firebase firestore rules authenticated access to all collections except one

Question

I have the following firestore structure, basically 3 collections

publicdata protecteddata1 protecteddata2

I want to have protecteddata1 and protecteddata 2, and really the entire firestore database as authenticated users only. But i want the public to have readonly access to 'publicdata' collection..

The following is my attempt but it doesn't work

rules_version = '2';
service cloud.firestore {
  match /databases/{database}/documents {
    match /{document=**} {
      allow read;
      allow write: if (request.auth.uid != null);
    }
    match /publicdata {
       allow read;
    }
  }
}

Answer 1

You can use the following functions I created to do this

function isUserAuthenticated() {
    return request.auth.uid != null; 
}

You can then use it like this:

rules_version = '2';
service cloud.firestore {
  match /databases/{database}/documents {
    match /{document=**} {
      allow read, write: if isUserAuthenticated();
    }
    
    match /publicdata/{itemId} {
      allow read : if true;
      allow create : if isUserAuthenticated();
      allow update: if isUserAuthenticated();
      allow delete: if isUserAuthenticated();
    }

    /* Functions */
    function isUserAuthenticated() {
      return request.auth.uid != null; 
    }
  }
}