.editorconfig

@@ -7,6 +7,6 @@ charset = utf-8
 trim_trailing_whitespace = true
 insert_final_newline = true
 
-[{package.json,*.yml}]
+[*.yml]
 indent_style = space
 indent_size = 2

.gitattributes

@@ -1 +1 @@
-* text=auto
+* text=auto eol=lf

.github/funding.yml

@@ -0,0 +1,2 @@
+github: sindresorhus
+tidelift: npm/update-notifier

.github/security.md

@@ -0,0 +1,3 @@
+# Security Policy
+
+To report a security vulnerability, please use the [Tidelift security contact](https://tidelift.com/security). Tidelift will coordinate the fix and disclosure.

.github/workflows/main.yml

@@ -0,0 +1,22 @@
+name: CI
+on:
+  - push
+  - pull_request
+jobs:
+  test:
+    name: Node.js ${{ matrix.node-version }}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        node-version:
+          - 18
+          - 16
+          - 14
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-node@v3
+        with:
+          node-version: ${{ matrix.node-version }}
+      - run: npm install
+      - run: npm test

.gitignore

@@ -1 +1,2 @@
-node_modules
+node_modules
+yarn.lock

.npmrc

@@ -0,0 +1 @@
+package-lock=false

check.js

@@ -1,22 +1,26 @@
 /* eslint-disable unicorn/no-process-exit */
-'use strict';
-var updateNotifier = require('./');
+import process from 'node:process';
+import UpdateNotifier from './update-notifier.js';
 
-var options = JSON.parse(process.argv[2]);
+const updateNotifier = new UpdateNotifier(JSON.parse(process.argv[2]));
 
-updateNotifier = new updateNotifier.UpdateNotifier(options);
+try {
+	// Exit process when offline
+	setTimeout(process.exit, 1000 * 30);
 
-updateNotifier.checkNpm().then(function (update) {
-	// only update the last update check time on success
+	const update = await updateNotifier.fetchInfo();
+
+	// Only update the last update check time on success
 	updateNotifier.config.set('lastUpdateCheck', Date.now());
 
 	if (update.type && update.type !== 'latest') {
 		updateNotifier.config.set('update', update);
 	}
 
-	// Call process exit explicitly to terminate the child process
-	// Otherwise the child process will run forever (according to nodejs docs)
+	// Call process exit explicitly to terminate the child process,
+	// otherwise the child process will run forever, according to the Node.js docs
 	process.exit();
-}).catch(function () {
+} catch (error) {
+	console.error(error);
 	process.exit(1);
-});
+}

contributing.md

@@ -1 +1 @@
-See the [contributing docs](https://github.com/yeoman/yeoman/blob/master/contributing.md)
+See the [contributing docs](https://github.com/yeoman/yeoman/blob/main/contributing.md)

example.js

@@ -1,12 +1,16 @@
-'use strict';
-var updateNotifier = require('./');
+import updateNotifier from './index.js';
 
-// you have to run this file two times the first time
+// Run: $ node example
+
+// You have to run this file two times the first time
+// This is because it never reports updates on the first run
+// If you want to test your own usage, ensure you set an older version
 
 updateNotifier({
 	pkg: {
 		name: 'public-ip',
-		version: '0.9.2'
+		version: '0.9.2',
 	},
-	updateCheckInterval: 0
-}).notify();
+	updateCheckInterval: 0,
+})
+	.notify();

index.js

@@ -1,146 +1,7 @@
-'use strict';
-var spawn = require('child_process').spawn;
-var path = require('path');
-var format = require('util').format;
-var lazyRequire = require('lazy-req')(require);
+import UpdateNotifier from './update-notifier.js';
 
