Detects the value of an option at the tree node.

@param {node} ast
function(ast) {
    let detected = [];

    ast.traverseByType('delimiter', function(delimiter, i, parent) {
      if (parent.is('arguments')) return;

      var nextNode = parent.get(i + 1);

      if (nextNode && nextNode.is('space')) {
        detected.push(nextNode.content);
      } else if (nextNode.first() && nextNode.first().is('space')) {
        detected.push(nextNode.first().content);
      } else {
        detected.push('');
      }
    });

    return detected;
  }