Google Sheets Apps Script to redact certain columns for rows older than 90 days (for use with Google Forms)

scrubEmailsAndNamesOfGamesStartedOver90DaysAgo.js

function scrubEmailsAndNamesOfGamesStartedOver90DaysAgo() {
  const sheetName = 'responses';
  
  
  const ss = SpreadsheetApp.getActiveSpreadsheet();
  const sheet = ss.getSheetByName(sheetName);
  if(!sheet) {
    throw new Error('failed to get sheet `' + sheetName + '`');
  }
  const data = sheet.getDataRange().getValues();
  
  const now = new Date();
  var sixMonthsAgo = new Date();
  sixMonthsAgo.setDate(now.getDate()-182);
  
  for (var rowNumber = 2; rowNumber < 1+data.length; rowNumber++) {     
    var dateString = getByName(data, 'date', rowNumber);
    
    if (dateString == '???' || dateString == '') {
      Logger.log('ignoring row ' + rowNumber + ' with date column `' + dateString + '`');
      continue;
    }
    var gamePlayedDate = new Date(dateString);
    
    // Logger.log('dateString: ' + dateString);
    // Logger.log('gamePlayedDate: ' + gamePlayedDate);  

    if(isNaN(gamePlayedDate)) {
      throw new Error('failed to parse date: `' +  dateString + '`');
    }
    
    Logger.log('checking row ' + rowNumber + ', played ' + gamePlayedDate);
    
    if (gamePlayedDate < sixMonthsAgo) {
      Logger.log('scrubbing row ' + rowNumber  + ': ' + dateString + ' is >90 days ago');
      setByName(sheet, data, 'name', rowNumber, 'DELETED');
      setByName(sheet, data, 'email', rowNumber, 'DELETED');
    }
  }
}

function getByName(data, colName, rowNumber) {
  const colIndex = data[0].indexOf(colName);
  if (colIndex == -1) {
    throw new Error('failed to get column called `' + colName + '`');
  }
  
  const rowIndex = rowNumber-1;
  return data[rowIndex][colIndex];
}

function setByName(sheet, data, colName, rowNumber, value) {  
  const colIndex = data[0].indexOf(colName); // colIndex is 0-indexed
  if (colIndex == -1) {
    throw new Error('failed to set column called `' + colName + '`');
  }
  
  const colNumber = colIndex + 1;
               
  sheet.getRange(rowNumber, colNumber).setValue(value);
}