-var configstore = lazyRequire('configstore');
-var chalk = lazyRequire('chalk');
-var semverDiff = lazyRequire('semver-diff');
-var latestVersion = lazyRequire('latest-version');
-var isNpm = lazyRequire('is-npm');
-var boxen = lazyRequire('boxen');
-var xdgBasedir = lazyRequire('xdg-basedir');
-var ONE_DAY = 1000 * 60 * 60 * 24;
-
-function UpdateNotifier(options) {
-	this.options = options = options || {};
-	options.pkg = options.pkg || {};
-
-	// reduce pkg to the essential keys. with fallback to deprecated options
-	// TODO: remove deprecated options at some point far into the future
-	options.pkg = {
-		name: options.pkg.name || options.packageName,
-		version: options.pkg.version || options.packageVersion
-	};
-
-	if (!options.pkg.name || !options.pkg.version) {
-		throw new Error('pkg.name and pkg.version required');
-	}
-
-	this.packageName = options.pkg.name;
-	this.packageVersion = options.pkg.version;
-	this.updateCheckInterval = typeof options.updateCheckInterval === 'number' ? options.updateCheckInterval : ONE_DAY;
-	this.hasCallback = typeof options.callback === 'function';
-	this.callback = options.callback || function () {};
-
-	if (!this.hasCallback) {
-		try {
-			var ConfigStore = configstore();
-			this.config = new ConfigStore('update-notifier-' + this.packageName, {
-				optOut: false,
-				// init with the current time so the first check is only
-				// after the set interval, so not to bother users right away
-				lastUpdateCheck: Date.now()
-			});
-		} catch (err) {
-			// expecting error code EACCES or EPERM
-			var msg =
-				chalk().yellow(format(' %s update check failed ', options.pkg.name)) +
-				format('\n Try running with %s or get access ', chalk().cyan('sudo')) +
-				'\n to the local update config store via \n' +
-				chalk().cyan(format(' sudo chown -R $USER:$(id -gn $USER) %s ', xdgBasedir().config));
-
-			process.on('exit', function () {
-				console.error('\n' + boxen()(msg, {align: 'center'}));
-			});
-		}
-	}
-}
-
-UpdateNotifier.prototype.check = function () {
-	if (this.hasCallback) {
-		this.checkNpm().then(this.callback.bind(this, null)).catch(this.callback);
-		return;
-	}
-	if (
-		!this.config ||
-		this.config.get('optOut') ||
-		'NO_UPDATE_NOTIFIER' in process.env ||
-		process.argv.indexOf('--no-update-notifier') !== -1
-	) {
-		return;
-	}
-
-	this.update = this.config.get('update');
-
-	if (this.update) {
-		this.config.del('update');
-	}
-
-	// Only check for updates on a set interval
-	if (Date.now() - this.config.get('lastUpdateCheck') < this.updateCheckInterval) {
-		return;
-	}
-
-	// Spawn a detached process, passing the options as an environment property
-	spawn(process.execPath, [path.join(__dirname, 'check.js'), JSON.stringify(this.options)], {
-		detached: true,
-		stdio: 'ignore'
-	}).unref();
-};
-
-UpdateNotifier.prototype.checkNpm = function () {
-	return latestVersion()(this.packageName).then(function (latestVersion) {
-		return {
-			latest: latestVersion,
-			current: this.packageVersion,
-			type: semverDiff()(this.packageVersion, latestVersion) || 'latest',
-			name: this.packageName
-		};
-	}.bind(this));
-};
-
-UpdateNotifier.prototype.notify = function (opts) {
-	if (!process.stdout.isTTY || isNpm() || !this.update) {
-		return this;
-	}
-
-	opts = opts || {};
-
-	opts.message = opts.message || 'Update available ' + chalk().dim(this.update.current) + chalk().reset(' → ') +
-		chalk().green(this.update.latest) + ' \nRun ' + chalk().cyan('npm i -g ' + this.packageName) + ' to update';
-
-	opts.boxenOpts = opts.boxenOpts || {
-		padding: 1,
-		margin: 1,
-		align: 'center',
-		borderColor: 'yellow',
-		borderStyle: 'round'
-	};
-
-	var message = '\n' + boxen()(opts.message, opts.boxenOpts);
-
-	if (opts.defer === false) {
-		console.error(message);
-	} else {
-		process.on('exit', function () {
-			console.error(message);
-		});
-
-		process.on('SIGINT', function () {
-			console.error('');
-			process.exit();
-		});
-	}
-
-	return this;
-};
-
-module.exports = function (options) {
-	var updateNotifier = new UpdateNotifier(options);
+export default function updateNotifier(options) {
+	const updateNotifier = new UpdateNotifier(options);
 	updateNotifier.check();
 	return updateNotifier;
-};
-
-module.exports.UpdateNotifier = UpdateNotifier;
+}

license

@@ -0,0 +1,9 @@
+MIT License
+
+Copyright (c) Sindre Sorhus <sindresorhus@gmail.com> (https://sindresorhus.com)
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

