I'm working through the Hackernews Express tutorial. In the section on Subscriptions the code snippet shows:

subscription {
  newLink {
    node { 
      ...
    }
  }
}

Seems this should be:

subscription {
  newLink {
    ...
  }
}

https://www.howtographql.com/graphql-js/7-subscriptions/

Indeed, can you report this here: https://github.com/howtographql/howtographql