fix: don't flag invalid roles in unsupportedrole

lib/checks/aria/unsupportedrole.js

@@ -1,3 +1 @@
-return !axe.commons.aria.isValidRole(node.getAttribute('role'), {
-	flagUnsupported: true
-});
+return axe.commons.aria.isUnsupportedRole(axe.commons.aria.getRole(node));

lib/commons/aria/is-unsupported-role.js

@@ -0,0 +1,14 @@
+/* global aria, axe */
+
+/**
+ * Check if a given role is unsupported
+ * @method isUnsupportedRole
+ * @memberof axe.commons.aria
+ * @instance
+ * @param {String} role The role to check
+ * @return {Boolean}
+ */
+aria.isUnsupportedRole = function(role) {
+	const roleDefinition = aria.lookupTable.role[role];
+	return roleDefinition ? roleDefinition.unsupported : false;
+};

test/checks/aria/unsupportedrole.js

@@ -8,7 +8,7 @@ describe('unsupportedrole', function() {
 	});
 
 	it('should return true if applied to an unsupported role', function() {
-		axe.commons.aria.lookupTable.role.mcheddarton = {
+		axe.commons.aria.lookupTable.role.mccheddarton = {
 			type: 'widget',
 			unsupported: true
 		};
@@ -21,5 +21,15 @@ describe('unsupportedrole', function() {
 		fixture.innerHTML = '<div id="target" role="alert">Contents</div>';
 		var node = fixture.querySelector('#target');
 		assert.isFalse(checks.unsupportedrole.evaluate(node));
+
+		fixture.innerHTML = '<button id="target">Contents</button>';
+		var node = fixture.querySelector('#target');
+		assert.isFalse(checks.unsupportedrole.evaluate(node));
+	});
+
+	it('should return false if applied to an invalid role', function() {
+		fixture.innerHTML = '<input id="target" role="foo">';
+		var node = fixture.querySelector('#target');
+		assert.isFalse(checks.unsupportedrole.evaluate(node));
 	});
 });

test/commons/aria/is-unsupported-role.js

@@ -0,0 +1,32 @@
+describe('aria.isUnsupportedRole', function() {
+	'use strict';
+
+	it('should return true if the role is unsupported', function() {
+		var orig = axe.commons.aria.lookupTable.role;
+		axe.commons.aria.lookupTable.role = {
+			cats: {
+				unsupported: true
+			}
+		};
+		assert.isTrue(axe.commons.aria.isUnsupportedRole('cats'));
+		axe.commons.aria.lookupTable.role = orig;
+	});
+
+	it('should return false if the role is supported', function() {
+		var orig = axe.commons.aria.lookupTable.role;
+		axe.commons.aria.lookupTable.role = {
+			cats: {
+				unsupported: false
+			}
+		};
+		assert.isFalse(axe.commons.aria.isUnsupportedRole('cats'));
+		axe.commons.aria.lookupTable.role = orig;
+	});
+
+	it('should return false if the role is invalid', function() {
+		var orig = axe.commons.aria.lookupTable.role;
+		axe.commons.aria.lookupTable.role = {};
+		assert.isFalse(axe.commons.aria.isUnsupportedRole('cats'));
+		axe.commons.aria.lookupTable.role = orig;
+	});
+});