switch to esm, requires node 12+

.eslintrc.json

@@ -1,5 +1,5 @@
 {
-  "extends": "xo/esnext",
+  "extends": "xo",
   "rules": {
     "semi": [
       "error",

.github/workflows/node.js.yml

@@ -16,7 +16,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [10.x, 12.x, 14.x]
+        node-version: [12.x, 14.x, 16.x]
 
     steps:
     - uses: actions/checkout@v2

cli.js

@@ -1,6 +1,6 @@
 #!/usr/bin/env node
 
-const diff = require('./lib/diff')
+import diff from './lib/diff.js'
 
 const output = ({error, result}) => {
   if (error) {

cli.test.js

@@ -1,5 +1,5 @@
-const {spawn} = require('child_process')
-const test = require('tape')
+import {spawn} from 'node:child_process'
+import test from 'tape'
 
 const run = async args => {
   const stderr = []

lib/diff.js

@@ -1,4 +1,4 @@
-const list = require('./list')
+import list from './list.js'
 
 const diff = async ({source, target}) => {
   const left = await list(source)
@@ -11,4 +11,4 @@ const diff = async ({source, target}) => {
     .map(file => file.name)
 }
 
-module.exports = diff
+export default diff

lib/diff.test.js

@@ -1,5 +1,5 @@
-const test = require('tape')
-const diff = require('./diff')
+import test from 'tape'
+import diff from './diff.js'
 
 test('diff files, when using same tree', async assert => {
   const message = 'diff result must be empty'

lib/list.js

@@ -1,5 +1,5 @@
-const path = require('path')
-const fs = require('fs').promises
+import path from 'node:path'
+import fs from 'node:fs/promises'
 
 const list = async pathdir => {
   try {
@@ -27,4 +27,4 @@ const list = async pathdir => {
   }
 }
 
-module.exports = list
+export default list

lib/list.test.js

@@ -1,5 +1,5 @@
-const test = require('tape')
-const list = require('./list')
+import test from 'tape'
+import list from './list.js'
 
 test('list files, when using flat tree', async assert => {
   const message = 'should list 10 files'