package.json

@@ -1,53 +1,67 @@
 {
-  "name": "update-notifier",
-  "version": "1.0.3",
-  "description": "Update notifications for your CLI app",
-  "license": "BSD-2-Clause",
-  "repository": "yeoman/update-notifier",
-  "author": {
-    "name": "Sindre Sorhus",
-    "email": "sindresorhus@gmail.com",
-    "url": "sindresorhus.com"
-  },
-  "engines": {
-    "node": ">=0.10.0"
-  },
-  "scripts": {
-    "test": "if-node-version \">=4\" xo && mocha --timeout 20000"
-  },
-  "files": [
-    "index.js",
-    "check.js"
-  ],
-  "keywords": [
-    "npm",
-    "update",
-    "updater",
-    "notify",
-    "notifier",
-    "check",
-    "checker",
-    "cli",
-    "module",
-    "package",
-    "version"
-  ],
-  "dependencies": {
-    "boxen": "^0.6.0",
-    "chalk": "^1.0.0",
-    "configstore": "^2.0.0",
-    "is-npm": "^1.0.0",
-    "latest-version": "^2.0.0",
-    "lazy-req": "^1.1.0",
-    "semver-diff": "^2.0.0",
-    "xdg-basedir": "^2.0.0"
-  },
-  "devDependencies": {
-    "clear-require": "^1.0.1",
-    "fixture-stdout": "^0.2.1",
-    "if-node-version": "^1.1.0",
-    "mocha": "*",
-    "strip-ansi": "^3.0.1",
-    "xo": "*"
-  }
+	"name": "update-notifier",
+	"version": "6.0.0",
+	"description": "Update notifications for your CLI app",
+	"license": "BSD-2-Clause",
+	"repository": "yeoman/update-notifier",
+	"funding": "https://github.com/yeoman/update-notifier?sponsor=1",
+	"author": {
+		"name": "Sindre Sorhus",
+		"email": "sindresorhus@gmail.com",
+		"url": "https://sindresorhus.com"
+	},
+	"type": "module",
+	"exports": "./index.js",
+	"engines": {
+		"node": ">=14.16"
+	},
+	"scripts": {
+		"test": "xo && ava"
+	},
+	"files": [
+		"index.js",
+		"update-notifier.js",
+		"check.js"
+	],
+	"keywords": [
+		"npm",
+		"update",
+		"updater",
+		"notify",
+		"notifier",
+		"check",
+		"checker",
+		"cli",
+		"module",
+		"package",
+		"version"
+	],
+	"dependencies": {
+		"boxen": "^7.0.0",
+		"chalk": "^5.0.1",
+		"configstore": "^6.0.0",
+		"has-yarn": "^3.0.0",
+		"import-lazy": "^4.0.0",
+		"is-ci": "^3.0.1",
+		"is-installed-globally": "^0.4.0",
+		"is-npm": "^6.0.0",
+		"is-yarn-global": "^0.4.0",
+		"latest-version": "^6.0.0",
+		"pupa": "^3.1.0",
+		"semver": "^7.3.7",
+		"semver-diff": "^4.0.0",
+		"xdg-basedir": "^5.1.0"
+	},
+	"devDependencies": {
+		"ava": "^4.3.0",
+		"clear-module": "^4.1.2",
+		"fixture-stdout": "^0.2.1",
+		"mock-require": "^3.0.3",
+		"strip-ansi": "^7.0.1",
+		"xo": "^0.50.0"
+	},
+	"ava": {
+		"timeout": "20s",
+		"serial": true
+	}
 }

readme.md

@@ -1,38 +1,45 @@
-# update-notifier [![Build Status](https://travis-ci.org/yeoman/update-notifier.svg?branch=master)](https://travis-ci.org/yeoman/update-notifier)
+# update-notifier
 
 > Update notifications for your CLI app
 
 ![](screenshot.png)
 
 Inform users of your package of updates in a non-intrusive way.
 
-#### Table of Contents
+#### Contents
 
-- [Examples](#examples)
+- [Install](#install)
+- [Usage](#usage)
 - [How](#how)
 - [API](#api)
 - [About](#about)
+- [Users](#users)
 
+## Install
 
-## Examples
+```sh
+npm install update-notifier
+```
+
+## Usage
 
-### Simple example
+### Simple
 
 ```js
-const updateNotifier = require('update-notifier');
-const pkg = require('./package.json');
+import updateNotifier from 'update-notifier';
+import packageJson from './package.json' assert {type: 'json'};
 
-updateNotifier({pkg}).notify();
+updateNotifier({pkg: packageJson}).notify();
 ```
 
-### Comprehensive example
+### Comprehensive
 
 ```js
-const updateNotifier = require('update-notifier');
-const pkg = require('./package.json');
+import updateNotifier from 'update-notifier';
+import packageJson from './package.json' assert {type: 'json'};
 
 // Checks for available update and returns an instance
-const notifier = updateNotifier({pkg});
+const notifier = updateNotifier({pkg: packageJson});
 
 // Notify using the built-in convenience method
 notifier.notify();
@@ -43,120 +50,174 @@ console.log(notifier.update);
 {
 	latest: '1.0.1',
 	current: '1.0.0',
-	type: 'patch', // possible values: latest, major, minor, patch, prerelease, build
+	type: 'patch', // Possible values: latest, major, minor, patch, prerelease, build
 	name: 'pageres'
 }
 */
 ```
 
