diff --git a/.changeset/quick-beers-reflect.md b/.changeset/quick-beers-reflect.md
new file mode 100644
index 00000000..8367d818
--- /dev/null
+++ b/.changeset/quick-beers-reflect.md
@@ -0,0 +1,5 @@
+---
+"svelte-eslint-parser": major
+---
+
+feat!: change the parser to an ESM-only package
diff --git a/README.md b/README.md
index f9a55fdd..494035db 100644
--- a/README.md
+++ b/README.md
@@ -8,8 +8,6 @@ You can check it on [Online DEMO](https://sveltejs.github.io/svelte-eslint-parse
 > Please refer to the README for the version you are using.\
 > For example, <https://github.com/sveltejs/svelte-eslint-parser/blob/v0.43.0/README.md>
 
-**_Note that this parser has experimental support for Svelte v5, but may break with new versions of Svelte v5._**
-
 [![NPM license](https://img.shields.io/npm/l/svelte-eslint-parser.svg)](https://www.npmjs.com/package/svelte-eslint-parser)
 [![NPM version](https://img.shields.io/npm/v/svelte-eslint-parser.svg)](https://www.npmjs.com/package/svelte-eslint-parser)
 [![NPM downloads](https://img.shields.io/badge/dynamic/json.svg?label=downloads&colorB=green&suffix=/day&query=$.downloads&uri=https://api.npmjs.org//downloads/point/last-day/svelte-eslint-parser&maxAge=3600)](http://www.npmtrends.com/svelte-eslint-parser)
@@ -41,12 +39,6 @@ It provides many unique check rules by using the template AST.
 ESLint plugin for internationalization (i18n) with Svelte.  
 It provides rules to help internationalization your application created with Svelte.
 
-## ❗ Attention
-
-The [svelte-eslint-parser] can not be used with the [eslint-plugin-svelte3].
-
-[svelte-eslint-parser]: https://github.com/sveltejs/svelte-eslint-parser
-
 ## 💿 Installation
 
 ```bash
@@ -74,20 +66,6 @@ export default [
 ];
 ```
 
-### ESLint Config (`.eslintrc.*`)
-
-```json
-{
-  "extends": "eslint:recommended",
-  "overrides": [
-    {
-      "files": ["*.svelte"],
-      "parser": "svelte-eslint-parser"
-    }
-  ]
-}
-```
-
 ### CLI
 
 ```console
@@ -101,18 +79,26 @@ $ eslint src --ext .svelte
 [`parserOptions`] has the same properties as what [espree](https://github.com/eslint/espree#usage), the default parser of ESLint, is supporting.
 For example:
 
-```json
-{
-  "parserOptions": {
-    "sourceType": "module",
-    "ecmaVersion": 2021,
-    "ecmaFeatures": {
-      "globalReturn": false,
-      "impliedStrict": false,
-      "jsx": false
-    }
-  }
-}
+```js
+import svelteParser from "svelte-eslint-parser";
+export default [
+  // ...
+  {
+    files: ["**/*.svelte", "*.svelte"],
+    languageOptions: {
+      parser: svelteParser,
+      parserOptions: {
+        sourceType: "module",
+        ecmaVersion: 2021,
+        ecmaFeatures: {
+          globalReturn: false,
+          impliedStrict: false,
+          jsx: false,
+        },
+      },
+    },
+  },
+];
 ```
 
 [`parserOptions`]: https://eslint.org/docs/latest/use/configure/parser#configure-parser-options
@@ -139,17 +125,6 @@ export default [
 ];
 ```
 
-For example in `.eslintrc.*`:
-
-```json
-{
-  "parser": "svelte-eslint-parser",
-  "parserOptions": {
-    "parser": "@typescript-eslint/parser"
-  }
-}
-```
-
 If you are using the `"@typescript-eslint/parser"`, and if you want to use TypeScript in `<script>` of `.svelte`, you need to add more `parserOptions` configuration.
 
 For example in `eslint.config.js`:
@@ -183,32 +158,6 @@ export default [
 ];
 ```
 
-For example in `.eslintrc.*`:
-
-```js
-module.exports = {
-  // ...
-  parser: "@typescript-eslint/parser",
-  parserOptions: {
-    // ...
-    project: "path/to/your/tsconfig.json",
-    extraFileExtensions: [".svelte"], // This is a required setting in `@typescript-eslint/parser` v4.24.0.
-  },
-  overrides: [
-    {
-      files: ["*.svelte"],
-      parser: "svelte-eslint-parser",
-      // Parse the `<script>` in `.svelte` as TypeScript by adding the following configuration.
-      parserOptions: {
-        parser: "@typescript-eslint/parser",
-      },
-    },
-    // ...
-  ],
-  // ...
-};
-```
-
 #### Multiple parsers
 
 If you want to switch the parser for each lang, specify the object.
@@ -235,21 +184,6 @@ export default [
 ];
 ```
 
-For example in `.eslintrc.*`:
-
-```json
-{
-  "parser": "svelte-eslint-parser",
-  "parserOptions": {
-    "parser": {
-      "ts": "@typescript-eslint/parser",
-      "js": "espree",
-      "typescript": "@typescript-eslint/parser"
-    }
-  }
-}
-```
-
 ### parserOptions.svelteConfig
 
 If you are using `eslint.config.js`, you can provide a `svelte.config.js` in the `parserOptions.svelteConfig` property.
@@ -289,7 +223,6 @@ export default [
       parser: svelteParser,
       parserOptions: {
         svelteFeatures: {
-          /* It may be changed or removed in minor versions without notice. */
           // This option is for Svelte 5. The default value is `true`.
           // If `false`, ESLint will not recognize rune symbols.
           // If not configured this option, The parser will try to read the option from `compilerOptions.runes` from `svelte.config.js`.
@@ -302,28 +235,8 @@ export default [
 ];
 ```
 
-For example in `.eslintrc.*`:
-
-```jsonc
-{
-  "parser": "svelte-eslint-parser",
-  "parserOptions": {
-    "svelteFeatures": {
-      /* It may be changed or removed in minor versions without notice. */
-      // This option is for Svelte 5. The default value is `true`.
-      // If `false`, ESLint will not recognize rune symbols.
-      // If not configured this option, The parser will try to read the option from `compilerOptions.runes` from `svelte.config.js`.
-      // If `parserOptions.svelteConfig` is not specified and the file cannot be parsed by static analysis, it will behave as `true`.
-      "runes": true,
-    },
-  },
-}
-```
-
 ### Runes support
 
-**_This is an experimental feature. It may be changed or removed in minor versions without notice._**
-
 If you install Svelte v5 the parser will be able to parse runes, and will also be able to parse `*.js` and `*.ts` files.
 If you don't want to use Runes, you may need to configure. Please read [parserOptions.svelteFeatures](#parseroptionssveltefeatures) for more details.
 
@@ -369,38 +282,6 @@ export default [
 ];
 ```
 
-For example in `.eslintrc.*`:
-
-```jsonc
-{
-  "overrides": [
-    {
-      "files": ["*.svelte"],
-      "parser": "svelte-eslint-parser",
-      "parserOptions": {
-        "parser": "...",
-        /* ... */
-      },
-    },
-    {
-      "files": ["*.svelte.js"],
-      "parser": "svelte-eslint-parser",
-      "parserOptions": {
-        /* ... */
-      },
-    },
-    {
-      "files": ["*.svelte.ts"],
-      "parser": "svelte-eslint-parser",
-      "parserOptions": {
-        "parser": "...(ts parser)...",
-        /* ... */
-      },
-    },
-  ],
-}
-```
-
 ## :computer: Editor Integrations
 
 ### Visual Studio Code
@@ -439,4 +320,3 @@ See the [LICENSE](LICENSE) file for license rights and limitations (MIT).
