How to add composite unique condition

[felstormrage]

How can I add a composite unique condition on two fields (author, slug)

{
  name: 'slug',
  type: 'text',
},
{
  name: 'author',
  type: 'relationship',
  relationTo: 'creators',
},

[JarrodMFlesch]

@rednithin you could make a third field that concatenates these two (with a hook), and mark that field as unique.