function getLastRow(sheet) { var output = { state: "init", debug: {sheet}, error: "" }; try { var last_row = -1; var row_scan = 99999; for (let i = 1; i < row_scan; i++) { if (checkLastRow(sheet, i)) { // print last row number last_row = i - 1; output = { ...output, debug: { ...output.debug, last_row } }; console.log("last row is " + last_row.toString()); break; } else { // keep going } } if (last_row == -1) { throw new Error('cannot find the last row') } return last_row; } catch (error) { console.log('getLastRow error') output = { ...output, error }; console.log(output); } }