JSFiddle - React, Tailwind, and code Playground

HTML

<div ng-app="MergeDemo">

  <div ng-controller="MergeCtrl">
    
    <pre>{{merged}}</pre>
  
  </div>

</div>

JavaScript

var app = angular.module("MergeDemo", []);

app.controller("MergeCtrl", function($scope) {
	$scope.part2 = {
    labels: [ 'Jan', 'Feb', 'Jul','Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'],
    datasets: [
        {
            label: 'My Second dataset',
            fillColor: 'rgba(151,187,205,0.2)',
            strokeColor: 'rgba(151,187,205,1)',
            pointColor: 'rgba(151,187,205,1)',
            pointStrokeColor: '#fff',
            pointHighlightFill: '#fff',
            pointHighlightStroke: 'rgba(151,187,205,1)',
            data: [ 102, 123, 145, 60, 161]
        }
    	]
    }
    
  $scope.part1 = {
    labels: ['Jan', 'Feb', 'Jul'],
    datasets: [
      {
        label: 'My First dataset',
        fillColor: 'rgba(220,220,220,0.2)',
        strokeColor: 'rgba(220,220,220,1)',
        pointColor: 'rgba(220,220,220,1)',
        pointStrokeColor: '#fff',
        pointHighlightFill: '#fff',
        pointHighlightStroke: 'rgba(220,220,220,1)',
        data: [75, 59, 80, 81, 56, 55]
      }
    ]
  };
  
  $scope.combineParts = function(part1, part2) {
  	var merged = angular.copy( part1 );
    
    for ( key in part1 )
    {    
    	if ( part2.hasOwnProperty(key) )
      	merged[key].push.apply(merged[key], part2[key])
    }
    
    return merged;
  }
  
  $scope.merged = JSON.stringify($scope.combineParts($scope.part1, $scope.part2), null, "  ");
})