AC-954: Create unit test for Magento2\Less\TypeSelectorsSniff check

Magento2/Tests/Less/TypeSelectorsUnitTest.less

@@ -0,0 +1,23 @@
+// /**
+//  * Copyright © Magento, Inc. All rights reserved.
+//  * See COPYING.txt for license details.
+//  */
+
+.error {
+  some: 'stuff';
+}
+
+/**
+ * Should throw an error, Will be implemented in MAGETWO-49778
+ */
+div.error {
+  anything: 'else';
+}
+
+.nav > LI {
+  #bar .baz();
+}
+
+.nav > ul {
+  foo: 'bar';
+}

Magento2/Tests/Less/TypeSelectorsUnitTest.php

@@ -0,0 +1,27 @@
+<?php
+/**
+ * Copyright © Magento. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace Magento2\Tests\Less;
+
+class TypeSelectorsUnitTest extends AbstractLessSniffUnitTestCase
+{
+    /**
+     * @inheritdoc
+     */
+    public function getErrorList()
+    {
+        return [
+            17 => 1,
+        ];
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function getWarningList()
+    {
+        return [];
+    }
+}