 
 [Svelte]: https://svelte.dev/
 [ESLint]: https://eslint.org/
-[eslint-plugin-svelte3]: https://github.com/sveltejs/eslint-plugin-svelte3
diff --git a/benchmark/index.ts b/benchmark/index.ts
index 46b54fcd..6e23c845 100644
--- a/benchmark/index.ts
+++ b/benchmark/index.ts
@@ -2,8 +2,8 @@
 /* eslint-disable no-console -- ignore */
 import * as Benchmark from "benchmark";
 import fs from "fs";
-import { parseForESLint } from "../src/index";
-import { parseForESLint as parseOld } from "../node_modules/svelte-eslint-parser";
+import { parseForESLint } from "../src/index.js";
+import { parseForESLint as parseOld } from "../node_modules/svelte-eslint-parser/lib/index.js";
 
 const contents = `${fs.readFileSync(
   require.resolve("../explorer-v2/src/lib/RulesSettings.svelte"),
diff --git a/explorer-v2/build-system/shim/module.js b/explorer-v2/build-system/shim/module.js
index 5cb69b5f..a75de026 100644
--- a/explorer-v2/build-system/shim/module.js
+++ b/explorer-v2/build-system/shim/module.js
@@ -1,5 +1,15 @@
+// eslint-disable-next-line n/no-extraneous-import -- shim
+import * as estree from 'espree';
 export function createRequire() {
-	return null;
+	function req(mod) {
+		if (mod === 'espree') {
+			return estree;
+		}
+		throw new Error(`Cannot find module '${mod}'`);
+	}
+
+	req.cache = {};
+	return req;
 }
 export default {
 	createRequire
diff --git a/package.json b/package.json
index 3a2e1667..7b5aa89f 100644
--- a/package.json
+++ b/package.json
@@ -14,7 +14,7 @@
   "engines": {
     "node": "^18.20.4 || ^20.18.0 || >=22.10.0"
   },
-  "type": "commonjs",
+  "type": "module",
   "main": "lib/index.js",
   "files": [
     "lib"
@@ -30,8 +30,8 @@
     "build": "pnpm run build:meta && pnpm run build:tsc",
     "build:meta": "pnpm run ts ./tools/update-meta.ts",
     "build:tsc": "tsc --project ./tsconfig.build.json",
-    "clean": "rimraf .nyc_output lib coverage",
-    "cover": "nyc --reporter=lcov pnpm run test",
+    "clean": "rimraf lib coverage",
+    "cover": "c8 --reporter=lcov pnpm run test",
     "debug": "pnpm run mocha \"tests/src/**/*.ts\" --reporter dot --timeout 60000",
     "eslint-fix": "pnpm run lint --fix",
     "lint": "eslint .",
@@ -41,7 +41,7 @@
     "preversion": "pnpm run lint && pnpm run test",
     "release": "changeset publish",
     "test": "pnpm run mocha \"tests/src/**/*.ts\" --reporter dot --timeout 60000",
-    "ts": "node -r esbuild-register",
+    "ts": "node --import tsx/esm",
     "update-fixtures": "git add package.json && pnpm i -D svelte@4 && git checkout package.json && pnpm run run-update-fixtures && pnpm i && pnpm run run-update-fixtures",
     "run-update-fixtures": "pnpm run ts ./tools/update-fixtures.ts",
     "version:ci": "env-cmd -e version-ci pnpm run build:meta && changeset version"
@@ -79,10 +79,10 @@
     "@typescript-eslint/parser": "~8.16.0",
     "@typescript-eslint/types": "~8.16.0",
     "benchmark": "^2.1.4",
+    "c8": "^10.1.2",
     "chai": "^5.0.0",
     "env-cmd": "^10.1.0",
     "esbuild": "^0.24.0",
-    "esbuild-register": "^3.6.0",
     "eslint": "~9.16.0",
     "eslint-config-prettier": "^9.1.0",
     "eslint-plugin-eslint-comments": "^3.2.0",
@@ -100,7 +100,6 @@
     "magic-string": "^0.30.14",
     "mocha": "^10.8.2",
     "mocha-chai-jest-snapshot": "^1.1.6",
-    "nyc": "^17.1.0",
     "prettier": "~3.4.1",
     "prettier-plugin-pkg": "^0.18.1",
     "prettier-plugin-svelte": "^3.3.2",
@@ -108,6 +107,7 @@
     "semver": "^7.6.3",
     "svelte": "^5.3.1",
     "svelte2tsx": "^0.7.28",
+    "tsx": "^4.19.2",
     "typescript": "~5.7.2",
     "typescript-eslint": "^8.16.0",
     "typescript-eslint-parser-for-extra-files": "^0.7.0"
diff --git a/src/ast/base.ts b/src/ast/base.ts
index 9e931311..d231bd07 100644
--- a/src/ast/base.ts
+++ b/src/ast/base.ts
@@ -1,4 +1,4 @@
-import type { Locations } from "./common";
+import type { Locations } from "./common.js";
 
 // internals
 export interface BaseNode extends Locations {
diff --git a/src/ast/common.ts b/src/ast/common.ts
index 6d80cfb0..73727723 100644
--- a/src/ast/common.ts
+++ b/src/ast/common.ts
@@ -1,4 +1,4 @@
-import type { BaseNode } from "./base";
+import type { BaseNode } from "./base.js";
 
 export interface Position {
   /** >= 1 */
diff --git a/src/ast/html.ts b/src/ast/html.ts
index efbe8f85..c39f29e0 100644
--- a/src/ast/html.ts
+++ b/src/ast/html.ts
@@ -1,7 +1,7 @@
 import type ESTree from "estree";
 import type { TSESTree } from "@typescript-eslint/types";
-import type { BaseNode } from "./base";
-import type { Token, Comment } from "./common";
+import type { BaseNode } from "./base.js";
+import type { Token, Comment } from "./common.js";
 
 export type SvelteHTMLNode =
   | SvelteProgram
diff --git a/src/ast/index.ts b/src/ast/index.ts
index a271aaa3..84edca40 100644
--- a/src/ast/index.ts
+++ b/src/ast/index.ts
@@ -1,8 +1,8 @@
-import type { SvelteHTMLNode } from "./html";
-import type { SvelteScriptNode } from "./script";
+import type { SvelteHTMLNode } from "./html.js";
+import type { SvelteScriptNode } from "./script.js";
 
-export * from "./common";
-export * from "./html";
-export * from "./script";
+export * from "./common.js";
+export * from "./html.js";
+export * from "./script.js";
 
 export type SvelteNode = SvelteHTMLNode | SvelteScriptNode;
diff --git a/src/ast/script.ts b/src/ast/script.ts
index 5cbda4d3..328af5f5 100644
--- a/src/ast/script.ts
+++ b/src/ast/script.ts
@@ -1,5 +1,5 @@
 import type ESTree from "estree";
-import type { BaseNode } from "./base";
+import type { BaseNode } from "./base.js";
 
 export type SvelteScriptNode = SvelteReactiveStatement;
 
diff --git a/src/context/fix-locations.ts b/src/context/fix-locations.ts
index dd1154e1..f5055784 100644
--- a/src/context/fix-locations.ts
+++ b/src/context/fix-locations.ts
@@ -1,7 +1,7 @@
 import type * as ESTree from "estree";
-import type { Comment, Locations, Token } from "../ast";
-import type { Context } from ".";
-import { traverseNodes } from "../traverse";
+import type { Comment, Locations, Token } from "../ast/index.js";
+import type { Context } from "./index.js";
+import { traverseNodes } from "../traverse.js";
 
 /** Fix locations */
 export function fixLocations(
diff --git a/src/context/index.ts b/src/context/index.ts
index 9dc8de3c..6cda47c8 100644
--- a/src/context/index.ts
+++ b/src/context/index.ts
@@ -9,18 +9,18 @@ import type {
   SvelteSnippetBlock,
   SvelteStyleElement,
   Token,
-} from "../ast";
+} from "../ast/index.js";
 import type ESTree from "estree";
-import type * as SvAST from "../parser/svelte-ast-types";
-import type * as Compiler from "../parser/svelte-ast-types-for-v5";
-import { ScriptLetContext } from "./script-let";
-import { LetDirectiveCollections } from "./let-directive-collection";
-import { parseAttributes } from "../parser/html";
-import { sortedLastIndex } from "../utils";
+import type * as SvAST from "../parser/svelte-ast-types.js";
+import type * as Compiler from "../parser/svelte-ast-types-for-v5.js";
+import { ScriptLetContext } from "./script-let.js";
+import { LetDirectiveCollections } from "./let-directive-collection.js";
+import { parseAttributes } from "../parser/html.js";
+import { sortedLastIndex } from "../utils/index.js";
 import {
   isTypeScript,
   type NormalizedParserOptions,
-} from "../parser/parser-options";
+} from "../parser/parser-options.js";
 
 export class ScriptsSourceCode {
   private raw: string;
diff --git a/src/context/let-directive-collection.ts b/src/context/let-directive-collection.ts
index 6f205e38..6334af97 100644
--- a/src/context/let-directive-collection.ts
+++ b/src/context/let-directive-collection.ts
@@ -1,6 +1,6 @@
-import type { SvelteLetDirective, SvelteName } from "../ast";
+import type { SvelteLetDirective, SvelteName } from "../ast/index.js";
 import type * as ESTree from "estree";
-import type { ScriptLetBlockParam, ScriptLetCallback } from "./script-let";
+import type { ScriptLetBlockParam, ScriptLetCallback } from "./script-let.js";
 
 /** A class that collects pattern nodes for Let directives. */
 export class LetDirectiveCollection {
diff --git a/src/context/script-let.ts b/src/context/script-let.ts
index cfe9ac8e..443f271c 100644
--- a/src/context/script-let.ts
+++ b/src/context/script-let.ts
@@ -2,7 +2,7 @@ import type { ScopeManager, Scope } from "eslint-scope";
 import type * as ESTree from "estree";
 import type { TSESTree } from "@typescript-eslint/types";
 import type { Scope as TSScope } from "@typescript-eslint/scope-manager";
-import type { Context, ScriptsSourceCode } from ".";
+import type { Context, ScriptsSourceCode } from "./index.js";
 import type {
   Comment,
   SvelteEachBlock,
@@ -11,19 +11,19 @@ import type {
   SvelteNode,
   SvelteSnippetBlock,
   Token,
-} from "../ast";
-import type { ESLintExtendedProgram } from "../parser";
-import { getWithLoc } from "../parser/converts/common";
+} from "../ast/index.js";
+import type { ESLintExtendedProgram } from "../parser/index.js";
+import { getWithLoc } from "../parser/converts/common.js";
 import {
   getScopeFromNode,
   removeAllScopeAndVariableAndReference,
   removeIdentifierVariable,
   removeReference,
   removeScope,
-} from "../scope";
-import { getKeys, traverseNodes, getNodes } from "../traverse";
-import { UniqueIdGenerator } from "./unique";
-import { fixLocations } from "./fix-locations";
+} from "../scope/index.js";
+import { getKeys, traverseNodes, getNodes } from "../traverse.js";
+import { UniqueIdGenerator } from "./unique.js";
+import { fixLocations } from "./fix-locations.js";
 
 type TSAsExpression = {
   type: "TSAsExpression";
diff --git a/src/errors.ts b/src/errors.ts
index 65a28913..c6be5af8 100644
--- a/src/errors.ts
+++ b/src/errors.ts
@@ -1,4 +1,4 @@
-import type { Context } from "./context";
+import type { Context } from "./context/index.js";
 
 /**
  * Svelte parse errors.
