<!DOCTYPE html> <html> <head> <title>XMLHttpRequest: getResponseHeader() in unsent, opened states</title> <script src="/resources/testharness.js"></script> <script src="/resources/testharnessreport.js"></script> <link rel="help" href="https://xhr.spec.whatwg.org/#dom-xmlhttprequest-getresponseheader" data-tested-assertations="/following::OL[1]/LI[1]" /> </head> <body> <div id="log"></div> <script> var test = async_test() test.step(function() { var client = new XMLHttpRequest() assert_equals(client.getResponseHeader("x-custom-header"), null) client.onreadystatechange = function() { test.step(function() { if(client.readyState < 2) { assert_equals(client.getResponseHeader("x-custom-header"), null) assert_equals(client.getResponseHeader("CONTENT-TYPE"), null) test.done() } }) } client.open("GET", "resources/headers.py") assert_equals(client.getResponseHeader("x-custom-header"), null) assert_equals(client.getResponseHeader("Date"), null) client.send(null) }) </script> </body> </html>