This can be simplified and readability improved:

```js
searchAndLinkEmail: function lh_searchAndLinkEmail(body) {
  return body.replace(this._emailRegex,
     function lh_processedEmail(email) {
      return [
        '<a href="#" data-email="', 
        '" data-action="email-link">',
        '</a>'
      ].join(email);
   });
 },
```