feat!: change the parser to an ESM-only package

Author: ota-meshi

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"
@@ -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"
@@ -82,7 +82,6 @@
     "chai": "^4.5.0",
     "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",
@@ -108,6 +107,7 @@
     "semver": "^7.6.3",
     "svelte": "^5.2.11",
     "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(

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;