Проверьте уникальный объект в Array Javascript Sate: Stackoverflow.com

var data = [
{name:"Joe", date:'2018-07-01', amt:250 },
{name:"Mars", date:'2018-07-01', amt:250 },
{name:"Joe", date:'2018-07-02', amt:250 },
{name:"Saturn", date:'2018-07-01', amt:250 },
{name:"Joe", date:'2018-07-02', amt:250 },
{name:"Jupiter", date:'2018-07-01', amt:250 },
]
var resArr = [];
data.filter(function(item){
  var i = resArr.findIndex(x => (x.name == item.name && x.date == item.date && x.amt == item.amt));
  if(i <= -1){
        resArr.push(item);
  }
  return null;
});
console.log(resArr)
Rich Ray