This is a testharness.js-based test.
[FAIL] item 1
assert_equals: \n<item data-expected-margin-top="0" class="collapsed">\n <item data-expected-margin-top="0" class="collapsed"></item>\n </item>\nmargin-top expected "0" but got "50"
[FAIL] item 2
assert_equals: \n<item data-expected-margin-top="0" class="collapsed"></item>\nmargin-top expected "0" but got "50"
[FAIL] item 3
assert_equals: \n<item class="with-border-and-margin" data-expected-margin-top="0">\n <item class="with-border-and-margin" data-expected-margin-top="30"></item>\n </item>\nmargin-top expected "0" but got "30"
[FAIL] item 4
assert_equals: \n<item class="with-border-and-margin" data-expected-margin-top="30"></item>\nmargin-top expected "0" but got "30"
Harness: the test ran to completion.