-### Example with settings and custom message
+### Options and custom message
 
 ```js
 const notifier = updateNotifier({
 	pkg,
 	updateCheckInterval: 1000 * 60 * 60 * 24 * 7 // 1 week
 });
 
-console.log(`Update available: ${notifier.update.latest}`);
+if (notifier.update) {
+	console.log(`Update available: ${notifier.update.latest}`);
+}
 ```
 
-
 ## How
 
-Whenever you initiate the update notifier and it's not within the interval threshold, it will asynchronously check with npm in the background for available updates, then persist the result. The next time the notifier is initiated the result will be loaded into the `.update` property. This prevents any impact on your package startup performance.
-The check process is done in a unref'ed [child process](http://nodejs.org/api/child_process.html#child_process_child_process_spawn_command_args_options). This means that if you call `process.exit`, the check will still be performed in its own process.
+Whenever you initiate the update notifier and it's not within the interval threshold, it will asynchronously check with npm in the background for available updates, then persist the result. The next time the notifier is initiated, the result will be loaded into the `.update` property. This prevents any impact on your package startup performance.
+The update check is done in a unref'ed [child process](https://nodejs.org/api/child_process.html#child_process_child_process_spawn_command_args_options). This means that if you call `process.exit`, the check will still be performed in its own process.
 
+The first time the user runs your app, it will check for an update, and even if an update is available, it will wait the specified `updateCheckInterval` before notifying the user. This is done to not be annoying to the user, but might surprise you as an implementer if you're testing whether it works. Check out [`example.js`](example.js) to quickly test out `update-notifier` and see how you can test that it works in your app.
 
 ## API
 
-### updateNotifier(options)
+### notifier = updateNotifier(options)
 
-Checks if there is an available update. Accepts settings defined below. Returns an object with update info if there is an available update, otherwise `undefined`.
+Checks if there is an available update. Accepts options defined below. Returns an instance with an `.update` property if there is an available update, otherwise `undefined`.
 
 ### options
 
+Type: `object`
+
 #### pkg
 
 Type: `object`
 
 ##### name
 
-*Required*<br>
+*Required*\
 Type: `string`
 
 ##### version
 
-*Required*<br>
+*Required*\
 Type: `string`
 
 #### updateCheckInterval
 
-Type: `number`<br>
-Default: 1000 * 60 * 60 * 24 (1 day)
+Type: `number`\
+Default: `1000 * 60 * 60 * 24` *(1 day)*
 
 How often to check for updates.
 
-#### callback(error, update)
+#### shouldNotifyInNpmScript
+
+Type: `boolean`\
+Default: `false`
 
-Type: `function`<br>
+Allows notification to be shown when running as an npm script.
 
-Passing a callback here will make it check for an update directly and report right away. Not recommended as you won't get the benefits explained in [`How`](#how).
+#### distTag
 
-`update` is equal to `notifier.update`
+Type: `string`\
+Default: `'latest'`
 
+Which [dist-tag](https://docs.npmjs.com/adding-dist-tags-to-packages) to use to find the latest version.
 
-### updateNotifier.notify([options])
+### notifier.fetchInfo()
 
-Convenience method to display a notification message *(see screenshot)*.
+Check update information.
 
-Only notifies if there is an update and the process is [TTY](http://nodejs.org/api/tty.html).
+Returns an `object` with:
+
+- `latest` _(String)_ - Latest version.
+- `current` _(String)_ - Current version.
+- `type` _(String)_ - Type of current update. Possible values: `latest`, `major`, `minor`, `patch`, `prerelease`, `build`.
+- `name` _(String)_ - Package name.
+
+### notifier.notify(options?)
+
+Convenience method to display a notification message. *(See screenshot)*
+
+Only notifies if there is an update and the process is [TTY](https://nodejs.org/api/process.html#process_a_note_on_process_i_o).
+
+#### options
+
+Type: `object`
 
-#### options.defer
+##### defer
 
-Type: `boolean`<br>
+Type: `boolean`\
 Default: `true`
 
 Defer showing the notification to after the process has exited.
 
-#### options.message
+##### message
 
-Type: `string`<br>
-Default: [See the screen shot above](https://github.com/yeoman/update-notifier#update-notifier-)
+Type: `string`\
+Default: [See above screenshot](https://github.com/yeoman/update-notifier#update-notifier-)
 
-The message that will be shown when an update is available.
+Message that will be shown when an update is available.
 
