| <!doctype html> | 
 | <html> | 
 | <head> | 
 | <meta charset="utf8"> | 
 | <link rel="help" href="http://url.spec.whatwg.org/#dom-urlsearchparams-append"> | 
 | <script src="/resources/testharness.js"></script> | 
 | <script src="/resources/testharnessreport.js"></script> | 
 | <script> | 
 | test(function() { | 
 |  var params = new URLSearchParams(); | 
 |  params.append('a', 'b'); | 
 |  assert_equals(params + '', 'a=b'); | 
 |  params.append('a', 'b'); | 
 |  assert_equals(params + '', 'a=b&a=b'); | 
 |  params.append('a', 'c'); | 
 |  assert_equals(params + '', 'a=b&a=b&a=c'); | 
 | }, 'Append same name'); | 
 |  | 
 | test(function() { | 
 |  var params = new URLSearchParams(); | 
 |  params.append('', ''); | 
 |  assert_equals(params + '', '='); | 
 |  params.append('', ''); | 
 |  assert_equals(params + '', '=&='); | 
 | }, 'Append empty strings'); | 
 |  | 
 | test(function() { | 
 |  var params = new URLSearchParams(); | 
 |  params.append(null, null); | 
 |  assert_equals(params + '', 'null=null'); | 
 |  params.append(null, null); | 
 |  assert_equals(params + '', 'null=null&null=null'); | 
 | }, 'Append null'); | 
 |  | 
 | test(function() { | 
 |  var params = new URLSearchParams(); | 
 |  params.append('first', 1); | 
 |  params.append('second', 2); | 
 |  params.append('third', ''); | 
 |  params.append('first', 10); | 
 |  assert_true(params.has('first'), 'Search params object has name "first"'); | 
 |  assert_equals(params.get('first'), '1', 'Search params object has name "first" with value "1"'); | 
 |  assert_equals(params.get('second'), '2', 'Search params object has name "second" with value "2"'); | 
 |  assert_equals(params.get('third'), '', 'Search params object has name "third" with value ""'); | 
 |  params.append('first', 10); | 
 |  assert_equals(params.get('first'), '1', 'Search params object has name "first" with value "1"'); | 
 | }, 'Append multiple'); | 
 | </script> | 
 | </head> | 
 | </html> |