diff --git a/src/index.ts b/src/index.ts
index 3cb39f11..588e0211 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,24 +1,2 @@
-import * as AST from "./ast";
-import { traverseNodes } from "./traverse";
-import { KEYS } from "./visitor-keys";
-import { ParseError } from "./errors";
-export {
-  parseForESLint,
-  type StyleContext,
-  type StyleContextNoStyleElement,
-  type StyleContextParseError,
-  type StyleContextSuccess,
-  type StyleContextUnknownLang,
-} from "./parser";
-export * as meta from "./meta";
-export { name } from "./meta";
-export type { SvelteConfig } from "./svelte-config";
-
-export { AST, ParseError };
-
-// Keys
-// eslint-disable-next-line @typescript-eslint/naming-convention -- ignore
-export const VisitorKeys = KEYS;
-
-// tools
-export { traverseNodes };
+export * from "./main.js";
+export * as default from "./main.js";
diff --git a/src/main.ts b/src/main.ts
new file mode 100644
index 00000000..c8227535
--- /dev/null
+++ b/src/main.ts
@@ -0,0 +1,24 @@
+import * as AST from "./ast/index.js";
+import { traverseNodes } from "./traverse.js";
+import { KEYS } from "./visitor-keys.js";
+import { ParseError } from "./errors.js";
+export {
+  parseForESLint,
+  type StyleContext,
+  type StyleContextNoStyleElement,
+  type StyleContextParseError,
+  type StyleContextSuccess,
+  type StyleContextUnknownLang,
+} from "./parser/index.js";
+export * as meta from "./meta.js";
+export { name } from "./meta.js";
+export type { SvelteConfig } from "./svelte-config/index.js";
+
+export { AST, ParseError };
+
+// Keys
+// eslint-disable-next-line @typescript-eslint/naming-convention -- ignore
+export const VisitorKeys = KEYS;
+
+// tools
+export { traverseNodes };
diff --git a/src/parser/analyze-scope.ts b/src/parser/analyze-scope.ts
index caa384c6..b502b034 100644
--- a/src/parser/analyze-scope.ts
+++ b/src/parser/analyze-scope.ts
@@ -1,16 +1,16 @@
 import type ESTree from "estree";
 import type { Scope, ScopeManager } from "eslint-scope";
 import { Variable, Reference, analyze } from "eslint-scope";
-import { getFallbackKeys } from "../traverse";
+import { getFallbackKeys } from "../traverse.js";
 import type {
   SvelteReactiveStatement,
   SvelteScriptElement,
   SvelteSnippetBlock,
-} from "../ast";
-import { addReference, addVariable, getScopeFromNode } from "../scope";
-import { addElementToSortedArray } from "../utils";
-import type { NormalizedParserOptions } from "./parser-options";
-import type { SvelteParseContext } from "./svelte-parse-context";
+} from "../ast/index.js";
+import { addReference, addVariable, getScopeFromNode } from "../scope/index.js";
+import { addElementToSortedArray } from "../utils/index.js";
+import type { NormalizedParserOptions } from "./parser-options.js";
+import type { SvelteParseContext } from "./svelte-parse-context.js";
 /**
  * Analyze scope
  */
diff --git a/src/parser/compat.ts b/src/parser/compat.ts
index 7aa30d7f..535c8821 100644
--- a/src/parser/compat.ts
+++ b/src/parser/compat.ts
@@ -1,7 +1,7 @@
 /** Compatibility for Svelte v4 <-> v5 */
 import type ESTree from "estree";
-import type * as SvAST from "./svelte-ast-types";
-import type * as Compiler from "./svelte-ast-types-for-v5";
+import type * as SvAST from "./svelte-ast-types.js";
+import type * as Compiler from "./svelte-ast-types-for-v5.js";
 
 export type Child =
   | Compiler.Text
diff --git a/src/parser/converts/attr.ts b/src/parser/converts/attr.ts
index bc7dc3d2..e306b682 100644
--- a/src/parser/converts/attr.ts
+++ b/src/parser/converts/attr.ts
@@ -20,19 +20,19 @@ import type {
   SvelteStyleElement,
   SvelteElseBlock,
   SvelteAwaitBlock,
-} from "../../ast";
+} from "../../ast/index.js";
 import type ESTree from "estree";
-import type { Context } from "../../context";
-import type * as SvAST from "../svelte-ast-types";
-import type * as Compiler from "../svelte-ast-types-for-v5";
-import { getWithLoc, indexOf } from "./common";
-import { convertMustacheTag } from "./mustache";
-import { convertTextToLiteral } from "./text";
-import { ParseError } from "../../errors";
-import type { ScriptLetCallback } from "../../context/script-let";
-import { svelteVersion } from "../svelte-version";
-import { hasTypeInfo } from "../../utils";
-import { getModifiers } from "../compat";
+import type { Context } from "../../context/index.js";
+import type * as SvAST from "../svelte-ast-types.js";
+import type * as Compiler from "../svelte-ast-types-for-v5.js";
+import { getWithLoc, indexOf } from "./common.js";
+import { convertMustacheTag } from "./mustache.js";
+import { convertTextToLiteral } from "./text.js";
+import { ParseError } from "../../errors.js";
+import type { ScriptLetCallback } from "../../context/script-let.js";
+import { svelteVersion } from "../svelte-version.js";
+import { hasTypeInfo } from "../../utils/index.js";
+import { getModifiers } from "../compat.js";
 
 type LetDirective = Omit<Compiler.LetDirective, "expression"> & {
   expression: SvAST.LetDirective["expression"];
diff --git a/src/parser/converts/block.ts b/src/parser/converts/block.ts
index 274b2df6..5ad1f310 100644
--- a/src/parser/converts/block.ts
+++ b/src/parser/converts/block.ts
@@ -1,5 +1,5 @@
-import type * as SvAST from "../svelte-ast-types";
-import type * as Compiler from "../svelte-ast-types-for-v5";
+import type * as SvAST from "../svelte-ast-types.js";
+import type * as Compiler from "../svelte-ast-types-for-v5.js";
 import type {
   SvelteAwaitBlock,
   SvelteAwaitBlockAwaitCatch,
@@ -16,10 +16,10 @@ import type {
   SvelteIfBlockElseIf,
   SvelteKeyBlock,
   SvelteSnippetBlock,
-} from "../../ast";
-import type { Context } from "../../context";
-import { convertChildren } from "./element";
-import { getWithLoc, indexOf, lastIndexOf } from "./common";
+} from "../../ast/index.js";
+import type { Context } from "../../context/index.js";
+import { convertChildren } from "./element.js";
+import { getWithLoc, indexOf, lastIndexOf } from "./common.js";
 import type * as ESTree from "estree";
 import {
   getAlternateFromIfBlock,
@@ -33,7 +33,7 @@ import {
   getTestFromIfBlock,
   getThenFromAwaitBlock,
   trimChildren,
-} from "../compat";
+} from "../compat.js";
 
 /** Get start index of block */
 function startBlockIndex(
diff --git a/src/parser/converts/const.ts b/src/parser/converts/const.ts
index c236ae1c..d3c4a5d3 100644
--- a/src/parser/converts/const.ts
+++ b/src/parser/converts/const.ts
@@ -1,8 +1,8 @@
-import type { SvelteConstTag } from "../../ast";
-import type { Context } from "../../context";
-import { getDeclaratorFromConstTag } from "../compat";
-import type * as SvAST from "../svelte-ast-types";
-import type * as Compiler from "../svelte-ast-types-for-v5";
+import type { SvelteConstTag } from "../../ast/index.js";
+import type { Context } from "../../context/index.js";
+import { getDeclaratorFromConstTag } from "../compat.js";
+import type * as SvAST from "../svelte-ast-types.js";
+import type * as Compiler from "../svelte-ast-types-for-v5.js";
 
