Ensure names are not empty

lib/PhpParser/Node/Name.php

@@ -218,8 +218,16 @@ class Name extends NodeAbstract
      */
     private static function prepareName($name) : array {
         if (\is_string($name)) {
+            if ('' === $name) {
+                throw new \InvalidArgumentException('Name cannot be empty');
+            }
+
             return explode('\\', $name);
         } elseif (\is_array($name)) {
+            if (empty($name)) {
+                throw new \InvalidArgumentException('Name cannot be empty');
+            }
+
             return $name;
         } elseif ($name instanceof self) {
             return $name->parts;

test/PhpParser/Node/NameTest.php

@@ -132,13 +132,29 @@ class NameTest extends TestCase
     }
 
     /**
-     * @expectedException        \InvalidArgumentException
+     * @expectedException \InvalidArgumentException
      * @expectedExceptionMessage Expected string, array of parts or Name instance
      */
     public function testInvalidArg() {
         Name::concat('foo', new \stdClass);
     }
 
+    /**
+     * @expectedException \InvalidArgumentException
+     * @expectedExceptionMessage Name cannot be empty
+     */
+    public function testInvalidEmptyString() {
+        new Name('');
+    }
+
+    /**
+     * @expectedException \InvalidArgumentException
+     * @expectedExceptionMessage Name cannot be empty
+     */
+    public function testInvalidEmptyArray() {
+        new Name([]);
+    }
+
     /** @dataProvider provideTestIsSpecialClassName */
     public function testIsSpecialClassName($name, $expected) {
         $name = new Name($name);