@nodecfdi/cfdi-cleaner/dist/esm/xml_string_cleaners/append_xml_declaration.js

Librería para limpiar comprobantes fiscales digitales v3.3 y v4.0

export default class AppendXmlDeclaration {
    clean(xml) {
        let xmlResult = xml;
        if (!xmlResult.startsWith('<?xml ')) {
            xmlResult = `<?xml version="1.0"?>\n${xmlResult}`;
        }
        return xmlResult;
    }
}