Firestore Cloud Functions priority

Question

Firestore Cloud Functions priority

Now I deploy two cloud functions in the Firestore database.

They are triggered by the same document changes.

Is it

Answer 1

There is no way to indicate relative priority between functions.

If you have a defined order you want them invoked in, use a single Cloud Function and just call two regular functions from there:

exports.onCommentWritten = functions.firestore
.document('post/{postId}/comments/{commentsID}')
.onWrite((change, context) => { 
  return Promise.all([
    updateCommentNum,
    writeUserLog
  ])
})

function updateCommentNum(change, context) {
    //update the comment numbers in the post/{postId}/
}

function writeUserLog(change, context) {
    //write the comment name,text,ID,timestamp etc. in the collection "commentlog"
}

That will also reduce the number of invocations, and thus reduce the cost of operating them.