Initial ESM porting effort

.github/workflows/node.js.yml

@@ -16,7 +16,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [16.x, 18.x, 20.x]
+        node-version: [18.x, 20.x]
         # See supported Node.js release schedule at https://nodejs.org/en/about/releases/
 
     steps:
@@ -27,4 +27,4 @@ jobs:
           node-version: ${{ matrix.node-version }}
           cache: 'npm'
       - run: npm install
-      - run: npm test
+      - run: npm test:coverage

eslint.config.js

@@ -13,7 +13,7 @@ const compat = new FlatCompat({
 });
 
 export default [{
-    ignores: ["**/*tmp*/", "**/*tmp*.*"],
+    ignores: ["**/*tmp*/", "**/*tmp*.*", "eslint.config.js", "node_modules/"],
 }, ...compat.extends("eslint:recommended"), {
     languageOptions: {
         globals: {
@@ -23,7 +23,7 @@ export default [{
         },
 
         ecmaVersion: "latest",
-        sourceType: "commonjs",
+        sourceType: "module",
     },
 
     rules: {

package.json

@@ -7,7 +7,8 @@
   "scripts": {
     "lint": "eslint .",
     "prepare": "husky",
-    "test": "node tests/tester.js"
+    "test": "node --test",
+    "test:coverage": "node --test --experimental-test-coverage"
   },
   "repository": {
     "type": "git",

src/arborist.js

@@ -1,4 +1,4 @@
-const {generateCode, generateFlatAST,} = require('./flast');
+import {generateCode, generateFlatAST} from './flast.js';
 
 const Arborist = class {
 	/**
@@ -169,6 +169,6 @@ const Arborist = class {
 	}
 };
 
-module.exports = {
+export {
 	Arborist,
 };

src/flast.js

@@ -1,7 +1,7 @@
-const {parse} = require('espree');
-const {generate, attachComments} = require('escodegen');
-const estraverse = require('estraverse');
-const {analyze} = require('eslint-scope');
+import {parse} from 'espree';
+import {generate, attachComments} from 'escodegen';
+import estraverse from 'estraverse';
+import {analyze} from 'eslint-scope';
 
 const ecmaVersion = 'latest';
 const sourceType = 'module';
@@ -288,7 +288,7 @@ async function generateFlatASTAsync(inputCode, opts = {}) {
 	return Promise.all(promises).then(() => tree);
 }
 
-module.exports = {
+export {
 	estraverse,
 	extractNodesFromRoot,
 	generateCode,

src/index.js

@@ -1,6 +1,4 @@
-module.exports = {
-	...require('./flast'),
-	...require('./arborist'),
-	...require('./types'),
-	utils: require('./utils'),
-};
+export * from './flast.js';
+export * from './arborist.js';
+export * from './types.js';
+export * from './utils/index.js';

src/types.js

@@ -1,4 +1,4 @@
-const {Scope} = require('eslint-scope');
+import {Scope} from 'eslint-scope';
 
 /**
  * @typedef ASTNode
@@ -88,7 +88,7 @@ class ASTNode {}
  */
 class ASTScope extends Scope {}
 
-module.exports = {
+export {
 	ASTNode,
 	ASTScope,
 };

src/utils/applyIteratively.js

@@ -1,6 +1,6 @@
-const {Arborist} = require('../arborist');
-const logger = require('./logger');
-const {createHash} = require('node:crypto');
+import {Arborist} from '../arborist.js';
+import {logger} from './logger.js';
+import {createHash} from 'node:crypto';
 
 const generateHash = str => createHash('sha256').update(str).digest('hex');
 
@@ -12,7 +12,7 @@ const generateHash = str => createHash('sha256').update(str).digest('hex');
  * @param {number?} maxIterations (optional) Stop the loop after this many iterations at most.
  * @return {string} The possibly modified script.
  */
-function runLoop(script, funcs, maxIterations = 500) {
+function applyIteratively(script, funcs, maxIterations = 500) {
 	let scriptSnapshot = '';
 	let currentIteration = 0;
 	let changesCounter = 0;
@@ -62,4 +62,4 @@ function runLoop(script, funcs, maxIterations = 500) {
 	return script;
 }
 
-module.exports = runLoop;
+export {applyIteratively};

src/utils/index.js

@@ -1,5 +1,5 @@
-module.exports = {
-	applyIteratively: require('./applyIteratively'),
-	logger: require('./logger'),
-	treeModifier: require('./treeModifier'),
+export const utils = {
+	applyIteratively: (await import('./applyIteratively.js')).applyIteratively,
+	logger: (await import('./logger.js')).logger,
+	treeModifier: (await import('./treeModifier.js')).treeModifier,
 };

src/utils/logger.js

@@ -35,10 +35,10 @@ const logger = {
 	setLogLevelDebug() {this.setLogLevel(this.logLevels.DEBUG);},
 	setLogLevelLog() {this.setLogLevel(this.logLevels.LOG);},
 	setLogLevelError() {this.setLogLevel(this.logLevels.ERROR);},
-  
+
 	setLogFunc(newLogfunc) {
 		this.logFunc = newLogfunc;
 	},
 };
 
-module.exports = logger;
+export {logger};

src/utils/treeModifier.js

@@ -20,4 +20,4 @@ function treeModifier(filterFunc, modFunc, funcName) {
 	return func;
 }
 
-module.exports = treeModifier;
+export {treeModifier};