This test checks if offsetParent is always null when accessed from the HTML <body> and from elements with CSS property position:fixed. To ensure values match layout, this test also checks offsetTop and offsetLeft.
In addition to the HTML <body>, two elements with CSS property position:fixed are tested: One within the body, and one within an element with CSS property position:absolute.
Finally, a static- and relative-positioned element are tested for sanity and spec adherence.
Expected values are parenthesized. Test has passed if all values match.