This is a testharness.js-based test.
[FAIL] popover anchorElement IDL property returns the anchor element
assert_equals: expected (object) Element node <button id="b1">This is an anchor button</button> but got (undefined) undefined
[FAIL] popover anchorElement is settable
assert_equals: expected (object) Element node <button id="b1">This is an anchor button</button> but got (undefined) undefined
[FAIL] anchorElement affects anchor positioning
assert_equals: expected (object) null but got (undefined) undefined
Harness: the test ran to completion.