 /** Convert for ConstTag */
 export function convertConstTag(
diff --git a/src/parser/converts/element.ts b/src/parser/converts/element.ts
index b220e493..bbabaac6 100644
--- a/src/parser/converts/element.ts
+++ b/src/parser/converts/element.ts
@@ -26,11 +26,11 @@ import type {
   SvelteSpecialElement,
   SvelteStyleElement,
   SvelteText,
-} from "../../ast";
+} from "../../ast/index.js";
 import type ESTree from "estree";
-import type { Context } from "../../context";
-import type * as SvAST from "../svelte-ast-types";
-import type * as Compiler from "../svelte-ast-types-for-v5";
+import type { Context } from "../../context/index.js";
+import type * as SvAST from "../svelte-ast-types.js";
+import type * as Compiler from "../svelte-ast-types-for-v5.js";
 
 import {
   convertAwaitBlock,
@@ -38,22 +38,22 @@ import {
   convertIfBlock,
   convertKeyBlock,
   convertSnippetBlock,
-} from "./block";
-import { getWithLoc, indexOf } from "./common";
+} from "./block.js";
+import { getWithLoc, indexOf } from "./common.js";
 import {
   convertMustacheTag,
   convertDebugTag,
   convertRawMustacheTag,
-} from "./mustache";
-import { convertText } from "./text";
-import { convertAttributes } from "./attr";
-import { convertConstTag } from "./const";
-import { sortNodes } from "../sort";
-import type { ScriptLetBlockParam } from "../../context/script-let";
-import { ParseError } from "../..";
-import { convertRenderTag } from "./render";
-import type { Child } from "../compat";
-import { getChildren, getFragment } from "../compat";
+} from "./mustache.js";
+import { convertText } from "./text.js";
+import { convertAttributes } from "./attr.js";
+import { convertConstTag } from "./const.js";
+import { sortNodes } from "../sort.js";
+import type { ScriptLetBlockParam } from "../../context/script-let.js";
+import { ParseError } from "../../index.js";
+import { convertRenderTag } from "./render.js";
+import type { Child } from "../compat.js";
+import { getChildren, getFragment } from "../compat.js";
 
 /** Convert for Fragment or Element or ... */
 export function* convertChildren(
diff --git a/src/parser/converts/index.ts b/src/parser/converts/index.ts
index a6874cea..748fae2a 100644
--- a/src/parser/converts/index.ts
+++ b/src/parser/converts/index.ts
@@ -1 +1 @@
-export { convertSvelteRoot } from "./root";
+export { convertSvelteRoot } from "./root.js";
diff --git a/src/parser/converts/mustache.ts b/src/parser/converts/mustache.ts
index 60d74f94..6c8841b2 100644
--- a/src/parser/converts/mustache.ts
+++ b/src/parser/converts/mustache.ts
@@ -3,11 +3,11 @@ import type {
   SvelteMustacheTag,
   SvelteMustacheTagRaw,
   SvelteMustacheTagText,
-} from "../../ast";
-import type { Context } from "../../context";
-import type * as SvAST from "../svelte-ast-types";
-import { hasTypeInfo } from "../../utils";
-import type * as Compiler from "../svelte-ast-types-for-v5";
+} from "../../ast/index.js";
+import type { Context } from "../../context/index.js";
+import type * as SvAST from "../svelte-ast-types.js";
+import { hasTypeInfo } from "../../utils/index.js";
+import type * as Compiler from "../svelte-ast-types-for-v5.js";
 
 /** Convert for MustacheTag */
 export function convertMustacheTag(
diff --git a/src/parser/converts/render.ts b/src/parser/converts/render.ts
index ebe92805..796701a9 100644
--- a/src/parser/converts/render.ts
+++ b/src/parser/converts/render.ts
@@ -1,8 +1,8 @@
 import type * as ESTree from "estree";
-import type { SvelteRenderTag } from "../../ast";
-import type { Context } from "../../context";
-import { getWithLoc } from "./common";
-import type * as Compiler from "../svelte-ast-types-for-v5";
+import type { SvelteRenderTag } from "../../ast/index.js";
+import type { Context } from "../../context/index.js";
+import { getWithLoc } from "./common.js";
+import type * as Compiler from "../svelte-ast-types-for-v5.js";
 
 /** Convert for RenderTag */
 export function convertRenderTag(
diff --git a/src/parser/converts/root.ts b/src/parser/converts/root.ts
index 8253715a..5e5e8de3 100644
--- a/src/parser/converts/root.ts
+++ b/src/parser/converts/root.ts
@@ -1,5 +1,5 @@
-import type * as SvAST from "../svelte-ast-types";
-import type * as Compiler from "../svelte-ast-types-for-v5";
+import type * as SvAST from "../svelte-ast-types.js";
+import type * as Compiler from "../svelte-ast-types-for-v5.js";
 import type {
   SvelteAttribute,
   SvelteGenericsDirective,
@@ -8,25 +8,25 @@ import type {
   SvelteProgram,
   SvelteScriptElement,
   SvelteStyleElement,
-} from "../../ast";
-import {} from "./common";
-import type { Context } from "../../context";
-import { convertChildren, extractElementTags } from "./element";
-import { convertAttributes } from "./attr";
+} from "../../ast/index.js";
+import {} from "./common.js";
+import type { Context } from "../../context/index.js";
+import { convertChildren, extractElementTags } from "./element.js";
+import { convertAttributes } from "./attr.js";
 import type { Scope } from "eslint-scope";
-import { parseScriptWithoutAnalyzeScope } from "../script";
-import type { TSESParseForESLintResult } from "../typescript/types";
+import { parseScriptWithoutAnalyzeScope } from "../script.js";
+import type { TSESParseForESLintResult } from "../typescript/types.js";
 import type * as ESTree from "estree";
 import type { TSESTree } from "@typescript-eslint/types";
-import { fixLocations } from "../../context/fix-locations";
+import { fixLocations } from "../../context/fix-locations.js";
 import {
   getChildren,
   getFragmentFromRoot,
   getInstanceFromRoot,
   getModuleFromRoot,
   getOptionsFromRoot,
-} from "../compat";
-import { sortNodes } from "../sort";
+} from "../compat.js";
+import { sortNodes } from "../sort.js";
 
 /**
  * Convert root
diff --git a/src/parser/converts/text.ts b/src/parser/converts/text.ts
index 21289a1c..87acbaea 100644
--- a/src/parser/converts/text.ts
+++ b/src/parser/converts/text.ts
@@ -1,6 +1,6 @@
-import type { SvelteLiteral, SvelteText } from "../../ast";
-import type { Context } from "../../context";
-import type * as SvAST from "../svelte-ast-types";
+import type { SvelteLiteral, SvelteText } from "../../ast/index.js";
+import type { Context } from "../../context/index.js";
+import type * as SvAST from "../svelte-ast-types.js";
 /** Convert for Text */
 export function convertText(
   node: SvAST.Text,
diff --git a/src/parser/espree.ts b/src/parser/espree.ts
index ae8dc73e..df1b6e45 100644
--- a/src/parser/espree.ts
+++ b/src/parser/espree.ts
@@ -1,23 +1,6 @@
 import Module from "module";
 import path from "path";
-import type { BasicParserObject } from "./parser-object";
-
-const createRequire: (filename: string) => (modName: string) => any =
-  // Added in v12.2.0
-  Module.createRequire ||
-  // Added in v10.12.0, but deprecated in v12.2.0.
-  // @ts-expect-error -- old type
-  Module.createRequireFromPath ||
-  // Polyfill - This is not executed on the tests on node@>=10.
