<!doctype html> <link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1561283"> <link rel="help" href="https://drafts.csswg.org/css-display/#valdef-display-contents"> <link rel="help" href="https://drafts.csswg.org/css-grid/#grid-item-display"> <link rel="author" href="https://mozilla.org" title="Mozilla"> <link rel="author" href="mailto:emilio@crisal.io" title="Emilio Cobos Álvarez"> <link rel="author" href="mailto:obrufau@igalia.com" title="Oriol Brufau"> <script src="/resources/testharness.js"></script> <script src="/resources/testharnessreport.js"></script> <style> .grid { display: grid } </style> <div style="display: grid"> <span id="grid-child"> <span></span> </div> </div> <script> function display(el) { return getComputedStyle(el).display; } test(function() { let child = document.getElementById("grid-child"); let grandChild = child.firstElementChild; assert_equals(display(child), "block", "Grid child should get blockified"); assert_equals(display(grandChild), "inline", "Grid grand-child should not get initially blockified"); child.style.display = "contents"; assert_equals(display(child), "contents", "No reason for it not to become display: contents"); assert_equals(display(grandChild), "block", "Grid grand-child with display: contents parent should get blockified"); child.style.display = ""; assert_equals(display(child), "block", "Grid child should get blockified"); assert_equals(display(grandChild), "inline", "Grid grand-child should get un-blockified when its parent's display stops being `contents`"); }, "Dynamic changes to `display` causing blockification of children are handled correctly"); </script>