Chartjs v2 - format tooltip for multiple data sets (bar and line)

var ctx = document.getElementById("canvas").getContext("2d");
var myChart = new Chart(ctx, {
    type: 'bar',
    data: {
        labels: ["January", "February", "March", "April", "May"],
        datasets: [{
            type: 'line',
            label: "Sales",
            data: [144.36534, 146.42534, 145.23534, 147.19534, 145],
            fill: false,
            borderColor: '#EC932F',
            backgroundColor: '#EC932F',
            tension: 0,
            yAxisID: 'y-axis-2'
        }, {
            type: 'bar',
            label: "Visitor",
            data: [22345343, 23345343, 24345343, 25345343, 230245343],
            backgroundColor: '#71B37C',
            yAxisID: 'y-axis-1'
        }]
    },
    options: {
        responsive: false,
        tooltips: {
            mode: 'index',
            intersect: false,
            callbacks: {
                label: function (t, d) {
                    if (t.datasetIndex === 0) {
                        return '$' + t.yLabel.toFixed(2);
                    } else if (t.datasetIndex === 1) {
                        if (t.yLabel.toString().length === 9) {
                            return Math.round(+t.yLabel.toString().replace(/(\d{3})(.*)/, '$1.$2')) + 'M';
                        } else return Math.round(+t.yLabel.toString().replace(/(\d{2})(.*)/, '$1.$2')) + 'M';
                    }
                }
            }
        },
        scales: {
            yAxes: [{
                id: "y-axis-1",
                position: "left"
            }, {
                id: "y-axis-2",
                position: "right"
            }]
        }
    }
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.5.0/Chart.min.js"></script>
<canvas id="canvas" width="400" height="190"></canvas>