-  /* istanbul ignore next */
-  ((modName) => {
-    const mod = new Module(modName);
-
-    mod.filename = modName;
-    mod.paths = (Module as any)._nodeModulePaths(path.dirname(modName));
-    (mod as any)._compile("module.exports = require;", modName);
-    return mod.exports;
-  });
+import type { BasicParserObject } from "./parser-object.js";
 
 let espreeCache: (BasicParserObject & { latestEcmaVersion: number }) | null =
   null;
@@ -39,17 +22,26 @@ function isLinterPath(p: string): boolean {
 export function getEspree(): BasicParserObject & { latestEcmaVersion: number } {
   if (!espreeCache) {
     // Lookup the loaded eslint
-    const linterPath = Object.keys(require.cache || {}).find(isLinterPath);
+    const req = Module.createRequire(import.meta.url);
+    const linterPath = Object.keys(req.cache || {}).find(isLinterPath);
     if (linterPath) {
       try {
-        espreeCache = createRequire(linterPath)("espree");
+        espreeCache = Module.createRequire(linterPath)("espree");
+      } catch {
+        // ignore
+      }
+    }
+    if (!espreeCache) {
+      try {
+        return req("espree");
       } catch {
         // ignore
       }
     }
     if (!espreeCache) {
-      // eslint-disable-next-line @typescript-eslint/no-require-imports -- ignore
-      espreeCache = require("espree");
+      if (typeof require === "function")
+        // eslint-disable-next-line @typescript-eslint/no-require-imports -- ignore
+        espreeCache = require("espree");
     }
   }
 
diff --git a/src/parser/globals.ts b/src/parser/globals.ts
index 29ac3c9c..be66a663 100644
--- a/src/parser/globals.ts
+++ b/src/parser/globals.ts
@@ -1,4 +1,4 @@
-import type { SvelteParseContext } from "./svelte-parse-context";
+import type { SvelteParseContext } from "./svelte-parse-context.js";
 
 const globalsForSvelte = ["$$slots", "$$props", "$$restProps"] as const;
 export const globalsForRunes = [
diff --git a/src/parser/html.ts b/src/parser/html.ts
index a4b43072..6c713bc8 100644
--- a/src/parser/html.ts
+++ b/src/parser/html.ts
@@ -1,6 +1,6 @@
-import type * as Compiler from "./svelte-ast-types-for-v5";
+import type * as Compiler from "./svelte-ast-types-for-v5.js";
 import type ESTree from "estree";
-import { getEspree } from "./espree";
+import { getEspree } from "./espree.js";
 
 const RE_IS_SPACE = /^\s$/u;
 
diff --git a/src/parser/index.ts b/src/parser/index.ts
index 01e4d96c..f5722ae9 100644
--- a/src/parser/index.ts
+++ b/src/parser/index.ts
@@ -1,29 +1,32 @@
-import { KEYS } from "../visitor-keys";
-import { Context } from "../context";
+import { KEYS } from "../visitor-keys.js";
+import { Context } from "../context/index.js";
 import type {
   Comment,
   SvelteProgram,
   SvelteScriptElement,
   SvelteStyleElement,
   Token,
-} from "../ast";
+} from "../ast/index.js";
 import type { Program } from "estree";
 import type { ScopeManager } from "eslint-scope";
 import { Variable } from "eslint-scope";
-import { parseScript, parseScriptInSvelte } from "./script";
-import type * as SvAST from "./svelte-ast-types";
-import type * as Compiler from "./svelte-ast-types-for-v5";
-import { sortNodes } from "./sort";
-import { parseTemplate } from "./template";
+import { parseScript, parseScriptInSvelte } from "./script.js";
+import type * as SvAST from "./svelte-ast-types.js";
+import type * as Compiler from "./svelte-ast-types-for-v5.js";
+import { sortNodes } from "./sort.js";
+import { parseTemplate } from "./template.js";
 import {
   analyzePropsScope,
   analyzeReactiveScope,
   analyzeSnippetsScope,
   analyzeStoreScope,
-} from "./analyze-scope";
-import { ParseError } from "../errors";
-import { parseTypeScript, parseTypeScriptInSvelte } from "./typescript";
-import { addReference } from "../scope";
+} from "./analyze-scope.js";
+import { ParseError } from "../errors.js";
+import {
+  parseTypeScript,
+  parseTypeScriptInSvelte,
+} from "./typescript/index.js";
+import { addReference } from "../scope/index.js";
 import {
   parseStyleContext,
   type StyleContext,
@@ -33,19 +36,19 @@ import {
   type StyleContextUnknownLang,
   styleNodeLoc,
   styleNodeRange,
-} from "./style-context";
-import { getGlobalsForSvelte, getGlobalsForSvelteScript } from "./globals";
-import type { NormalizedParserOptions } from "./parser-options";
-import { isTypeScript, normalizeParserOptions } from "./parser-options";
-import { getFragmentFromRoot } from "./compat";
+} from "./style-context.js";
+import { getGlobalsForSvelte, getGlobalsForSvelteScript } from "./globals.js";
+import type { NormalizedParserOptions } from "./parser-options.js";
+import { isTypeScript, normalizeParserOptions } from "./parser-options.js";
+import { getFragmentFromRoot } from "./compat.js";
 import {
   isEnableRunes,
   resolveSvelteParseContextForSvelte,
   resolveSvelteParseContextForSvelteScript,
   type SvelteParseContext,
-} from "./svelte-parse-context";
-import type { SvelteConfig } from "../svelte-config";
-import { resolveSvelteConfigFromOption } from "../svelte-config";
+} from "./svelte-parse-context.js";
+import type { SvelteConfig } from "../svelte-config/index.js";
+import { resolveSvelteConfigFromOption } from "../svelte-config/index.js";
 
 export {
   StyleContext,
diff --git a/src/parser/parser-object.ts b/src/parser/parser-object.ts
index 995efc8f..5f85b732 100644
--- a/src/parser/parser-object.ts
+++ b/src/parser/parser-object.ts
@@ -1,4 +1,4 @@
-import type { ESLintExtendedProgram, ESLintProgram } from ".";
+import type { ESLintExtendedProgram, ESLintProgram } from "./index.js";
 import type * as tsESLintParser from "@typescript-eslint/parser";
 type TSESLintParser = typeof tsESLintParser;
 /**
diff --git a/src/parser/parser-options.ts b/src/parser/parser-options.ts
index c663406c..fd338485 100644
--- a/src/parser/parser-options.ts
+++ b/src/parser/parser-options.ts
@@ -3,8 +3,8 @@ import path from "path";
 import {
   isTSESLintParserObject,
   maybeTSESLintParserObject,
-} from "./parser-object";
-import { getParserForLang, type UserOptionParser } from "./resolve-parser";
+} from "./parser-object.js";
+import { getParserForLang, type UserOptionParser } from "./resolve-parser.js";
 
 export type NormalizedParserOptions = {
   parser?: UserOptionParser;
diff --git a/src/parser/resolve-parser.ts b/src/parser/resolve-parser.ts
index 9dab4de1..76553289 100644
--- a/src/parser/resolve-parser.ts
+++ b/src/parser/resolve-parser.ts
@@ -1,6 +1,7 @@
-import { getEspree } from "./espree";
-import type { ParserObject } from "./parser-object";
-import { isParserObject } from "./parser-object";
+import { getEspree } from "./espree.js";
+import type { ParserObject } from "./parser-object.js";
+import { isParserObject } from "./parser-object.js";
+import Module from "module";
 
 export type UserOptionParser =
   | string
@@ -37,7 +38,7 @@ export function getParser(
     return parserValue;
   }
   if (parserValue !== "espree") {
-    // eslint-disable-next-line @typescript-eslint/no-require-imports -- ignore
+    const require = Module.createRequire(import.meta.url);
     return require(parserValue);
   }
   return getEspree();
diff --git a/src/parser/script.ts b/src/parser/script.ts
index 80de7662..9055455d 100644
--- a/src/parser/script.ts
+++ b/src/parser/script.ts
@@ -1,9 +1,9 @@
-import type { ESLintExtendedProgram } from ".";
-import { analyzeScope } from "./analyze-scope";
-import { traverseNodes } from "../traverse";
-import { getParser } from "./resolve-parser";
-import { isEnhancedParserObject } from "./parser-object";
-import type { NormalizedParserOptions } from "./parser-options";
+import type { ESLintExtendedProgram } from "./index.js";
+import { analyzeScope } from "./analyze-scope.js";
+import { traverseNodes } from "../traverse.js";
+import { getParser } from "./resolve-parser.js";
+import { isEnhancedParserObject } from "./parser-object.js";
+import type { NormalizedParserOptions } from "./parser-options.js";
 
 /**
  * Parse for <script>
diff --git a/src/parser/style-context.ts b/src/parser/style-context.ts
index a162e403..249b9353 100644
--- a/src/parser/style-context.ts
+++ b/src/parser/style-context.ts
@@ -2,8 +2,8 @@ import type { Node, Parser, Root } from "postcss";
 import postcss from "postcss";
