Firebase function: manipulate admin.database.ServerValue.TIMESTAMP

Question

I want to automatically create an expiration timestamp for new items that are added to the Firebase database. So I wrote the following function:

exports.onCreateNewItem = functions.database.ref('/items/{item_id}').onCreate(event => {
    var mergedUpdate = {};
    mergedUpdate['expiration'] = admin.database.ServerValue.TIMESTAMP + 2678400000;
    return event.data.adminRef.update(mergedUpdate);
})

However, it doesn't work. The value in /items/{item_id}/expiration is "[object Object]2678400000" while I expected it to be the timestamp of 31 days from now.

Answer 1

Because your Cloud Function code runs on a Google server, you have access to the server time via Date.now() . You don't need to use admin.database.ServerValue.TIMESTAMP .

exports.onCreateNewItem = functions.database.ref('/items/{item_id}').onCreate(event => {
    var mergedUpdate = {};
    mergedUpdate['expiration'] = Date.now() + 2678400000;
    return event.data.adminRef.update(mergedUpdate);
})