JSON to Gherkins

var sourceArr = [
    {
        "article_id": 71942,
        "event_code": "A9",
        "start_date": "2016-11-25",
        "end_date": "2016-12-30",
        "quantity_alloted": 120,
        "first_delivery_date": "2016-11-25",
        "year": 2016,
        "delivery_schedules": [
            {
                "delivery_date": "2016-11-26",
                "quantity": 60
            },
            {
                "delivery_date": "2016-12-02",
                "quantity": 40
            },
            {
                "delivery_date": "2016-12-05",
                "quantity": 20
            }
        ]
    },
    {
        "article_id": 71943,
        "event_code": "A9",
        "start_date": "2016-11-25",
        "end_date": "2016-12-30",
        "quantity_alloted": 20,
        "first_delivery_date": "2016-11-25",
        "year": 2016,
        "delivery_schedules": [
            {
                "delivery_date": "2016-11-25",
                "quantity": 20
            }
        ]
    }
];

function jsonToGherkan(jsonArr) {
    var returnArr = []
	var headerArray = [];
	Object.keys(jsonArr[0]).forEach(function(header) {	
		if(!Array.isArray(jsonArr[0][header])){
			headerArray.push(header)
		}
	});

	var headerRow = " | id | " + headerArray.join(" | ") + " | "; 
	returnArr.push(headerRow);
	for (var i = 0; i < jsonArr.length; i++) {
	    var rowArr = [ i + 1 ];
	    for( var j = 0 ; j < headerArray.length; j++ ){
	        var cell = jsonArr[i][headerArray[j]];
	        if(Array.isArray(cell)) {
               returnArr.push(jsonToGherkan(cell));
	        } else {
	        	rowArr.push(cell);
	        }
	    }
	    var contentRow = " | " + rowArr.join(" | ") + " | "; 
	    returnArr.push(contentRow);
	}
	return returnArr;
}

console.log(jsonToGherkan(sourceArr).join("\n"));
for(var i = 0; i < sourceArr.length; i++) {
	console.log(jsonToGherkan(sourceArr[i].delivery_schedules).join("\n"));
}