Support URL objects (#39)

* Merge upstream

* Support URL objects in FetchRequest. Fixes #38

Author: excid3

__tests__/fetch_request.js

@@ -66,6 +66,11 @@ test('treat method name case-insensitive', async () => {
   }
 })
 
+test('casts URL to String', async () => {
+  const testRequest = new FetchRequest("GET", new URL("http://localhost"))
+  expect(typeof testRequest.originalUrl).toBe("string")
+})
+
 describe('header handling', () => {
   const defaultHeaders = {
     'X-Requested-With': 'XMLHttpRequest',

src/fetch_request.js

@@ -6,7 +6,7 @@ export class FetchRequest {
   constructor (method, url, options = {}) {
     this.method = method
     this.options = options
-    this.originalUrl = url
+    this.originalUrl = url.toString()
   }
 
   async perform () {