Add unit tests.

tests/phpunit/tests/rest-api/rest-widget-types-controller.php

@@ -121,6 +121,17 @@ public function test_get_items() {
 		}
 	}
 
+	/**
+	 * @ticket 56481
+	 */
+	public function test_get_items_with_head_request_should_not_prepare_post_data() {
+		wp_set_current_user( self::$admin_id );
+		$request  = new WP_REST_Request( 'HEAD', '/wp/v2/widget-types' );
+		$response = rest_get_server()->dispatch( $request );
+		$this->assertSame( 200, $response->get_status(), 'The response status should be 200.' );
+		$this->assertNull( $response->get_data(), 'The server should not generate a body in response to a HEAD request.' );
+	}
+
 	/**
 	 * @ticket 53303
 	 */