Function parse_string_rowan 

pub fn parse_string_rowan(source: &str) -> (SyntaxNode, Vec<SyntaxError>)

Parse a source string into a rowan lossless concrete syntax tree.

Returns the root SyntaxNode and any parse errors encountered.

use nginx_lint_parser::parse_string_rowan;

let (root, errors) = parse_string_rowan("listen 80;");
assert!(errors.is_empty());
assert_eq!(root.text().to_string(), "listen 80;");