Copy last row on change - simultaneous entries - google-apps-script

Question

I have a google script that copies the last row on that spreadsheet to another spreadsheet sheet every time an entry is made. This entry is not linked to a Google form at all - so it is not bound to an onFormSubmit trigger - this submission is made from a JotForm form and inserted into the spreadsheet automatically. What I would like to know if my code will always work even if say two users make their submissions at the same time.
The code works fine - there seems to be no problem with that. I use the On change trigger. But I'd like to make sure it would always work. Many thanks for your help in advance.
function copyLastRow() {
var target = SpreadsheetApp.openById('xxxxx').getSheetByName('Records');
var sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName('Sheet1');
var lastrow = sheet.getLastRow();
var sourceData = sheet.getRange(lastrow, 1, 1, 10).getValues();
target.appendRow(sourceData[0]);
}

Answer 1

This is kind of the template I imagine you could use in completing this objective.
function updateSpreadsheet() {
//Open Form Responses Spreadsheet and get the Sheet you are reading data from
// You will need to update ID and SheetName parameters for your own sheets.
var formResponses = SpreadsheetApp.openById(ID).getSheetByName(SheetName);
//Open destinationSheet that you are writing to and get the sheet that you are writing to
// You will need to update ID and SheetName parameters for your own sheets.
var destinationSheet = SpreadsheetApp.openById(ID).getSheetByName(SheetName);
//Getting last rows from formResponse and destinationSheet
//It is not totally necessary to create everything as a variable, but I wanted to make it explicit what I am doing here
var formResponsesLastRow = formResponses.getLastRow();
var destinationSheetLastRow = destinationSheet.getLastRow();
//We are going to calculate the difference between the formResponse and destinationSheet
//This lets us know how many more rows have been added since we last updated destinationSheet
var numberNewRows = formResponsesLastRow - destinationSheetLastRow;
//Now get the new data to Write
var dataToWrite = formResponses.getRange((formResponsesLastRow - numberNewRows) + 1 , 1, numberNewRows, 3).getValues();
//Write to destinationSheet
destinationSheet.getRange(destinationSheetLastRow + 1, 1, numberNewRows, 3).setValues(dataToWrite);
}