Added missing test

Author: kukulich

tests/Sniffs/Namespaces/ReferenceUsedNamesOnlySniffTest.php

@@ -529,6 +529,18 @@ public function testIgnoredNamesWithAllowFullyQualifiedExceptionsInNamespace()
 		$this->assertNoSniffErrorInFile($report);
 	}
 
+	public function testThrowExceptionForUndefinedKeyword()
+	{
+		$report = $this->checkFile(
+			__DIR__ . '/data/unknownKeyword.php',
+			['fullyQualifiedKeywords' => ['T_FOO']]
+		);
+
+		$this->assertSame(1, $report->getErrorCount());
+		$this->assertSame('unknownSniff', $report->getErrors()[1][1][0]['source']);
+		$this->assertContains('Value for keyword token not found, constant "T_FOO" is not defined', $report->getErrors()[1][1][0]['message']);
+	}
+
 
 	public function testFixableReferenceViaFullyQualifiedName()
 	{

tests/Sniffs/Namespaces/data/unknownKeyword.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace Foo;
+
+class Foo implements \Baz, \Foo\Baz
+{
+
+}