fix(get-role): handle presentation role inheritance for vnodes with no parent (#3801)

Author: dbowling

lib/commons/aria/get-role.js

@@ -54,6 +54,10 @@ function getInheritedRole(vNode, explicitRoleOptions) {
   // if we can't look at the parent then we can't know if the node
   // inherits the presentational role or not
   if (!vNode.parent) {
+    if (!vNode.actualNode) {
+      return null;
+    }
+
     throw new ReferenceError(
       'Cannot determine role presentational inheritance of a required parent outside the current scope.'
     );

lib/rules/empty-table-header.json

@@ -1,6 +1,6 @@
 {
   "id": "empty-table-header",
-  "selector": "th, [role=\"rowheader\"], [role=\"columnheader\"]",
+  "selector": "th:not([role]), [role=\"rowheader\"], [role=\"columnheader\"]",
   "tags": ["cat.name-role-value", "best-practice"],
   "metadata": {
     "description": "Ensures table headers have discernible text",

test/commons/aria/get-role.js

@@ -412,4 +412,26 @@ describe('aria.getRole', function () {
       assert.isNull(aria.getRole(node, { noPresentational: true }));
     });
   });
+
+  describe('SerialVirtualNode', function () {
+    it('works with the SerialVirtualNode', function () {
+      var vNode = new axe.SerialVirtualNode({
+        nodeName: 'div',
+        attributes: {
+          role: 'button'
+        }
+      });
+      assert.equal(aria.getRole(vNode), 'button');
+    });
+
+    it('does not throw for missing parent in presentational role inheritance', function () {
+      var vNode = new axe.SerialVirtualNode({
+        nodeName: 'li'
+      });
+
+      assert.doesNotThrow(function () {
+        assert.equal(aria.getRole(vNode), 'listitem');
+      });
+    });
+  });
 });

test/integration/rules/empty-table-header/empty-table-header.html

@@ -45,5 +45,11 @@
         </td>
       </tr>
     </table>
+
+    <table>
+      <tr>
+        <th id="ignore1" role="spinbutton">rowheader with a role</th>
+      </tr>
+    </table>
   </body>
 </html>

test/integration/virtual-rules/empty-table-header.js

@@ -1,17 +1,61 @@
 describe('empty-table-header virtual-rule', function () {
-  it('should incomplete when children are missing', function () {
+  it('should fail when children contain no visible text', function () {
     var thNode = new axe.SerialVirtualNode({
       nodeName: 'th'
     });
     thNode.children = [];
 
     var results = axe.runVirtualRule('empty-table-header', thNode);
 
+    assert.lengthOf(results.passes, 0);
+    assert.lengthOf(results.violations, 1);
+    assert.lengthOf(results.incomplete, 0);
+  });
+
+  it('should incomplete when children are missing', function () {
+    var thNode = new axe.SerialVirtualNode({
+      nodeName: 'th'
+    });
+
+    var results = axe.runVirtualRule('empty-table-header', thNode);
+
     assert.lengthOf(results.passes, 0);
     assert.lengthOf(results.violations, 0);
     assert.lengthOf(results.incomplete, 1);
   });
 
+  it('should fail for role=rowheader', function () {
+    var vNode = new axe.SerialVirtualNode({
+      nodeName: 'div',
+      attributes: {
+        role: 'rowheader'
+      }
+    });
+    vNode.children = [];
+
+    var results = axe.runVirtualRule('empty-table-header', vNode);
+
+    assert.lengthOf(results.passes, 0);
+    assert.lengthOf(results.violations, 1);
+    assert.lengthOf(results.incomplete, 0);
+  });
+
+  it('should fail for role=columnheader', function () {
+    var vNode = new axe.SerialVirtualNode({
+      nodeName: 'div',
+      attributes: {
+        role: 'columnheader'
+      }
+    });
+    vNode.children = [];
+
+    var results = axe.runVirtualRule('empty-table-header', vNode);
+
+    assert.lengthOf(results.passes, 0);
+    assert.lengthOf(results.violations, 1);
+    assert.lengthOf(results.incomplete, 0);
+  });
+
   it('should pass with a table header', function () {
     var tableNode = new axe.SerialVirtualNode({
       nodeName: 'table'
@@ -137,19 +181,33 @@ describe('empty-table-header virtual-rule', function () {
     assert.lengthOf(results.incomplete, 0);
   });
 
-  it('should fail if table header has no child nodes', function () {
-    var node = new axe.SerialVirtualNode({
+  it('should be inapplicable when the th has role of cell', function () {
+    var table = new axe.SerialVirtualNode({
+      nodeName: 'table'
+    });
+
+    var tr = new axe.SerialVirtualNode({
+      nodeName: 'tr'
+    });
+
+    var th = new axe.SerialVirtualNode({
       nodeName: 'th',
       attributes: {
-        role: 'rowheader'
+        role: 'cell'
       }
     });
-    node.children = [];
 
-    var results = axe.runVirtualRule('empty-table-header', node);
+    tr.children = [th];
+    tr.parent = table;
+    th.parent = tr;
+    th.children = [];
+    table.children = [tr];
+
+    var results = axe.runVirtualRule('empty-table-header', th);
 
     assert.lengthOf(results.passes, 0);
-    assert.lengthOf(results.violations, 1);
+    assert.lengthOf(results.violations, 0);
     assert.lengthOf(results.incomplete, 0);
+    assert.lengthOf(results.inapplicable, 1);
   });
 });