code: function rewriteWhitespaceRanges(path) {
    const {node} = path;
  
    let spacePath = null;
    let tPath = null;
    let nPath = null;
    let rPath = null;
    let fPath = null;
  
    node.expressions.forEach((expression, i) => {
  
      // Space
      if (isChar(expression, ' ')) {
        spacePath = path.getChild(i);
      }
  
      // \t
      else if (isMetaChar(expression, '\\t')) {
        tPath = path.getChild(i);
      }
  
      // \n
      else if (isMetaChar(expression, '\\n')) {
        nPath = path.getChild(i);
      }
  
      // \r
      else if (isMetaChar(expression, '\\r')) {
        rPath = path.getChild(i);
      }
  
      // \f
      else if (isMetaChar(expression, '\\f')) {
        fPath = path.getChild(i);
      }
  
    });
  
    // If we found the whole pattern, replace it.
    // Make \f optional.
    if (
      spacePath &&
      tPath &&
      nPath &&
      rPath
    ) {
  
      // Put \s in place of \n.
      nPath.node.value = '\\s';
  
      // Other paths are removed.
      spacePath.remove();
      tPath.remove();
      rPath.remove();
  
      if (fPath) {
        fPath.remove();
      }
    }
  }
docs: Rewrites whitespace ranges: [ \t\r\n\f] -> \s.