firestore.rules

rules_version = '2';
service cloud.firestore {
  match /databases/{database}/documents {
    match /helloWorldUsers/{userId}/drafts/{draftId} {
      function ownsDraft() {
        return request.auth != null && request.auth.uid == userId;
      }
      function validDraft() {
        let data = request.resource.data;
        return data.keys().hasAll(['language', 'filename', 'code', 'updatedAt'])
          && data.keys().hasOnly(['language', 'filename', 'code', 'updatedAt'])
          && data.language is string && data.language.size() > 0 && data.language.size() <= 64
          && data.filename is string && data.filename.size() > 0 && data.filename.size() <= 128
          && data.code is string && data.code.size() <= 100000
          && data.updatedAt == request.time;
      }
      allow read, delete: if ownsDraft();
      allow create, update: if ownsDraft() && validDraft();
    }
    // Every other path is denied unless you add rules for another application.
  }
}