-#### options.boxenOpts
+Available placeholders:
 
-Type: `object`<br>
-Default: `{ padding: 1, margin: 1, align: 'center', borderColor: 'yellow', borderStyle: 'round' }` ([See the screen shot above](https://github.com/yeoman/update-notifier#update-notifier-))
+- `{packageName}` - Package name.
+- `{currentVersion}` - Current version.
+- `{latestVersion}` - Latest version.
+- `{updateCommand}` - Update command.
 
-The object that will be passed to [boxen](https://github.com/sindresorhus/boxen).
+```js
+notifier.notify({message: 'Run `{updateCommand}` to update.'});
 
-### User settings
+// Output:
+// Run `npm install update-notifier-tester@1.0.0` to update.
+```
 
-Users of your module have the ability to opt-out of the update notifier by changing the `optOut` property to `true` in `~/.config/configstore/update-notifier-[your-module-name].yml`. The path is available in `notifier.config.path`.
+##### isGlobal
 
-Users can also opt-out by [setting the environment variable](https://github.com/sindresorhus/guides/blob/master/set-environment-variables.md) `NO_UPDATE_NOTIFIER` with any value or by using the `--no-update-notifier` flag on a per run basis.
+Type: `boolean`\
+Default: Auto-detect
 
+Include the `-g` argument in the default message's `npm i` recommendation. You may want to change this if your CLI package can be installed as a dependency of another project, and don't want to recommend a global installation. This option is ignored if you supply your own `message` (see above).
 
-## About
+##### boxenOptions
 
-The idea for this module came from the desire to apply the browser update strategy to CLI tools, where everyone is always on the latest version. We first tried automatic updating, which we discovered wasn't popular. This is the second iteration of that idea, but limited to just update notifications.
+Type: `object`\
+Default: `{padding: 1, margin: 1, textAlignment: 'center', borderColor: 'yellow', borderStyle: 'round'}` *(See screenshot)*
 
-There are a bunch projects using it:
+Options object that will be passed to [`boxen`](https://github.com/sindresorhus/boxen).
+
+### User settings
+
+Users of your module have the ability to opt-out of the update notifier by changing the `optOut` property to `true` in `~/.config/configstore/update-notifier-[your-module-name].json`. The path is available in `notifier.config.path`.
 
-- [Yeoman](http://yeoman.io) - Modern workflows for modern webapps
-- [AVA](https://ava.li) - Simple concurrent test runner
-- [XO](https://github.com/sindresorhus/xo) - JavaScript happiness style linter
-- [Pageres](https://github.com/sindresorhus/pageres) - Capture website screenshots
-- [Node GH](http://nodegh.io) - GitHub command line tool
-- [Bower](http://bower.io) - A package manager for the web
-- [Hoodie CLI](http://hood.ie) - Hoodie command line tool
-- [Roots](http://roots.cx) - A toolkit for advanced front-end development
+Users can also opt-out by [setting the environment variable](https://github.com/sindresorhus/guides/blob/main/set-environment-variables.md) `NO_UPDATE_NOTIFIER` with any value or by using the `--no-update-notifier` flag on a per run basis.
 
-[And 600+ more...](https://www.npmjs.org/browse/depended/update-notifier)
+The check is also skipped automatically:
+  - on CI
+  - in unit tests (when the `NODE_ENV` environment variable is `test`)
 
+## About
 
-## License
+The idea for this module came from the desire to apply the browser update strategy to CLI tools, where everyone is always on the latest version. We first tried automatic updating, which we discovered wasn't popular. This is the second iteration of that idea, but limited to just update notifications.
+
+## Users
+
+There are a bunch projects using it:
 
-[BSD license](http://opensource.org/licenses/bsd-license.php) and copyright Google
+- [npm](https://github.com/npm/npm) - Package manager for JavaScript
+- [Yeoman](https://yeoman.io) - Modern workflows for modern webapps
+- [AVA](https://avajs.dev) - Simple concurrent test runner
+- [XO](https://github.com/xojs/xo) - JavaScript happiness style linter
+- [Node GH](https://github.com/node-gh/gh) - GitHub command line tool
+
+[And 2700+ more…](https://www.npmjs.org/browse/depended/update-notifier)
+
+---
+
+<div align="center">
+	<b>
+		<a href="https://tidelift.com/subscription/pkg/npm-update_notifier?utm_source=npm-update-notifier&utm_medium=referral&utm_campaign=readme">Get professional support for this package with a Tidelift subscription</a>
+	</b>
+	<br>
+	<sub>
+		Tidelift helps make open source sustainable for maintainers while giving companies<br>assurances about security, maintenance, and licensing for their dependencies.
+	</sub>
+</div>

