Merge pull request #542 from TrevorBurnham/role-supports-aria-props-null

Allow role-incompatible props to be null/undefined

Author: jessebeach

__tests__/src/rules/role-supports-aria-props-test.js

@@ -379,6 +379,10 @@ ruleTester.run('role-supports-aria-props', rule, {
     { code: '<input type="url" aria-disabled />' },
     { code: '<input aria-disabled />' },
 
+    // Allow null/undefined values regardless of role
+    { code: '<h2 role="presentation" aria-level={null} />' },
+    { code: '<h2 role="presentation" aria-level={undefined} />' },
+
     // OTHER TESTS
     { code: '<aside aria-expanded />' },
     { code: '<article aria-expanded />' },

src/rules/role-supports-aria-props.js

@@ -15,6 +15,7 @@ import {
 import {
   getProp,
   getLiteralPropValue,
+  getPropValue,
   elementType,
   propName,
 } from 'jsx-ast-utils';
@@ -67,9 +68,11 @@ module.exports = {
         .filter(attribute => propertySet.indexOf(attribute) === -1);
 
       node.attributes.forEach((prop) => {
-        if (prop.type === 'JSXSpreadAttribute') {
-          return;
-        }
+        // Ignore the attribute if its value is null or undefined.
+        if (getPropValue(prop) == null) return;
+
+        // Ignore the attribute if it's a spread.
+        if (prop.type === 'JSXSpreadAttribute') return;
 
         const name = propName(prop);
         if (invalidAriaPropsForRole.indexOf(name) > -1) {