|  | <!DOCTYPE html> | 
|  | <meta name="viewport" content="width=device-width,initial-scale=1"> | 
|  | <script src="/resources/testharness.js"></script> | 
|  | <script src="/resources/testharnessreport.js"></script> | 
|  |  | 
|  | <div id="root"></div> | 
|  |  | 
|  | <script> | 
|  | test(function() { | 
|  | var observer = new IntersectionObserver(function(e) {}, {}); | 
|  | test(function() { assert_equals(observer.root, null) }, | 
|  | "observer.root"); | 
|  | test(function() { assert_array_equals(observer.thresholds, [0]) }, | 
|  | "observer.thresholds"); | 
|  | test(function() { assert_equals(observer.rootMargin, "0px 0px 0px 0px") }, | 
|  | "observer.rootMargin"); | 
|  |  | 
|  | var rootDiv = document.getElementById("root"); | 
|  | observer = new IntersectionObserver(function(e) {}, { | 
|  | root: rootDiv, | 
|  | threshold: [0, 0.25, 0.5, 1.0], | 
|  | rootMargin: "10% 20px" | 
|  | }); | 
|  | test(function() { assert_equals(observer.root, rootDiv) }, | 
|  | "set observer.root"); | 
|  | test(function() { assert_array_equals(observer.thresholds, [0, 0.25, 0.5, 1.0]) }, | 
|  | "set observer.thresholds"); | 
|  | test(function() { assert_equals(observer.rootMargin, "10% 20px 10% 20px") }, | 
|  | "set observer.rootMargin"); | 
|  | }, "Observer attribute getters."); | 
|  |  | 
|  | </script> |