Enhanced protocol parsing implementation to fix #4633; (#4639)

Added unit tests;

Co-authored-by: Jay <jasonsaayman@gmail.com>

lib/adapters/xhr.js

@@ -10,6 +10,7 @@ var isURLSameOrigin = require('./../helpers/isURLSameOrigin');
 var transitionalDefaults = require('../defaults/transitional');
 var AxiosError = require('../core/AxiosError');
 var CanceledError = require('../cancel/CanceledError');
+var parseProtocol = require('../helpers/parseProtocol');
 
 module.exports = function xhrAdapter(config) {
   return new Promise(function dispatchXhrRequest(resolve, reject) {
@@ -207,8 +208,7 @@ module.exports = function xhrAdapter(config) {
       requestData = null;
     }
 
-    var tokens = fullPath.split(':', 2);
-    var protocol = tokens.length > 1 && tokens[0];
+    var protocol = parseProtocol(fullPath);
 
     if (protocol && [ 'http', 'https', 'file' ].indexOf(protocol) === -1) {
       reject(new AxiosError('Unsupported protocol ' + protocol + ':', AxiosError.ERR_BAD_REQUEST, config));

lib/helpers/parseProtocol.js

@@ -0,0 +1,6 @@
+'use strict';
+
+module.exports = function parseProtocol(url) {
+  var match = /^([-+\w]{1,25})(:?\/\/|:)/.exec(url);
+  return match && match[1] || '';
+};

test/unit/helpers/parseProtocol.js

@@ -0,0 +1,24 @@
+var assert = require('assert');
+var utils = require('../../../lib/utils');
+var parseProtocol = require('../../../lib/helpers/parseProtocol');
+
+describe('helpers::parseProtocol', function () {
+  it('should parse protocol part if it exists', function () {
+    utils.forEach({
+      'http://username:password@example.com/': 'http',
+      'ftp:google.com': 'ftp',
+      'sms:+15105550101?body=hello%20there': 'sms',
+      'tel:0123456789' : 'tel',
+      '//google.com': '',
+      'google.com': '',
+      'admin://etc/default/grub' : 'admin',
+      'stratum+tcp://server:port': 'stratum+tcp',
+      '/api/resource:customVerb': '',
+      'https://stackoverflow.com/questions/': 'https',
+      'mailto:jsmith@example.com' : 'mailto',
+      'chrome-extension://1234/<pageName>.html' : 'chrome-extension'
+    }, (expectedProtocol, url) => {
+      assert.strictEqual(parseProtocol(url), expectedProtocol);
+    });
+  });
+});