 import { parse as SCSSparse } from "postcss-scss";
 
-import type { Context } from "../context";
-import type { SourceLocation, SvelteStyleElement } from "../ast";
+import type { Context } from "../context/index.js";
+import type { SourceLocation, SvelteStyleElement } from "../ast/index.js";
 
 export type StyleContext =
   | StyleContextNoStyleElement
diff --git a/src/parser/svelte-parse-context.ts b/src/parser/svelte-parse-context.ts
index 18662040..d28799eb 100644
--- a/src/parser/svelte-parse-context.ts
+++ b/src/parser/svelte-parse-context.ts
@@ -1,8 +1,8 @@
-import type * as Compiler from "./svelte-ast-types-for-v5";
-import type * as SvAST from "./svelte-ast-types";
-import type { NormalizedParserOptions } from "./parser-options";
-import { compilerVersion, svelteVersion } from "./svelte-version";
-import type { SvelteConfig } from "../svelte-config";
+import type * as Compiler from "./svelte-ast-types-for-v5.js";
+import type * as SvAST from "./svelte-ast-types.js";
+import type { NormalizedParserOptions } from "./parser-options.js";
+import { compilerVersion, svelteVersion } from "./svelte-version.js";
+import type { SvelteConfig } from "../svelte-config/index.js";
 
 /** The context for parsing. */
 export type SvelteParseContext = {
diff --git a/src/parser/template.ts b/src/parser/template.ts
index 55133547..fffef84f 100644
--- a/src/parser/template.ts
+++ b/src/parser/template.ts
@@ -1,13 +1,13 @@
 import type {} from "svelte"; // FIXME: Workaround to get type information for "svelte/compiler"
 import { parse } from "svelte/compiler";
-import type * as Compiler from "./svelte-ast-types-for-v5";
-import type * as SvAST from "./svelte-ast-types";
-import type { Context } from "../context";
-import { convertSvelteRoot } from "./converts/index";
-import type { SvelteProgram } from "../ast";
-import { ParseError } from "..";
-import type { NormalizedParserOptions } from "./parser-options";
-import { svelteVersion } from "./svelte-version";
+import type * as Compiler from "./svelte-ast-types-for-v5.js";
+import type * as SvAST from "./svelte-ast-types.js";
+import type { Context } from "../context/index.js";
+import { convertSvelteRoot } from "./converts/index.js";
+import type { SvelteProgram } from "../ast/index.js";
+import { ParseError } from "../errors.js";
+import type { NormalizedParserOptions } from "./parser-options.js";
+import { svelteVersion } from "./svelte-version.js";
 
 /**
  * Parse for template
diff --git a/src/parser/typescript/analyze/index.ts b/src/parser/typescript/analyze/index.ts
index 6530e396..19d7ab7f 100644
--- a/src/parser/typescript/analyze/index.ts
+++ b/src/parser/typescript/analyze/index.ts
@@ -9,17 +9,20 @@ import {
   removeIdentifierReference,
   removeIdentifierVariable,
   replaceScope,
-} from "../../../scope";
-import { addElementsToSortedArray, sortedLastIndex } from "../../../utils";
-import { parseScriptWithoutAnalyzeScope } from "../../script";
-import { VirtualTypeScriptContext } from "../context";
-import type { TSESParseForESLintResult } from "../types";
+} from "../../../scope/index.js";
+import {
+  addElementsToSortedArray,
+  sortedLastIndex,
+} from "../../../utils/index.js";
+import { parseScriptWithoutAnalyzeScope } from "../../script.js";
+import { VirtualTypeScriptContext } from "../context.js";
+import type { TSESParseForESLintResult } from "../types.js";
 import type ESTree from "estree";
-import type { SvelteAttribute, SvelteHTMLElement } from "../../../ast";
-import type { NormalizedParserOptions } from "../../parser-options";
-import { setParent } from "../set-parent";
-import { getGlobalsForSvelte, globalsForRunes } from "../../globals";
-import type { SvelteParseContext } from "../../svelte-parse-context";
+import type { SvelteAttribute, SvelteHTMLElement } from "../../../ast/index.js";
+import type { NormalizedParserOptions } from "../../parser-options.js";
+import { setParent } from "../set-parent.js";
+import { getGlobalsForSvelte, globalsForRunes } from "../../globals.js";
+import type { SvelteParseContext } from "../../svelte-parse-context.js";
 
 export type AnalyzeTypeScriptContext = {
   slots: Set<SvelteHTMLElement>;
@@ -766,10 +769,10 @@ function transformForDeclareReactiveVar(
   ctx.appendVirtualScript(`}`);
 
   ctx.restoreContext.addRestoreStatementProcess((node, result) => {
-    if ((node as any).type !== "SvelteReactiveStatement") {
+    if (node.type !== "SvelteReactiveStatement") {
       return false;
     }
-    const reactiveStatement = node as TSESTree.LabeledStatement;
+    const reactiveStatement = node as never as TSESTree.LabeledStatement;
     if (
       reactiveStatement.body.type !== "VariableDeclaration" ||
       reactiveStatement.body.kind !== "let" ||
@@ -788,7 +791,7 @@ function transformForDeclareReactiveVar(
       return false;
     }
     const program = result.ast;
-    const nextIndex = program.body.indexOf(node) + 1;
+    const nextIndex = program.body.indexOf(reactiveStatement) + 1;
     const fnDecl = program.body[nextIndex];
     if (
       !fnDecl ||
@@ -900,10 +903,10 @@ function transformForReactiveStatement(
   ctx.appendOriginal(statement.range[1]);
 
   ctx.restoreContext.addRestoreStatementProcess((node, result) => {
-    if ((node as any).type !== "SvelteReactiveStatement") {
+    if (node.type !== "SvelteReactiveStatement") {
       return false;
     }
-    const reactiveStatement = node as TSESTree.LabeledStatement;
+    const reactiveStatement = node as never as TSESTree.LabeledStatement;
     const body = reactiveStatement.body;
     if (
       body.type !== "ExportNamedDeclaration" ||
diff --git a/src/parser/typescript/context.ts b/src/parser/typescript/context.ts
index 6e55c11e..856f370d 100644
--- a/src/parser/typescript/context.ts
+++ b/src/parser/typescript/context.ts
@@ -1,6 +1,6 @@
-import { UniqueIdGenerator } from "../../context/unique";
-import { RestoreContext } from "./restore";
-import type { TSESParseForESLintResult } from "./types";
+import { UniqueIdGenerator } from "../../context/unique.js";
+import { RestoreContext } from "./restore.js";
+import type { TSESParseForESLintResult } from "./types.js";
 
 /**
  * Context for virtual TypeScript code.
diff --git a/src/parser/typescript/index.ts b/src/parser/typescript/index.ts
index 91abd973..6a301e49 100644
--- a/src/parser/typescript/index.ts
+++ b/src/parser/typescript/index.ts
@@ -1,11 +1,14 @@
-import type { ESLintExtendedProgram } from "..";
-import type { NormalizedParserOptions } from "../parser-options";
-import { parseScript, parseScriptInSvelte } from "../script";
-import type { SvelteParseContext } from "../svelte-parse-context";
-import type { AnalyzeTypeScriptContext } from "./analyze";
-import { analyzeTypeScript, analyzeTypeScriptInSvelte } from "./analyze";
-import { setParent } from "./set-parent";
-import type { TSESParseForESLintResult } from "./types";
+import type { ESLintExtendedProgram } from "../index.js";
+import type { NormalizedParserOptions } from "../parser-options.js";
+import { parseScript, parseScriptInSvelte } from "../script.js";
+import type { SvelteParseContext } from "../svelte-parse-context.js";
+import type { AnalyzeTypeScriptContext } from "./analyze/index.js";
+import {
+  analyzeTypeScript,
+  analyzeTypeScriptInSvelte,
+} from "./analyze/index.js";
+import { setParent } from "./set-parent.js";
+import type { TSESParseForESLintResult } from "./types.js";
 
 /**
  * Parse for TypeScript in <script>
diff --git a/src/parser/typescript/restore.ts b/src/parser/typescript/restore.ts
index fd21cd89..557aafbb 100644
--- a/src/parser/typescript/restore.ts
+++ b/src/parser/typescript/restore.ts
@@ -1,7 +1,8 @@
 import type { TSESTree } from "@typescript-eslint/types";
-import { traverseNodes } from "../../traverse";
-import { LinesAndColumns } from "../../context";
-import type { TSESParseForESLintResult } from "./types";
+import { traverseNodes } from "../../traverse.js";
+import { LinesAndColumns } from "../../context/index.js";
+import type { TSESParseForESLintResult } from "./types.js";
+import type { SvelteReactiveStatement } from "../../ast/script.js";
 
 /**
  * A function that restores the statement.
@@ -14,7 +15,7 @@ import type { TSESParseForESLintResult } from "./types";
  *   This process will no longer be called.
