@@ -100,6 +99,7 @@
     "stylus": "^0.64.0",
     "svelte": "^5.2.9",
     "svelte-i18n": "^4.0.1",
+    "tsx": "^4.19.2",
     "type-coverage": "^2.29.7",
     "yaml": "^2.6.1"
   },

packages/eslint-plugin-svelte/.env-cmdrc.json

@@ -1,6 +1,6 @@
 import type { Linter } from 'eslint';
-import { rules } from '../../utils/rules';
-import base from './base';
+import { rules } from '../../utils/rules.js';
+import base from './base.js';
 const config: Linter.Config[] = [
 	...base,
 	{

packages/eslint-plugin-svelte/babel.config.js renamed to packages/eslint-plugin-svelte/babel.config.cjs

@@ -2,22 +2,25 @@
 // This file has been automatically generated,
 // in order to update its content execute "pnpm run update"
 import type { ESLint, Linter } from 'eslint';
+import * as parser from 'svelte-eslint-parser';
+let pluginObject: ESLint.Plugin | null = null;
+export function setPluginObject(plugin: ESLint.Plugin): void {
+	pluginObject = plugin;
+}
 const config: Linter.Config[] = [
 	{
 		name: 'svelte:base:setup-plugin',
 		plugins: {
 			get svelte(): ESLint.Plugin {
-				// eslint-disable-next-line @typescript-eslint/no-require-imports -- ignore
-				return require('../../index');
+				return pluginObject!;
 			}
 		}
 	},
 	{
 		name: 'svelte:base:setup-for-svelte',
 		files: ['*.svelte', '**/*.svelte'],
 		languageOptions: {
-			// eslint-disable-next-line @typescript-eslint/no-require-imports -- ignore
-			parser: require('svelte-eslint-parser')
+			parser
 		},
 		rules: {
 			// ESLint core rules known to cause problems with `.svelte`.

packages/eslint-plugin-svelte/package.json

@@ -2,7 +2,7 @@
 // This file has been automatically generated,
 // in order to update its content execute "pnpm run update"
 import type { Linter } from 'eslint';
-import base from './base';
+import base from './base.js';
 const config: Linter.Config[] = [
 	...base,
 	{

packages/eslint-plugin-svelte/postcss.config.js renamed to packages/eslint-plugin-svelte/postcss.config.cjs

@@ -2,7 +2,7 @@
 // This file has been automatically generated,
 // in order to update its content execute "pnpm run update"
 import type { Linter } from 'eslint';
-import base from './base';
+import base from './base.js';
 const config: Linter.Config[] = [
 	...base,
 	{

packages/eslint-plugin-svelte/src/configs/all.ts

@@ -1,42 +1,44 @@
 import './rule-types';
-import type { RuleModule } from './types';
-import { rules as ruleList } from './utils/rules';
-import base from './configs/base';
-import recommended from './configs/recommended';
-import prettier from './configs/prettier';
-import all from './configs/all';
-import flatBase from './configs/flat/base';
-import flatRecommended from './configs/flat/recommended';
-import flatPrettier from './configs/flat/prettier';
-import flatAll from './configs/flat/all';
-import * as processor from './processor';
-import * as meta from './meta';
+import type { RuleModule } from './types.js';
+import { rules as ruleList } from './utils/rules.js';
+import base, { setPluginObject } from './configs/flat/base.js';
+import recommended from './configs/flat/recommended.js';
+import prettier from './configs/flat/prettier.js';
+import all from './configs/flat/all.js';
+import * as processor from './processor/index.js';
+import * as meta from './meta.js';
 
-const configs = {
+export const configs = {
 	base,
 	recommended,
 	prettier,
 	all,
-	'flat/base': flatBase,
-	'flat/recommended': flatRecommended,
-	'flat/prettier': flatPrettier,
-	'flat/all': flatAll
+	// For backward compatibility
+	'flat/base': base,
+	'flat/recommended': recommended,
+	'flat/prettier': prettier,
+	'flat/all': all
 };
 
-const rules = ruleList.reduce(
+export const rules = ruleList.reduce(
 	(obj, r) => {
 		obj[r.meta.docs.ruleName] = r;
 		return obj;
 	},
 	{} as { [key: string]: RuleModule }
 );
 
-export = {
-	meta,
-	configs,
+export { meta };
+export const processors = {
+	'.svelte': processor,
+	svelte: processor
+};
+
+const plugin = {
 	rules,
-	processors: {
-		'.svelte': processor,
-		svelte: processor
-	}
+	configs,
+	meta,
+	processors
 };
+setPluginObject(plugin as never);
+export default plugin;

packages/eslint-plugin-svelte/src/configs/base.ts

@@ -1,7 +1,7 @@
 import type { Linter } from 'eslint';
-import type { Shared } from '../shared';
-import { beginShared, terminateShared } from '../shared';
-export * as meta from '../meta';
+import type { Shared } from '../shared/index.js';
+import { beginShared, terminateShared } from '../shared/index.js';
+export * as meta from '../meta.js';
 
 /** preprocess */
 export function preprocess(code: string, filename: string): string[] {

packages/eslint-plugin-svelte/src/configs/flat/all.ts

@@ -3,7 +3,7 @@
 // https://github.com/typescript-eslint/typescript-eslint/blob/main/packages/eslint-plugin/src/rules/no-unnecessary-condition.ts
 import type { TSESTree } from '@typescript-eslint/types';
 import type { AST } from 'svelte-eslint-parser';
-import { createRule } from '../../utils';
+import { createRule } from '../../utils/index.js';
 import {
 	isFalsyType,
 	getConstrainedTypeAtLocation,
@@ -20,9 +20,9 @@ import {
 	getTypeOfPropertyOfType,
 	getTypeName,
 	isTupleType
-} from '../../utils/ts-utils';
-import type { TS, TSTools } from '../../utils/ts-utils';
-import { getSourceCode } from '../../utils/compat';
+} from '../../utils/ts-utils/index.js';
+import type { TS, TSTools } from '../../utils/ts-utils/index.js';
+import { getSourceCode } from '../../utils/compat.js';
 
 /**
  * Returns all types of a union type or an array containing `type` itself if it's no union type.

packages/eslint-plugin-svelte/src/configs/flat/base.ts

@@ -1,7 +1,7 @@
-import { createRule } from '../utils';
-import { getLangValue } from '../utils/ast-utils';
+import { createRule } from '../utils/index.js';
+import { getLangValue } from '../utils/ast-utils.js';
 import type { SvelteScriptElement, SvelteStyleElement } from 'svelte-eslint-parser/lib/ast';
-import { getSourceCode } from '../utils/compat';
+import { getSourceCode } from '../utils/compat.js';
 
 export default createRule('block-lang', {
 	meta: {