fix(ajax): properly encode body with form data that includes URLs

closes ReactiveX#2399

spec/observables/dom/ajax-spec.ts

@@ -652,6 +652,39 @@ describe('Observable.ajax', () => {
  expect(complete).to.be.true;
  });
 
+ it('should properly encode full URLs passed', () => {
+ const expected = { test: 'https://google.com/search?q=encodeURI+vs+encodeURIComponent' };
+ let result: Rx.AjaxResponse;
+ let complete = false;
+
+ Rx.Observable
+ .ajax.post('/flibbertyJibbet', expected)
+ .subscribe(x => {
+ result = x;
+ }, null, () => {
+ complete = true;
+ });
+
+ const request = MockXMLHttpRequest.mostRecent;
+
+ expect(request.method).to.equal('POST');
+ expect(request.url).to.equal('/flibbertyJibbet');
+ expect(request.requestHeaders).to.deep.equal({
+ 'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8'
+ });
+
+ request.respondWith({
+ 'status': 200,
+ 'contentType': 'application/json',
+ 'responseText': JSON.stringify(expected)
+ });
+
+ expect(request.data)
+ .to.equal('test=https%3A%2F%2Fgoogle.com%2Fsearch%3Fq%3DencodeURI%2Bvs%2BencodeURIComponent');
+ expect(result.response).to.deep.equal(expected);
+ expect(complete).to.be.true;
+ });
+
  it('should succeed on 204 No Content', () => {
  const expected = null;
  let result: Rx.AjaxResponse;

src/internal/observable/dom/AjaxObservable.ts

@@ -292,7 +292,7 @@ export class AjaxSubscriber<T> extends Subscriber<Event> {
 
  switch (contentType) {
  case 'application/x-www-form-urlencoded':
- return Object.keys(body).map(key => `${encodeURI(key)}=${encodeURI(body[key])}`).join('&');
+ return Object.keys(body).map(key => `${encodeURIComponent(key)}=${encodeURIComponent(body[key])}`).join('&');
  case 'application/json':
  return JSON.stringify(body);
  default: