Am I having a local Firestore database? - node.js

Question

I want to understand what kind of Firestore database is installed to my box.
The code is running with node.js 9.
If I remove the internet for X minutes and put it back, I can see all the cached transactions going to Firestore (add, updates, deletes).
If I add firebase.firestore().enablePersistence() line after 'firebase.initializeApp(fbconfig), I am getting this error:
Error enabling offline persistence. Falling back to persistence
disabled: FirebaseError: [code=unimplemented]: This platform is either
missing IndexedDB or is known to have an incomplete implementation.
Offline persistence has been disabled.
Now, my question is. If I don't have persistence enabled or can't have it, how come when disconnecting my device from internet, I still have internal transaction going on? Am I really seeing it the proper way?
To me, beside not seeing the console.log() that I have inside the "then()" to batch.commit or transaction.update right away (only when putting back the internet) tells me that I have some kind of internal database persistence, don't you think?
Thanks in advance for your help.
UPDATE
When sendUpdate is called, it looks like the batch.commit is executed because I can see something going on in listenMyDocs(), but the console.log "Commit successfully!" is not shown until the internet comes back
function sendUpdate(response) {
const db = firebase.firestore();
let batch = db.batch();
let ref = db.collection('my-collection')
.doc('my-doc')
.collection('my-doc-collection')
.doc('my-new-doc');
batch.update(ref, { "variable": response.state });
batch.commit().then(() => {
console.log("Commit successfully!");
}).catch((error) => {
console.error("Commit error: ", error);
});
}
function listenMyDocs() {
const firebase = connector.getFirebase()
const db = firebase.firestore()
.collection('my-collection')
.doc('my-doc')
.collection('my-doc-collection');
const query = db.where('var1', '==', "true")
.where('var2', '==', false);
query.onSnapshot(snapshot => {
snapshot.docChanges().forEach(change => {
if (change.type === 'added') {
console.log('ADDED');
}
if (change.type === 'modified') {
console.log('MODIFIED');
}
if (change.type === 'removed') {
console.log('DELETED');
}
});
});

Answer 1

the console.log "Commit successfully!" is not shown until the internet comes back
This is the expected behavior. Completion listeners fire once the data is committed on the server.
Local events may fire before completion, in an effort to allow your UI to update optimistically. If the server changes the behavior that the client raised events for (for example: if the server rejects a write), the client will fire reconciliatory events (so if an add was rejected, it will firebase a change.type = 'removed event once that is detected).
I am not entirely sure if this applies to batch updates though, and it might be tricky to test that from a Node.js script as those usually bypass the security rules.