JSFiddle - React, Tailwind, and code Playground

JavaScript

var array1 = [
	{name: "dima"}
];

var test = [];

var array2 = [
	{
  	name: "dima",
    age: 22,
    notes: "test0"
  },
  {
  	name: "oleg",
    age: 27,
    notes: "test1"
  },
  {
  	name: "vasja",
    age: 44,
    notes: "test2"
  }
];

array2.forEach(n => {
  var obj = array1.find(m => m.name === n.name)
  if (obj) {
    Object.assign(obj, n)
  } else {
    array1.push({ ...n })
  }
})

console.log(array1, "array1");