Fix collapse, group skew, empty tables and the tab strip scrollbar

frontend/src/components/pluginAssetPanels.spec.js

@@ -327,3 +327,16 @@ describe('facet chips on a card that shows a health dot', () => {
     expect(facetedRows(services, ['Start Pending']).length).toBe(1)
   })
 })
+
+describe('panelVisible and empty', () => {
+  it('keeps a table panel that declares an empty message', () => {
+    // It is the only card in the Software tab, so hiding it hides the tab and
+    // the reader cannot tell "nothing reported" from "feature missing".
+    const panel = { render: 'table', _data: { items: [] }, empty: 'No installed software reported.' }
+    expect(panelVisible(panel)).toBe(true)
+  })
+
+  it('still hides a table panel with nothing to say', () => {
+    expect(panelVisible({ render: 'table', _data: { items: [] } })).toBe(false)
+  })
+})