firebase - How to get a Firestore document size?

Question

From Firestore docs, we get that the maximum size for a Firestore document is:

Maximum size for a document 1 MiB (1,048,576 bytes)

QUESTION

How can I know the current size of a single doc, to check if I'm approaching that 1mb limit?

Example:

var docRef = db.collection("cities").doc("SF");

docRef.get().then(function(doc) {
    if (doc.exists) {
        console.log("Document data:", doc.data());
        // IS THERE A PROPERTY THAT CAN DISPLAY THE DOCUMENT FILE SIZE?
    } else {
        // doc.data() will be undefined in this case
        console.log("No such document!");
    }
}).catch(function(error) {
    console.log("Error getting document:", error);
});

Answer 1

Waitting for answers