  */
 type RestoreStatementProcess = (
-  node: TSESTree.Statement,
+  node: TSESTree.Statement | SvelteReactiveStatement,
   result: TSESParseForESLintResult,
 ) => boolean;
 /**
diff --git a/src/parser/typescript/set-parent.ts b/src/parser/typescript/set-parent.ts
index 01eb102a..1a6e4026 100644
--- a/src/parser/typescript/set-parent.ts
+++ b/src/parser/typescript/set-parent.ts
@@ -1,6 +1,6 @@
-import type { ESLintExtendedProgram } from "..";
-import { traverseNodes } from "../..";
-import type { TSESParseForESLintResult } from "./types";
+import type { ESLintExtendedProgram } from "../index.js";
+import { traverseNodes } from "../../index.js";
+import type { TSESParseForESLintResult } from "./types.js";
 
 export function setParent(
   result: ESLintExtendedProgram | TSESParseForESLintResult,
diff --git a/src/scope/index.ts b/src/scope/index.ts
index a3c3cb13..831fc8c2 100644
--- a/src/scope/index.ts
+++ b/src/scope/index.ts
@@ -1,8 +1,11 @@
 import type { ScopeManager, Scope, Reference, Variable } from "eslint-scope";
 import type * as ESTree from "estree";
 import type { TSESTree } from "@typescript-eslint/types";
-import { traverseNodes } from "../traverse";
-import { addElementsToSortedArray, addElementToSortedArray } from "../utils";
+import { traverseNodes } from "../traverse.js";
+import {
+  addElementsToSortedArray,
+  addElementToSortedArray,
+} from "../utils/index.js";
 
 /** Remove all scope, variable, and reference */
 export function removeAllScopeAndVariableAndReference(
diff --git a/src/svelte-config/index.ts b/src/svelte-config/index.ts
index 34ce79f5..aa60984e 100644
--- a/src/svelte-config/index.ts
+++ b/src/svelte-config/index.ts
@@ -1,6 +1,6 @@
 import path from "path";
 import fs from "fs";
-import { parseConfig } from "./parser";
+import { parseConfig } from "./parser.js";
 import type * as Compiler from "svelte/compiler";
 
 export type SvelteConfig = {
diff --git a/src/svelte-config/parser.ts b/src/svelte-config/parser.ts
index f4adc5e1..b9f44ba1 100644
--- a/src/svelte-config/parser.ts
+++ b/src/svelte-config/parser.ts
@@ -1,11 +1,11 @@
-import type { SvelteConfig } from ".";
+import type { SvelteConfig } from "./index.js";
 import type * as ESTree from "estree";
 import type { Scope } from "eslint";
 import type { ScopeManager } from "eslint-scope";
-import { getFallbackKeys, traverseNodes } from "../traverse";
-import { getEspree } from "../parser/espree";
+import { getFallbackKeys, traverseNodes } from "../traverse.js";
+import { getEspree } from "../parser/espree.js";
 import { analyze } from "eslint-scope";
-import { findVariable } from "../scope";
+import { findVariable } from "../scope/index.js";
 
 export function parseConfig(code: string): SvelteConfig | null {
   const espree = getEspree();
diff --git a/src/traverse.ts b/src/traverse.ts
index c801694b..e4173f36 100644
--- a/src/traverse.ts
+++ b/src/traverse.ts
@@ -1,7 +1,7 @@
 import type { VisitorKeys } from "eslint-visitor-keys";
-import { KEYS } from "./visitor-keys";
+import { KEYS } from "./visitor-keys.js";
 import type ESTree from "estree";
-import type { SvelteNode } from "./ast";
+import type { SvelteNode } from "./ast/index.js";
 import type { TSESTree } from "@typescript-eslint/types";
 import type { VisitorKeys as TSESVisitorKeys } from "@typescript-eslint/visitor-keys";
 
diff --git a/src/visitor-keys.ts b/src/visitor-keys.ts
index 56e76324..3a7492c6 100644
--- a/src/visitor-keys.ts
+++ b/src/visitor-keys.ts
@@ -1,6 +1,6 @@
 import type { SourceCode } from "eslint";
 import { unionWith } from "eslint-visitor-keys";
-import type { SvelteNode } from "./ast";
+import type { SvelteNode } from "./ast/index.js";
 
 type SvelteKeysType<T extends SvelteNode = SvelteNode> = {
   [key in SvelteNode["type"]]: T extends { type: key }
diff --git a/tests/src/integrations.ts b/tests/src/integrations.ts
index 9abbbafb..04334fbb 100644
--- a/tests/src/integrations.ts
+++ b/tests/src/integrations.ts
@@ -1,17 +1,17 @@
-/* global require -- node */
 import { Linter } from "eslint";
 import assert from "assert";
 import fs from "fs";
 import globals from "globals";
-import * as parser from "../../src";
+import * as parser from "../../src/index.js";
 import {
   generateParserOptions,
   getMessageData,
   listupFixtures,
-} from "./parser/test-utils";
+} from "./parser/test-utils.js";
 import path from "path";
 
-const FIXTURE_ROOT = path.resolve(__dirname, "../fixtures/integrations");
+const dirname = path.dirname(new URL(import.meta.url).pathname);
+const FIXTURE_ROOT = path.resolve(dirname, "../fixtures/integrations");
 
 describe("Integration tests.", () => {
   for (const {
@@ -24,14 +24,13 @@ describe("Integration tests.", () => {
     if (!meetRequirements("parse")) {
       continue;
     }
-    it(inputFileName, () => {
+    it(inputFileName, async () => {
       const setupFileName = inputFileName.replace(
         /input\.svelte(?:\.[jt]s)?$/u,
         "setup.ts",
       );
       const setup = fs.existsSync(setupFileName)
-        ? // eslint-disable-next-line @typescript-eslint/no-require-imports -- test
-          require(setupFileName)
+        ? await import(setupFileName)
         : null;
       const linter = new Linter();
       const messages = linter.verify(
diff --git a/tests/src/meta.ts b/tests/src/meta.ts
index 72e0622b..28d849ea 100644
--- a/tests/src/meta.ts
+++ b/tests/src/meta.ts
@@ -1,6 +1,7 @@
 import assert from "assert";
-import * as parser from "../../src";
-import { version } from "../../package.json";
+import * as parser from "../../src/index.js";
+import pkg from "../../package.json" with { type: "json" };
+const { version } = pkg;
 const expectedMeta = {
   name: "svelte-eslint-parser",
   version,
@@ -8,6 +9,6 @@ const expectedMeta = {
 
 describe("Test for meta object", () => {
   it("A parser should have a meta object.", () => {
-    assert.deepStrictEqual(parser.meta, expectedMeta);
+    assert.deepStrictEqual({ ...parser.meta }, expectedMeta);
   });
 });
diff --git a/tests/src/parser/error.ts b/tests/src/parser/error.ts
index 242b13ef..c0977b92 100644
--- a/tests/src/parser/error.ts
+++ b/tests/src/parser/error.ts
@@ -1,18 +1,16 @@
 import assert from "assert";
 import fs from "fs";
-import { parseForESLint } from "../../../src";
+import { parseForESLint } from "../../../src/index.js";
 import {
   generateParserOptions,
   listupFixtures,
   astToJson,
   normalizeError,
-} from "./test-utils";
+} from "./test-utils.js";
 import path from "path";
 
-const ERROR_FIXTURE_ROOT = path.resolve(
-  __dirname,
-  "../../fixtures/parser/error",
-);
+const dirname = path.dirname(new URL(import.meta.url).pathname);
+const ERROR_FIXTURE_ROOT = path.resolve(dirname, "../../fixtures/parser/error");
 
 function parse(code: string, filePath: string, config: any) {
   return parseForESLint(code, generateParserOptions({ filePath }, config));
diff --git a/tests/src/parser/eslint.ts b/tests/src/parser/eslint.ts
index 59a926c7..79558a69 100644
--- a/tests/src/parser/eslint.ts
+++ b/tests/src/parser/eslint.ts
@@ -2,9 +2,11 @@ import { Linter } from "eslint";
 import assert from "assert";
 import semver from "semver";
 import globals from "globals";
-import * as parser from "../../../src/index";
-import { generateParserOptions } from "./test-utils";
+import * as parser from "../../../src/index.js";
+import { generateParserOptions } from "./test-utils.js";
+import { Module } from "module";
 
+const require = Module.createRequire(import.meta.url);
 //------------------------------------------------------------------------------
 // Tests
 //------------------------------------------------------------------------------
@@ -220,11 +222,7 @@ describe("eslint custom parser", () => {
         output: null,
         messages: [],
       },
-      ...(semver.satisfies(
-        // eslint-disable-next-line @typescript-eslint/no-require-imports, @typescript-eslint/no-var-requires -- ignore
-        require("eslint/package.json").version,
-        ">=8.0.0",
-      )
+      ...(semver.satisfies(require("eslint/package.json").version, ">=8.0.0")
         ? [
             {
               // test for ecmaVersion latest
diff --git a/tests/src/parser/parser.ts b/tests/src/parser/parser.ts
index 32cf5e1b..f6bb78f8 100644
--- a/tests/src/parser/parser.ts
+++ b/tests/src/parser/parser.ts
@@ -1,19 +1,21 @@
-/* global require -- node */
 import assert from "assert";
 import fs from "fs";
 import semver from "semver";
 
-import { traverseNodes } from "../../../src/traverse";
-import { parseForESLint } from "../../../src";
+import { traverseNodes } from "../../../src/traverse.js";
+import { parseForESLint } from "../../../src/index.js";
 import {
   generateParserOptions,
   listupFixtures,
   astToJson,
   scopeToJSON,
-} from "./test-utils";
-import type { Comment, SvelteProgram, Token } from "../../../src/ast";
-import { sortNodes } from "../../../src/parser/sort";
-import { sortJson } from "./test-utils";
+} from "./test-utils.js";
+import type { Comment, SvelteProgram, Token } from "../../../src/ast/index.js";
+import { sortNodes } from "../../../src/parser/sort.js";
+import { sortJson } from "./test-utils.js";
+import Module from "module";
+
+const require = Module.createRequire(import.meta.url);
 
