| <!DOCTYPE html> |
| <html> |
| <head> |
| <meta charset="utf-8" /> |
| <title>window.performance.now() chronology</title> |
| <link rel="author" title="W3C" href="http://www.w3.org/" /> |
| <link rel="help" href="http://www.w3.org/TR/hr-time/#sec-monotonic-clock"/> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <link rel="stylesheet" href="/resources/testharness.css" /> |
| <script> |
| test(function() { |
| assert_true(window.performance.now() > 0, "window.performance.now() returns positive numbers"); |
| }, "window.performance.now() returns a positive number", {assert: "The time values returned when calling the now method MUST be monotonically increasing and not subject to system clock adjustments or system clock skew."}); |
| |
| test(function() { |
| var now1 = window.performance.now(); |
| var now2 = window.performance.now(); |
| assert_true((now2-now1) >= 0, "window.performance.now() difference is not negative"); |
| }, |
| "window.performance.now() difference is not negative", |
| { |
| assert: "The difference between any two chronologically recorded time values returned from the now method MUST never be negative." |
| } |
| ); |
| |
| </script> |
| </head> |
| <body> |
| <h1>Description</h1> |
| <p>This test validates that window.performance.now() follows the monotonic clock requirements.</p> |
| |
| <div id="log"></div> |
| |
| </body> |
| </html> |
