jscodeshift add type attribute to jsx buttons

gistfile1.js

module.exports = function(fi, api) {
  var j = api.jscodeshift;

  const hasNoTypeAttribute = function(path) {
    return !path.value.openingElement.attributes.some(function(typePath) {
      if (typePath.name.name !== 'type') {
        return false;
      }
      return true;
    });
  };

  const unshiftTypeAttribute = function(path) {
    const type = j.jsxAttribute(j.jsxIdentifier('type'), j.literal('button'));
    path.value.openingElement.attributes.unshift(type);
  };

  var out = j(fi.source)
      .findJSXElements('button')
      .filter(hasNoTypeAttribute)
      .forEach(unshiftTypeAttribute)
      .toSource();

  return out;
}