How to write a function that deletes user from Firestore and file from Storage?

In my app, I allow my users revoke their access. So when a user is deleted from the Firebase Authentication, I have a function that deletes the user from Firestore:

const functions = require("firebase-functions");
const admin = require("firebase-admin");
admin.initializeApp();

exports.deleteUser = functions.auth.user().onDelete((user) => {
  const uid = user.uid;

  return admin
      .firestore()
      .collection("users")
      .doc(uid)
      .delete();
});

Which works fine. The problem is that I want to delete the profile picture that is stored in Firebase Storage at: images/uid.png as well. So how to delete the document in Firestore together with the image in Storage, only if the image exists? Thanks in advance.

>Solution :

You can use the Admin SDK for Cloud Storage (API documentation) as follows:

exports.deleteUser = functions.auth.user().onDelete(async (user) => {

    try {
        const uid = user.uid;

        await admin
            .firestore()
            .collection("users")
            .doc(uid)
            .delete();

        const file = admin.storage().bucket().file(`images/${uid}.png`);
        const fileExists = await file.exists();
        if (fileExists) {
            await file.delete();    
        }
        
        return true;
        
    } catch (error) {
        console.log(error);
        return true;
    }
});

Note that you could also use the Delete User Data extension which is exactly done for this case: "Deletes data keyed on a userId from Cloud Firestore, Realtime Database, or Cloud Storage when a user deletes their account. "