test/fs-error.js

@@ -0,0 +1,20 @@
+import process from 'node:process';
+import clearModule from 'clear-module';
+import test from 'ava';
+
+for (const name of ['..', 'configstore', 'xdg-basedir']) {
+	clearModule(name);
+}
+
+// Set configstore.config to something that requires root access
+process.env.XDG_CONFIG_HOME = '/usr';
+const {default: updateNotifier} = await import('../index.js');
+
+test('fail gracefully', t => {
+	t.notThrows(() => {
+		updateNotifier({
+			packageName: 'npme',
+			packageVersion: '3.7.0',
+		});
+	});
+});

test/notify.js

@@ -0,0 +1,147 @@
+import process from 'node:process';
+import {inherits} from 'node:util';
+import clearModule from 'clear-module';
+import FixtureStdout from 'fixture-stdout';
+import stripAnsi from 'strip-ansi';
+import test from 'ava';
+import mock from 'mock-require';
+
+const stderr = new FixtureStdout({
+	stream: process.stderr,
+});
+
+function Control(shouldNotifyInNpmScript) {
+	this._packageName = 'update-notifier-tester';
+	this.update = {
+		current: '0.0.2',
+		latest: '1.0.0',
+	};
+	this._shouldNotifyInNpmScript = shouldNotifyInNpmScript;
+}
+
+const setupTest = async isNpmReturnValue => {
+	for (const name of ['..', 'is-npm']) {
+		clearModule(name);
+	}
+
+	process.stdout.isTTY = true;
+
+	// TODO: Switch to https://github.com/iambumblehead/esmock
+	mock('is-npm', {isNpmOrYarn: isNpmReturnValue || false});
+
+	const {default: UpdateNotifier} = await import('../update-notifier.js');
+	inherits(Control, UpdateNotifier);
+};
+
+let errorLogs = '';
+
+test.beforeEach(async () => {
+	await setupTest();
+
+	stderr.capture(s => {
+		errorLogs += s;
+		return false;
+	});
+});
+
+test.afterEach(() => {
+	mock.stopAll();
+	stderr.release();
+	errorLogs = '';
+});
+
+test.failing('use pretty boxen message by default', t => {
+	const notifier = new Control();
+	notifier.notify({defer: false, isGlobal: true});
+
+	console.log('d', errorLogs);
+
+	t.is(stripAnsi(errorLogs), `
+   ╭───────────────────────────────────────────────────╮
+   │                                                   │
+   │          Update available 0.0.2 → 1.0.0           │
+   │   Run npm i -g update-notifier-tester to update   │
+   │                                                   │
+   ╰───────────────────────────────────────────────────╯
+
+`);
+});
+
+test.failing('supports custom message', t => {
+	const notifier = new Control();
+	notifier.notify({
+		defer: false,
+		isGlobal: true,
+		message: 'custom message',
+	});
+
+	t.true(stripAnsi(errorLogs).includes('custom message'));
+});
+
+test.failing('supports message with placeholders', t => {
+	const notifier = new Control();
+	notifier.notify({
+		defer: false,
+		isGlobal: true,
+		message: [
+			'Package Name: {packageName}',
+			'Current Version: {currentVersion}',
+			'Latest Version: {latestVersion}',
+			'Update Command: {updateCommand}',
+		].join('\n'),
+	});
+
+	t.is(stripAnsi(errorLogs), `
+   ╭─────────────────────────────────────────────────────╮
+   │                                                     │
+   │        Package Name: update-notifier-tester         │
+   │               Current Version: 0.0.2                │
+   │                Latest Version: 1.0.0                │
+   │   Update Command: npm i -g update-notifier-tester   │
+   │                                                     │
+   ╰─────────────────────────────────────────────────────╯
+
+`);
+});
+
+test.failing('exclude -g argument when `isGlobal` option is `false`', t => {
+	const notifier = new Control();
+	notifier.notify({defer: false, isGlobal: false});
+	t.not(stripAnsi(errorLogs).indexOf('Run npm i update-notifier-tester to update'), -1);
+});
+
+test.failing('shouldNotifyInNpmScript should default to false', t => {
+	const notifier = new Control();
+	notifier.notify({defer: false});
+	t.not(stripAnsi(errorLogs).indexOf('Update available'), -1);
+});
+
+test('suppress output when running as npm script', t => {
+	setupTest(true);
+	const notifier = new Control();
+	notifier.notify({defer: false});
+	t.false(stripAnsi(errorLogs).includes('Update available'));
+});
+
+test('should output if running as npm script and shouldNotifyInNpmScript option set', t => {
+	setupTest(true);
+	const notifier = new Control(true);
+	notifier.notify({defer: false});
+	t.true(stripAnsi(errorLogs).includes('Update available'));
+});
+
+test('should not output if current version is the latest', t => {
+	setupTest(true);
+	const notifier = new Control(true);
+	notifier.update.current = '1.0.0';
+	notifier.notify({defer: false});
+	t.false(stripAnsi(errorLogs).includes('Update available'));
+});
+
+test('should not output if current version is more recent than the reported latest', t => {
+	setupTest(true);
+	const notifier = new Control(true);
+	notifier.update.current = '1.0.1';
+	notifier.notify({defer: false});
+	t.false(stripAnsi(errorLogs).includes('Update available'));
+});

