| <!DOCTYPE html> |
| <html> |
| <head> |
| <title>Dataset - element.dataset is an instance of DOMStringMap</title> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| </head> |
| <body> |
| <h1>Dataset - element.dataset is an instance of DOMStringMap</h1> |
| <div id="log"></div> |
| <script> |
| test(function() { assert_true(document.createElement("div").dataset instanceof window.DOMStringMap); }, |
| "An elements dataset property is an instance of a DOMStringMap"); |
| test(function() { |
| var dataset = document.createElement("div").dataset; |
| assert_true("toString" in dataset, '"toString" in dataset'); |
| assert_equals(dataset.toString, Object.prototype.toString); |
| assert_false("expando" in dataset, '"expando" in dataset'); |
| assert_equals(dataset.expando, undefined); |
| Object.prototype.expando = 42; |
| assert_true("expando" in dataset, '"expando" in dataset'); |
| assert_equals(dataset.expando, 42); |
| }, "Properties on Object.prototype should shine through."); |
| </script> |
| </body> |
| </html> |
