observer-callback-arguments.html (893B)
1 <!DOCTYPE HTML> 2 <meta charset=utf-8> 3 <title>IntersectionObserver: callback arguments</title> 4 <link rel="help" href="https://w3c.github.io/IntersectionObserver/#notify-intersection-observers-algo"> 5 <script src="/resources/testharness.js"></script> 6 <script src="/resources/testharnessreport.js"></script> 7 <div id="log"></div> 8 <script> 9 "use strict"; 10 11 async_test(t => { 12 const io = new IntersectionObserver(function(entries, observer) { 13 t.step(() => { 14 assert_equals(this, io); 15 assert_equals(arguments.length, 2); 16 assert_true(Array.isArray(entries)); 17 assert_equals(entries.length, 1); 18 assert_true(entries[0] instanceof IntersectionObserverEntry); 19 assert_equals(observer, io); 20 21 io.disconnect(); 22 t.done(); 23 }); 24 }); 25 26 io.observe(document.body); 27 }, "Callback is invoked with |this| value of IntersectionObserver and two arguments"); 28 </script>