jslint-xml.js

const xmlEscape = s => (`${s}`).replace(/[<>&"'\x00-\x1F\x7F\u0080-\uFFFF]/g, c => {
  switch (c) {
    case '<':
      return '&lt;';
    case '>':
      return '&gt;';
    case '&':
      return '&amp;';
    case '"':
      return '&quot;';
    case '\'':
      return '&apos;';
    default:
      return `&#${c.charCodeAt(0)};`;
  }
});

module.exports = results => {
  const files = results.map(file => {
    const warnings = file.warnings.map(({column, line, text}) => {
      const css = file._postcssResult && file._postcssResult.css;
      const lines = css && css.split('\n') || [];
      const evidence = lines[line - 1];

      return [
        `<issue line="${line}"`,
        ` char="${column}"`,
        ` evidence="${evidence ? xmlEscape(evidence) : ''}"`,
        ` reason="${xmlEscape(text)}" />`
      ].join('');
    });

    return `<file name="${file.source}">${warnings.join('')}</file>`;
  });

  return `<?xml version="1.0" encoding="utf-8"?><jslint>${files.join('')}</jslint>`;
};