 function parse(code: string, filePath: string, config: any) {
   return parseForESLint(code, generateParserOptions({ filePath }, config));
@@ -52,7 +54,6 @@ describe("Check for AST.", () => {
           if (
             result.services?.program // use ts parser
           ) {
-            // eslint-disable-next-line @typescript-eslint/no-require-imports, @typescript-eslint/no-var-requires -- ignore
             const pkg = require("@typescript-eslint/parser/package.json");
             if (!semver.satisfies(pkg.version, "^5.6.0")) {
               // adjust global scope
diff --git a/tests/src/parser/style-context.ts b/tests/src/parser/style-context.ts
index 109e71e8..819456c5 100644
--- a/tests/src/parser/style-context.ts
+++ b/tests/src/parser/style-context.ts
@@ -2,15 +2,16 @@ import assert from "assert";
 import fs from "fs";
 import path from "path";
 
-import { parseForESLint } from "../../../src";
+import { parseForESLint } from "../../../src/index.js";
 import {
   generateParserOptions,
   listupFixtures,
   styleContextToJson,
-} from "./test-utils";
+} from "./test-utils.js";
 
+const dirname = path.dirname(new URL(import.meta.url).pathname);
 const STYLE_CONTEXT_FIXTURE_ROOT = path.resolve(
-  __dirname,
+  dirname,
   "../../fixtures/parser/style-context",
 );
 
diff --git a/tests/src/parser/style-location-coverter.ts b/tests/src/parser/style-location-coverter.ts
index 95482868..cbe96d2a 100644
--- a/tests/src/parser/style-location-coverter.ts
+++ b/tests/src/parser/style-location-coverter.ts
@@ -3,12 +3,13 @@ import fs from "fs";
 import path from "path";
 import type { Node } from "postcss";
 
-import { parseForESLint } from "../../../src";
-import type { SourceLocation } from "../../../src/ast";
-import { generateParserOptions, listupFixtures } from "./test-utils";
+import { parseForESLint } from "../../../src/index.js";
+import { generateParserOptions, listupFixtures } from "./test-utils.js";
+import type { SourceLocation } from "../../../src/ast/common.js";
 
+const dirname = path.dirname(new URL(import.meta.url).pathname);
 const STYLE_CONTEXT_FIXTURE_ROOT = path.resolve(
-  __dirname,
+  dirname,
   "../../fixtures/parser/style-location-converter",
 );
 
diff --git a/tests/src/parser/test-utils.ts b/tests/src/parser/test-utils.ts
index 8d98c0e6..b269816f 100644
--- a/tests/src/parser/test-utils.ts
+++ b/tests/src/parser/test-utils.ts
@@ -1,18 +1,20 @@
-/* global require -- node */
 import path from "path";
 import fs from "fs";
 import semver from "semver";
 import type { Linter, Scope as ESLintScope } from "eslint";
-import { LinesAndColumns } from "../../../src/context";
+import { LinesAndColumns } from "../../../src/context/index.js";
 import type { Reference, Scope, ScopeManager, Variable } from "eslint-scope";
 import type * as TSESScopes from "@typescript-eslint/scope-manager";
-import type { SvelteNode } from "../../../src/ast";
-import type { StyleContext } from "../../../src";
-import { TS_GLOBALS } from "./ts-vars";
-import { svelteVersion } from "../../../src/parser/svelte-version";
-import type { NormalizedParserOptions } from "../../../src/parser/parser-options";
-
-const AST_FIXTURE_ROOT = path.resolve(__dirname, "../../fixtures/parser/ast");
+import type { SvelteNode } from "../../../src/ast/index.js";
+import type { StyleContext } from "../../../src/index.js";
+import { TS_GLOBALS } from "./ts-vars.js";
+import { svelteVersion } from "../../../src/parser/svelte-version.js";
+import type { NormalizedParserOptions } from "../../../src/parser/parser-options.js";
+import Module from "module";
+
+const require = Module.createRequire(import.meta.url);
+const dirname = path.dirname(new URL(import.meta.url).pathname);
+const AST_FIXTURE_ROOT = path.resolve(dirname, "../../fixtures/parser/ast");
 const BASIC_PARSER_OPTIONS: Linter.ParserOptions = {
   ecmaVersion: 2020,
   parser: {
@@ -94,13 +96,7 @@ export function generateParserOptions(
 export function generateParserOptions(
   ...options: (Linter.ParserOptions | NormalizedParserOptions)[]
 ): Linter.ParserOptions | NormalizedParserOptions {
-  let result: Linter.ParserOptions | NormalizedParserOptions = {
-    ...BASIC_PARSER_OPTIONS,
-  };
-  for (const option of options) {
-    result = { ...result, ...option };
-  }
-  return result;
+  return Object.assign({}, BASIC_PARSER_OPTIONS, ...options);
 }
 export function* listupFixtures(dir?: string): Iterable<{
   input: string;
@@ -303,7 +299,6 @@ function* listupFixturesImpl(dir: string): Iterable<{
           if (obj) {
             if (
               Object.entries(obj).some(([pkgName, pkgVersion]) => {
-                // eslint-disable-next-line @typescript-eslint/no-require-imports, @typescript-eslint/no-var-requires -- ignore
                 const pkg = require(`${pkgName}/package.json`);
                 return !semver.satisfies(pkg.version, pkgVersion as string);
               })
diff --git a/tests/src/parser/typescript/index.ts b/tests/src/parser/typescript/index.ts
index 49051278..50144dec 100644
--- a/tests/src/parser/typescript/index.ts
+++ b/tests/src/parser/typescript/index.ts
@@ -1,11 +1,11 @@
-import { Context } from "../../../../src/context";
-import type { NormalizedParserOptions } from "../../../../src/parser/parser-options";
-import { parseScriptInSvelte } from "../../../../src/parser/script";
-import { compilerVersion } from "../../../../src/parser/svelte-version";
-import { parseTemplate } from "../../../../src/parser/template";
-import { parseTypeScriptInSvelte } from "../../../../src/parser/typescript";
-import { generateParserOptions, listupFixtures } from "../test-utils";
-import { assertResult } from "./assert-result";
+import { Context } from "../../../../src/context/index.js";
+import type { NormalizedParserOptions } from "../../../../src/parser/parser-options.js";
+import { parseScriptInSvelte } from "../../../../src/parser/script.js";
+import { compilerVersion } from "../../../../src/parser/svelte-version.js";
+import { parseTemplate } from "../../../../src/parser/template.js";
+import { parseTypeScriptInSvelte } from "../../../../src/parser/typescript/index.js";
+import { generateParserOptions, listupFixtures } from "../test-utils.js";
+import { assertResult } from "./assert-result.js";
 
 describe("Check for typescript analyze result.", () => {
   for (const {
diff --git a/tests/src/svelte-config/parser.ts b/tests/src/svelte-config/parser.ts
index 2bc3a199..a205140e 100644
--- a/tests/src/svelte-config/parser.ts
+++ b/tests/src/svelte-config/parser.ts
@@ -1,5 +1,5 @@
 import assert from "assert";
-import { parseConfig } from "../../../src/svelte-config/parser";
+import { parseConfig } from "../../../src/svelte-config/parser.js";
 
 describe("parseConfig", () => {
   const testCases = [
diff --git a/tools/update-fixtures.ts b/tools/update-fixtures.ts
index fb00cad1..07532fff 100644
--- a/tools/update-fixtures.ts
+++ b/tools/update-fixtures.ts
@@ -1,8 +1,8 @@
 import fs from "fs";
 import path from "path";
 import { Linter } from "eslint";
-import * as parser from "../src/index";
-import { parseForESLint } from "../src/parser";
+import * as parser from "../src/index.js";
+import { parseForESLint } from "../src/parser/index.js";
 import {
   generateParserOptions,
   getMessageData,
@@ -11,23 +11,24 @@ import {
   normalizeError,
   scopeToJSON,
   styleContextToJson,
-} from "../tests/src/parser/test-utils";
+} from "../tests/src/parser/test-utils.js";
 import type ts from "typescript";
 import type ESTree from "estree";
 import globals from "globals";
-import type { SourceLocation } from "../src/ast";
+import type { SourceLocation } from "../src/ast/index.js";
 
+const dirname = path.dirname(new URL(import.meta.url).pathname);
 const ERROR_FIXTURE_ROOT = path.resolve(
-  __dirname,
+  dirname,
   "../tests/fixtures/parser/error",
 );
 
 const STYLE_CONTEXT_FIXTURE_ROOT = path.resolve(
-  __dirname,
+  dirname,
   "../tests/fixtures/parser/style-context",
 );
 const STYLE_LOCATION_FIXTURE_ROOT = path.resolve(
-  __dirname,
+  dirname,
   "../tests/fixtures/parser/style-location-converter",
 );
 
diff --git a/tools/update-meta.ts b/tools/update-meta.ts
index ad11a74e..3681f767 100644
--- a/tools/update-meta.ts
+++ b/tools/update-meta.ts
@@ -1,10 +1,12 @@
 import fs from "fs";
 import path from "path";
 import { ESLint } from "eslint";
-import { name, version } from "../package.json";
-import { getNewVersion } from "./lib/changesets-util";
+import pkg from "../package.json" with { type: "json" };
+import { getNewVersion } from "./lib/changesets-util.js";
+const { name, version } = pkg;
 
-const META_PATH = path.join(__dirname, "../src/meta.ts");
+const dirname = path.dirname(new URL(import.meta.url).pathname);
+const META_PATH = path.join(dirname, "../src/meta.ts");
 
 void main();
 
diff --git a/tsconfig.json b/tsconfig.json
index 1f44a58a..b269aca0 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,10 +1,12 @@
 {
   "compilerOptions": {
-    "target": "es2015",
+    "target": "es2020",
     "strict": true,
     "lib": ["es2020", "DOM"],
     "module": "NodeNext",
     "moduleResolution": "Node16",
+    "allowJs": true,
+    "checkJs": true,
     "declaration": true,
     "noImplicitAny": true,
     "noImplicitReturns": true,