Improve detection for terminals supporting Unicode

Closes #26

index.d.ts

@@ -8,8 +8,8 @@ Includes fallbacks for Windows CMD which only supports a [limited character set]
 import logSymbols = require('log-symbols');
 
 console.log(logSymbols.success, 'Finished successfully!');
-// On good OSes:  ✔ Finished successfully!
-// On Windows:    √ Finished successfully!
+// Terminals with Unicode support:     ✔ Finished successfully!
+// Terminals without Unicode support:  √ Finished successfully!
 ```
 */
 declare const logSymbols: {

index.js

@@ -1,7 +1,6 @@
 'use strict';
 const chalk = require('chalk');
-
-const isSupported = process.platform !== 'win32' || process.env.CI || process.env.TERM === 'xterm-256color';
+const isUnicodeSupported = require('is-unicode-supported');
 
 const main = {
 	info: chalk.blue('ℹ'),
@@ -10,11 +9,11 @@ const main = {
 	error: chalk.red('✖')
 };
 
-const fallbacks = {
+const fallback = {
 	info: chalk.blue('i'),
 	success: chalk.green('√'),
 	warning: chalk.yellow('‼'),
 	error: chalk.red('×')
 };
 
-module.exports = isSupported ? main : fallbacks;
+module.exports = isUnicodeSupported() ? main : fallback;

package.json

@@ -4,6 +4,7 @@
 	"description": "Colored symbols for various log levels. Example: `✔︎ Success`",
 	"license": "MIT",
 	"repository": "sindresorhus/log-symbols",
+	"funding": "https://github.com/sponsors/sindresorhus",
 	"author": {
 		"name": "Sindre Sorhus",
 		"email": "sindresorhus@gmail.com",
@@ -38,13 +39,14 @@
 		"stdout"
 	],
 	"dependencies": {
-		"chalk": "^4.0.0"
+		"chalk": "^4.1.0",
+		"is-unicode-supported": "^0.1.0"
 	},
 	"devDependencies": {
-		"ava": "^3.7.1",
+		"ava": "^2.4.0",
 		"strip-ansi": "^6.0.0",
-		"tsd": "^0.11.0",
-		"xo": "^0.30.0"
+		"tsd": "^0.14.0",
+		"xo": "^0.38.2"
 	},
 	"browser": "browser.js"
 }

readme.md

@@ -18,8 +18,8 @@ $ npm install log-symbols
 const logSymbols = require('log-symbols');
 
 console.log(logSymbols.success, 'Finished successfully!');
-// On good OSes:  ✔ Finished successfully!
-// On Windows:    √ Finished successfully!
+// Terminals with Unicode support:     ✔ Finished successfully!
+// Terminals without Unicode support:  √ Finished successfully!
 ```
 
 ## API