Firestore: how to get the document ID when listening to a collection?

Question

firebase

Hello!
Not quite sure how to solve the following problem, namely how to get the auto-generated document ID when listening to a collection? That is, we have the following code:

created() {
    // Get current user and get info from db
    let currentUser = firebase.auth().currentUser
    this.$store.dispatch('setUserId', currentUser.uid)

    let ref = db.collection('categories').where('user_id', '==', currentUser.uid).orderBy('category_name')
    ref.onSnapshot(snapshot => {
      // snapshot.forEach(doc => {
      //   тут у нас есть doc.id
      //   return this.$store.commit('addCategory', {category_name: doc.data().category_name, user_id: doc.data().user_id})
      // })

      snapshot.docChanges().forEach(change => {
        if (change.type == 'added') {
      //   тут какой-либо doc.id или change.id у нас нет
          let doc = change.doc
          return this.$store.commit('addCategory', {category_name: doc.data().category_name, user_id: doc.data().user_id})
        }
      })
    })
  }

The bottom line is that I keep track of the documents in the collection and when a new one appears, I add it to the vuex store. The problem is that using snapshot.docChanges() I can't get to the document ID. I would not really like to create my own, because why, if it is already there.
If we just use snapshot.forEach , then we have a document id parameter. That is, we can get the document ID through doc.id. There is no such thing for docChanges() . You can get to the ID in the parameters, but then the entry looks like "changes.doc._document.key.path.segments[6]" , which doesn't look very cool.
I want to get Id in order to make more correct queries in the database in the future, to delete / edit records. You can do without it, but I would like to figure out how to get it right.
Thank you very much for the answer!