test/update-notifier.js

@@ -0,0 +1,63 @@
+import process from 'node:process';
+import fs from 'node:fs';
+import test from 'ava';
+import mockRequire from 'mock-require';
+import updateNotifier from '../index.js';
+
+mockRequire('is-ci', false);
+
+const generateSettings = (options = {}) => ({
+	pkg: {
+		name: 'update-notifier-tester',
+		version: '0.0.2',
+	},
+	distTag: options.distTag,
+});
+
+let argv;
+let configstorePath;
+
+test.beforeEach(() => {
+	// Prevents NODE_ENV 'test' default behavior which disables `update-notifier`
+	process.env.NODE_ENV = 'ava-test';
+
+	argv = [...process.argv];
+	configstorePath = updateNotifier(generateSettings()).config.path;
+});
+
+test.afterEach(() => {
+	delete process.env.NO_UPDATE_NOTIFIER;
+	process.argv = argv;
+	setTimeout(() => {
+		fs.unlinkSync(configstorePath);
+	}, 10_000);
+});
+
+test('fetch info', async t => {
+	const update = await updateNotifier(generateSettings()).fetchInfo();
+	console.log(update);
+	t.is(update.latest, '0.0.2');
+});
+
+test('fetch info with dist-tag', async t => {
+	const update = await updateNotifier(generateSettings({distTag: '0.0.3-rc1'})).fetchInfo();
+	t.is(update.latest, '0.0.3-rc1');
+});
+
+test('don\'t initialize configStore when NO_UPDATE_NOTIFIER is set', t => {
+	process.env.NO_UPDATE_NOTIFIER = '1';
+	const notifier = updateNotifier(generateSettings());
+	t.is(notifier.config, undefined);
+});
+
+test('don\'t initialize configStore when --no-update-notifier is set', t => {
+	process.argv.push('--no-update-notifier');
+	const notifier = updateNotifier(generateSettings());
+	t.is(notifier.config, undefined);
+});
+
+test('don\'t initialize configStore when NODE_ENV === "test"', t => {
+	process.env.NODE_ENV = 'test';
+	const notifier = updateNotifier(generateSettings());
+	t.is(notifier.config, undefined);
+});

