func listen()

in FriendlyEats/LocalCollection.swift [56:75]

• 19 lines of code
• 2 McCabe index (conditional complexity)

  func listen() {
    guard listener == nil else { return }
    listener = query.addSnapshotListener { [unowned self] querySnapshot, error in
      guard let snapshot = querySnapshot else {
        print("Error fetching snapshot results: \(error!)")
        return
      }
      let models = snapshot.documents.map { (document) -> T in
        if let model = T(dictionary: document.data()) {
          return model
        } else {
          // handle error
          fatalError("Unable to initialize type \(T.self) with dictionary \(document.data())")
        }
      }
      self.items = models
      self.documents = snapshot.documents
      self.updateHandler(snapshot.documentChanges)
    }
  }