feat!: change the parser to an ESM-only package (#599)

Author: ota-meshi

.changeset/quick-beers-reflect.md

@@ -0,0 +1,5 @@
+---
+"svelte-eslint-parser": major
+---
+
+feat!: change the parser to an ESM-only package

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

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"),

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

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",
@@ -100,14 +100,14 @@
     "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",
     "rimraf": "^6.0.1",
     "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"

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 {

src/ast/common.ts

@@ -1,4 +1,4 @@
-import type { BaseNode } from "./base";
+import type { BaseNode } from "./base.js";
 
 export interface Position {
   /** >= 1 */

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

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;

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;
 

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(