|  | <!doctype html> | 
|  | <html lang="en"> | 
|  | <head> | 
|  | <meta charset="utf-8"> | 
|  | <title>XMLHttpRequest: progress events grow response body size</title> | 
|  | <script src="/resources/testharness.js"></script> | 
|  | <script src="/resources/testharnessreport.js"></script> | 
|  | <link rel="help" href="https://xhr.spec.whatwg.org/#the-send()-method" data-tested-assertations="following::a[contains(@href,'#make-progress-notifications')]/.. following::a[contains(@href,'#make-progress-notifications')]/../following:p[1]" /> | 
|  | <link rel="help" href="https://xhr.spec.whatwg.org/#make-progress-notifications" data-tested-assertations=".." /> | 
|  | <link rel="help" href="https://xhr.spec.whatwg.org/#handler-xhr-onprogress" data-tested-assertations="/../.." /> | 
|  | <link rel="help" href="https://xhr.spec.whatwg.org/#event-xhr-progress" data-tested-assertations="/../.." /> | 
|  | </head> | 
|  |  | 
|  | <div id="log"></div> | 
|  |  | 
|  | <script> | 
|  |  | 
|  | var test = async_test(); | 
|  |  | 
|  | test.step(function() { | 
|  | var client = new XMLHttpRequest(); | 
|  | var lastSize = 0; | 
|  |  | 
|  | client.onprogress = test.step_func(function() { | 
|  | var currentSize = client.responseText.length; | 
|  |  | 
|  | if (lastSize > 0 && currentSize > lastSize) { | 
|  | // growth from a positive size to bigger! | 
|  |  | 
|  | test.done(); | 
|  | } | 
|  |  | 
|  | lastSize = currentSize; | 
|  | }); | 
|  |  | 
|  | client.onreadystatechange = test.step_func(function() { | 
|  | if (client.readyState === 4) { | 
|  | assert_unreached("onprogress not called multiple times, or response body did not grow."); | 
|  | } | 
|  | }); | 
|  |  | 
|  | client.open("GET", "resources/trickle.py?count=1000"); | 
|  | client.send(null); | 
|  | }); | 
|  | </script> |