gas.js

String.prototype.trimLeft  = function(){ return this.replace(/^\s+/,'') }
String.prototype.trimRight = function(){ return this.replace(/\s+$/,'') }
String.prototype.trim = function(){ return this.trimLeft().trimRight() }

function readSheet(){
  
  var dataFileId = ""; //TODO: add your data.txt file id
  var ssFileId = ""; //TODO: add your spreadsheet file id
  
  var content = DriveApp.getFileById(dataFileId).getAs('application/json').getDataAsString();
  //Logger.log(content);
  
  var data = JSON.parse(content);
  //Logger.log(data);
  
  var ss = SpreadsheetApp.openById(ssFileId);
  //SpreadsheetApp.flush();
  
  var sheet = ss.getActiveSheet();
  
  //Clear content if you open ss in edit mode.
  if (sheet.getLastRow() > 1 || sheet.getMaxColumns() > 1 ){ 
    sheet.getRange(1, 1, sheet.getLastRow(), sheet.getMaxColumns()).clear();
  }
  
  for (var i = 0; i < data.length; i++) {
    for (j = 0; j < data[i].length; j++) {
      var destinationRange = sheet.getRange(i+1, j+1, 1, 1);
      destinationRange.setValue(data[i][j].VALUE.trim());
      
      if (data[i][j].NUMBER !== undefined &amp;&amp; data[i][j].FORMAT !== undefined) {
        destinationRange.setNumberFormat(data[i][j].FORMAT.trim());
      }
      if (data[i][j].STYLE !== undefined &amp;&amp; data[i][j].STYLE.BACKGROUNDCOLOR !== undefined) {
        destinationRange.setBackground(data[i][j].STYLE.BACKGROUNDCOLOR.trim());
      }
      if (data[i][j].STYLE !== undefined &amp;&amp; data[i][j].STYLE.COLOR !== undefined) {
        destinationRange.setFontColor(data[i][j].STYLE.COLOR.trim());
      }
    }
  }
  
}