This is with the try build made on Feb 15, 2018. I use NVDA and Firefox on Windows. 1. Open Accessibility Inspector. 2. Navigate to any element, like a link. 3. Tab to the properties tree. Listen to how NVDA speaks items as being level 1. 4. Navigate down to Actions. NVDA will indicate that it is a closed item, meaning it can be expanded. 5. Press RightArrow to expand. 6. Press DownArrow to move to the revealed child element. Expected: NVDA should read this and indicate that it is level 2, as this is a child of a parent item, so a level deeper. Actual: It is still being announced as level 1. Note that the other tree, the tree of accessible objects, gets this right. Child elements are always 1 level deeper (a number higher) than their parent.

Comment on attachment 8953597 [details] [diff] [review] 1438837 patch Review of attachment 8953597 [details] [diff] [review]: ----------------------------------------------------------------- Looks good to me without the CSS change :) ::: devtools/client/shared/components/reps/reps.css @@ +292,5 @@ > } > > /* For non expandable root nodes, we don't have .tree-indent elements, so we declare > the margin on the start of the node */ > +.tree-node[data-expandable="false"][aria-level="1"] { I don't think this is wanted: this file should not be used by the VirtualizedTree, and its source of truth is on Github.

I filed https://github.com/devtools-html/devtools-core/issues/963 to do this on the Tree used by the console and the debugger

Pushed by yura.zenevich@gmail.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/d02fd1a8e0ea fix VirtualizedTree node aria-level attribute to start with 1 not 0. r=nchevobbe