update-notifier.js

@@ -0,0 +1,193 @@
+import process from 'node:process';
+import {spawn} from 'node:child_process';
+import {fileURLToPath} from 'node:url';
+import path from 'node:path';
+import {format} from 'node:util';
+import ConfigStore from 'configstore';
+import chalk from 'chalk';
+import semver from 'semver';
+import semverDiff from 'semver-diff';
+import latestVersion from 'latest-version';
+import {isNpmOrYarn} from 'is-npm';
+import isInstalledGlobally from 'is-installed-globally';
+import isYarnGlobal from 'is-yarn-global';
+import hasYarn from 'has-yarn';
+import boxen from 'boxen';
+import {xdgConfig} from 'xdg-basedir';
+import isCi from 'is-ci';
+import pupa from 'pupa';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+
+const ONE_DAY = 1000 * 60 * 60 * 24;
+
+export default class UpdateNotifier {
+	// Public
+	config;
+	update;
+
+	// Semi-private (used for tests)
+	_packageName;
+	_shouldNotifyInNpmScript;
+
+	#options;
+	#packageVersion;
+	#updateCheckInterval;
+	#isDisabled;
+
+	constructor(options = {}) {
+		this.#options = options;
+		options.pkg = options.pkg || {};
+		options.distTag = options.distTag || 'latest';
+
+		// Reduce pkg to the essential keys. with fallback to deprecated options
+		// TODO: Remove deprecated options at some point far into the future
+		options.pkg = {
+			name: options.pkg.name || options.packageName,
+			version: options.pkg.version || options.packageVersion,
+		};
+
+		if (!options.pkg.name || !options.pkg.version) {
+			throw new Error('pkg.name and pkg.version required');
+		}
+
+		this._packageName = options.pkg.name;
+		this.#packageVersion = options.pkg.version;
+		this.#updateCheckInterval = typeof options.updateCheckInterval === 'number' ? options.updateCheckInterval : ONE_DAY;
+		this.#isDisabled = 'NO_UPDATE_NOTIFIER' in process.env
+			|| process.env.NODE_ENV === 'test'
+			|| process.argv.includes('--no-update-notifier')
+			|| isCi;
+		this._shouldNotifyInNpmScript = options.shouldNotifyInNpmScript;
+
+		if (!this.#isDisabled) {
+			try {
+				this.config = new ConfigStore(`update-notifier-${this._packageName}`, {
+					optOut: false,
+					// Init with the current time so the first check is only
+					// after the set interval, so not to bother users right away
+					lastUpdateCheck: Date.now(),
+				});
+			} catch {
+				// Expecting error code EACCES or EPERM
+				const message
+					= chalk.yellow(format(' %s update check failed ', options.pkg.name))
+					+ format('\n Try running with %s or get access ', chalk.cyan('sudo'))
+					+ '\n to the local update config store via \n'
+					+ chalk.cyan(format(' sudo chown -R $USER:$(id -gn $USER) %s ', xdgConfig));
+
+				process.on('exit', () => {
+					console.error(boxen(message, {textAlignment: 'center'}));
+				});
+			}
+		}
+	}
+
+	check() {
+		if (
+			!this.config
+			|| this.config.get('optOut')
+			|| this.#isDisabled
+		) {
+			return;
+		}
+
+		this.update = this.config.get('update');
+
+		if (this.update) {
+			// Use the real latest version instead of the cached one
+			this.update.current = this.#packageVersion;
+
+			// Clear cached information
+			this.config.delete('update');
+		}
+
+		// Only check for updates on a set interval
+		if (Date.now() - this.config.get('lastUpdateCheck') < this.#updateCheckInterval) {
+			return;
+		}
+
+		// Spawn a detached process, passing the options as an environment property
+		spawn(process.execPath, [path.join(__dirname, 'check.js'), JSON.stringify(this.#options)], {
+			detached: true,
+			stdio: 'ignore',
+		}).unref();
+	}
+
+	async fetchInfo() {
+		const {distTag} = this.#options;
+		const latest = await latestVersion(this._packageName, {version: distTag});
+
+		return {
+			latest,
+			current: this.#packageVersion,
+			type: semverDiff(this.#packageVersion, latest) || distTag,
+			name: this._packageName,
+		};
+	}
+
+	notify(options) {
+		const suppressForNpm = !this._shouldNotifyInNpmScript && isNpmOrYarn;
+		if (!process.stdout.isTTY || suppressForNpm || !this.update || !semver.gt(this.update.latest, this.update.current)) {
+			return this;
+		}
+
+		options = {
+			isGlobal: isInstalledGlobally,
+			isYarnGlobal: isYarnGlobal(),
+			...options,
+		};
+
+		let installCommand;
+		if (options.isYarnGlobal) {
+			installCommand = `yarn global add ${this._packageName}`;
+		} else if (options.isGlobal) {
+			installCommand = `npm i -g ${this._packageName}`;
+		} else if (hasYarn()) {
+			installCommand = `yarn add ${this._packageName}`;
+		} else {
+			installCommand = `npm i ${this._packageName}`;
+		}
+
+		const defaultTemplate = 'Update available '
+			+ chalk.dim('{currentVersion}')
+			+ chalk.reset(' → ')
+			+ chalk.green('{latestVersion}')
+			+ ' \nRun ' + chalk.cyan('{updateCommand}') + ' to update';
+
+		const template = options.message || defaultTemplate;
+
+		options.boxenOptions = options.boxenOptions || {
+			padding: 1,
+			margin: 1,
+			textAlignment: 'center',
+			borderColor: 'yellow',
+			borderStyle: 'round',
+		};
+
+		const message = boxen(
+			pupa(template, {
+				packageName: this._packageName,
+				currentVersion: this.update.current,
+				latestVersion: this.update.latest,
+				updateCommand: installCommand,
+			}),
+			options.boxenOptions,
+		);
+
+		if (options.defer === false) {
+			console.error(message);
+		} else {
+			process.on('exit', () => {
+				console.error(message);
+			});
+
+			process.on('SIGINT', () => {
+				console.error('');
+				process.exit();
+			});
+		}
+
+		return this;
+	}
+}