feat: add request cancelation in browser implementation

browser.js

@@ -3,9 +3,9 @@ const isIp = require('is-ip');
 
 const defaults = {
 	timeout: 5000
-};
+  };
 
-const urls = {
+  const urls = {
 	v4: [
 		'https://ipv4.icanhazip.com/',
 		'https://api.ipify.org/'
@@ -16,42 +16,55 @@ const urls = {
 	]
 };
 
-const sendXhr = async (url, options, version) => {
-	return new Promise((resolve, reject) => {
-		const xhr = new XMLHttpRequest();
-		xhr.addEventListener('error', reject, {once: true});
-		xhr.addEventListener('timeout', reject, {once: true});
+  const sendXhr = (url, options, version) => {
+	const xhr = new XMLHttpRequest();
+	let _resolve;
+	const promise = new Promise((resolve, reject) => {
+	  _resolve = resolve;
+	  xhr.addEventListener('error', reject, { once: true });
+	  xhr.addEventListener('timeout', reject, { once: true });
 
-		xhr.addEventListener('load', () => {
-			const ip = xhr.responseText.trim();
+	  xhr.addEventListener('load', () => {
+		  const ip = xhr.responseText.trim();
 
-			if (!ip || !isIp[version](ip)) {
-				reject();
-				return;
-			}
+		  if (!ip || !isIp[version](ip)) {
+			reject();
+			return;
+		  }
 
-			resolve(ip);
+		  resolve(ip);
 		}, {once: true});
 
-		xhr.open('GET', url);
-		xhr.timeout = options.timeout;
-		xhr.send();
+	  xhr.open('GET', url);
+	  xhr.timeout = options.timeout;
+	  xhr.send();
 	});
-};
+	promise.cancel = () => {
+	  _resolve();
+	  xhr.abort();
+	}
+	return promise;
+  };
 
-const queryHttps = async (version, options) => {
-	let ip;
-	const urls_ = [].concat.apply(urls[version], options.fallbackUrls || []);
-	for (const url of urls_) {
+  const queryHttps = (version, options) => {
+	let request;
+	const promise = (async function () {
+	  const urls_ = [].concat.apply(urls[version], options.fallbackUrls || []);
+	  for (const url of urls_) {
 		try {
-			// eslint-disable-next-line no-await-in-loop
-			ip = await sendXhr(url, options, version);
-			return ip;
+		  // eslint-disable-next-line no-await-in-loop
+		  request = sendXhr(url, options, version);
+		  const ip = await request;
+		  return ip;
 		} catch (_) {}
-	}
-
-	throw new Error('Couldn\'t find your IP');
-};
+	  }
+	  throw new Error("Couldn't find your IP");
+	})();
+	promise.cancel = () => {
+	  request.cancel();
+	};
+	return promise;
+  };
 
 module.exports.v4 = options => queryHttps('v4', {...defaults, ...options});