Require Node.js 18

Closes #151

.github/funding.yml

@@ -1,2 +1 @@
 github: [sindresorhus, Qix-]
-tidelift: npm/supports-color

.github/workflows/main.yml

@@ -10,12 +10,11 @@ jobs:
       fail-fast: false
       matrix:
         node-version:
+          - 20
           - 18
-          - 16
-          - 14
     steps:
-      - uses: actions/checkout@v3
-      - uses: actions/setup-node@v3
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
         with:
           node-version: ${{ matrix.node-version }}
       - run: npm install

browser.js

@@ -1,14 +1,18 @@
 /* eslint-env browser */
 
 const level = (() => {
-	if (navigator.userAgentData) {
+	if (!('navigator' in globalThis)) {
+		return 0;
+	}
+
+	if (globalThis.navigator.userAgentData) {
 		const brand = navigator.userAgentData.brands.find(({brand}) => brand === 'Chromium');
 		if (brand?.version > 93) {
 			return 3;
 		}
 	}
 
-	if (/\b(Chrome|Chromium)\//.test(navigator.userAgent)) {
+	if (/\b(Chrome|Chromium)\//.test(globalThis.navigator.userAgent)) {
 		return 1;
 	}
 

index.d.ts

@@ -1,13 +1,13 @@
 import type {WriteStream} from 'node:tty';
 
-export interface Options {
+export type Options = {
 	/**
 	Whether `process.argv` should be sniffed for `--color` and `--no-color` flags.
 
 	@default true
 	*/
 	readonly sniffFlags?: boolean;
-}
+};
 
 /**
 Levels:
@@ -21,7 +21,7 @@ export type ColorSupportLevel = 0 | 1 | 2 | 3;
 /**
 Detect whether the terminal supports color.
 */
-export interface ColorSupport {
+export type ColorSupport = {
 	/**
 	The color level.
 	*/
@@ -41,7 +41,7 @@ export interface ColorSupport {
 	Whether Truecolor 16 million colors are supported.
 	*/
 	has16m: boolean;
-}
+};
 
 export type ColorInfo = ColorSupport | false;
 

index.js

@@ -31,17 +31,29 @@ if (
 }
 
 function envForceColor() {
-	if ('FORCE_COLOR' in env) {
-		if (env.FORCE_COLOR === 'true') {
-			return 1;
-		}
+	if (!('FORCE_COLOR' in env)) {
+		return;
+	}
 
-		if (env.FORCE_COLOR === 'false') {
-			return 0;
-		}
+	if (env.FORCE_COLOR === 'true') {
+		return 1;
+	}
+
+	if (env.FORCE_COLOR === 'false') {
+		return 0;
+	}
 
-		return env.FORCE_COLOR.length === 0 ? 1 : Math.min(Number.parseInt(env.FORCE_COLOR, 10), 3);
+	if (env.FORCE_COLOR.length === 0) {
+		return 1;
 	}
+
+	const level = Math.min(Number.parseInt(env.FORCE_COLOR, 10), 3);
+
+	if (![0, 1, 2, 3].includes(level)) {
+		return;
+	}
+
+	return level;
 }
 
 function translateLevel(level) {

index.test-d.ts

@@ -1,6 +1,6 @@
 import {stdout, stderr} from 'node:process';
 import {expectType} from 'tsd';
-import supportsColor, {createSupportsColor, Options, ColorInfo} from './index.js';
+import supportsColor, {createSupportsColor, type Options, type ColorInfo} from './index.js';
 
 const options: Options = {};
 

package.json

@@ -12,15 +12,16 @@
 	},
 	"type": "module",
 	"exports": {
+		"types": "./index.d.ts",
 		"node": "./index.js",
 		"default": "./browser.js"
 	},
+	"sideEffects": false,
 	"engines": {
-		"node": ">=12"
+		"node": ">=18"
 	},
 	"scripts": {
-		"//test": "xo && ava && tsd",
-		"test": "tsd"
+		"test": "xo && ava && tsd"
 	},
 	"files": [
 		"index.js",
@@ -51,10 +52,13 @@
 		"16m"
 	],
 	"devDependencies": {
-		"@types/node": "^20.3.2",
-		"ava": "^5.3.1",
-		"import-fresh": "^3.3.0",
-		"tsd": "^0.18.0",
-		"xo": "^0.54.2"
+		"@types/node": "^20.11.17",
+		"ava": "^6.1.1",
+		"tsd": "^0.30.4",
+		"xo": "^0.57.0"
+	},
+	"ava": {
+		"serial": true,
+		"workerThreads": false
 	}
 }

readme.md

@@ -4,8 +4,8 @@
 
 ## Install
 
-```
-$ npm install supports-color
+```sh
+npm install supports-color
 ```
 
 ## Usage
@@ -73,17 +73,3 @@ Explicit 256/Truecolor mode can be enabled using the `--color=256` and `--color=
 
 - [Sindre Sorhus](https://github.com/sindresorhus)
 - [Josh Junon](https://github.com/qix-)
-
----
-
-<div align="center">
-	<b>
-		<a href="https://tidelift.com/subscription/pkg/npm-supports-color?utm_source=npm-supports-color&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>
-
----