Formula to edit a cell based on if-else condition - google-apps-script

Question

I am planning to create a cell where if the cells in G2 is empty then it will copy the content from row A but if the cell in column G is updated with something else I dont want to copy the content from row A. I have done code something like this in App Script but it is not working.
function getLast(range) {
var getResult = function(range) {
if (!((range.getNumRows() > 1 && range.getNumColumns() == 1) || (range.getNumRows() == 1 && range.getNumColumns() > 1))) {
throw new Error("Please input one row or one column.");
}
var v = Array.prototype.concat.apply([], range.getValues());
var f = Array.prototype.concat.apply([], range.getFormulas());
var i;
for (i = v.length - 1; i >= 0; i--) {
if (v[i] != "" || f[i] != "") break;
}
return i + 1;
};
if (Array.isArray(range)) {
return range.map(function(e) {
return getResult(e);
});
} else {
try {
range.getA1Notation();
} catch (e) {
throw new Error("Inputted value is not a range.");
}
return getResult(range);
}
}
function formulasheets(){
var ss = SpreadsheetApp.openByUrl(url);
var sheet = ss.getSheetByName("USERNAMES");
sheet.getRange("G2").setFormula('=IF(G2="",A2, ');
var range1 = sheet.getRange("B:B");
var fillDownRangecolumnI = sheet.getRange(2, 7, lr-1);
sheet.getRange("G2").copyTo(fillDownRangecolumnA);
}
I have attached the image of my google sheet to explain better on what I want. Can ayone help me on this. Thank you.
If Cell G2 & G5 is empty
It should be updated with content in row A

Answer 1

I see your question, and I would like to give a try, hope it is useful for you. Please refer to my edited code below, I think it is better for you to use for loop to check for blank, and to avoid write formula:
function formulasheets(){
var ss = SpreadsheetApp.openByUrl(url);
var sheet = ss.getSheetByName("USERNAMES");
for (var x=1;x <= sheet.getLastRow();x++){
var cell = sheet.getRange(x,7);
if (cell.isBlank()){
sheet.getRange(x,1).copyTo(cell);
}
}
}
Before execution
After execution, accept if help, it is my first time answer G Apps Script :)