Closed
Description
Suppose you have an onWrite cloud function trigger on a specific path such as /attributes/count.
exports.count = functions.database.ref('/attributes/count')
.onWrite(async (change, context) => {
console.log("before data >>>> " + change.before.exists());
console.log("after data >>>> " + change.after.exists());
console.log("before data value >>>> " + change.before.val());
console.log("after data value >>>> " + change.after.val());
return null;
});
Set a value of 0 to that path /attributes/count.
See the output of the above function.
before data >>>> false
after data >>>> false
before data value >>>> null
after data value >>>> 0
You can see that the after-data value is 0 but change.after.exists() returns false.
Now try to get the value at path /attributes/count.
const snap = await admin.database().child('attributes').child('count').once('value');
console.log(snap.exists()); // this will give you true for value 0.
So only change.before.exists() or change.after.exists() is returning false for value 0.
As per my testing, working fine on firebase-functions: ^3.21.2 but when I updated to firebase-functions: ^4.1.0, it gave the issue.
Using Node 16
"engines": {
"node": "16"
}