simply convert a spreadsheet to an array of Json

convertSheetToJson.js

function convertSheetToJson(sheet) {
  var titleRange = sheet.getRange(1, 1, 1, sheet.getLastColumn());
  var titles = titleRange.getValues()[0];

  var rowRange = sheet.getRange(2, 1, sheet.getLastRow(), sheet.getLastColumn());
  var rows = rowRange.getValues();
  
  // create json
  var result = [];
  for(var i = 0; i < rows.length; i++) {
    var row = rows[i];
    var json = {};
    
    for(var j = 0; j < titles.length; j++) {
      json[titles[j]] = row[j];
    }
    result.push(json);
  }
  return result;
}