mapboxgl.GeoJSONSource is not a constructor

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I want to move a marker in particular direction and got this error. Source Below mentioned.

body { margin:0; padding:0; }
#map { position:absolute; top:0; bottom:0; width:100%; }

mapboxgl.accessToken = 'ApiKey';
var map = new mapboxgl.Map({
container: 'map',
style: 'mapbox://styles/mapbox/satellite-hybrid-v8',
center: [-86.155231, 39.768458],
zoom: 6
});

var direction = 0, manual = false, speed = 0.1;

// create a GeoJSON point to serve as a starting point
var point = {
"type": "Point",
"coordinates": [-86.155231, 39.768458]
};

// add the GeoJSON above to a new vector tile source
var source = new mapboxgl.GeoJSONSource({
data: point
});

function setPosition() {
point.coordinates[0] += speed * Math.sin(direction) / 100;
point.coordinates[1] += speed * Math.cos(direction) / 100;
source.setData(point);

map.setLayoutProperty('drone', 'icon', direction * (180 / Math.PI));

if (!manual && Math.random() > 0.95) {
direction += (Math.random() - 0.5) / 2;
}

map.setCenter(point.coordinates);
}

map.on('style.load', function () {
map.addSource('drone', source);

map.addLayer({
"id": "drone-glow-strong",
"type": "circle",
"source": "drone",
"paint": {
"circle-radius": 18,
"circle-color": "#00e673",
"circle-opacity": .8
}
});

map.addLayer({
"id": "drone-glow",
"type": "circle",
"source": "drone",
"paint": {
"circle-radius": 40,
"circle-color": "#99ffcc",
"circle-opacity": 0.4
}
});

// Full icon list: https://www.mapbox.com/maki
map.addLayer({
"id": "drone",
"type": "symbol",
"source": "drone",
"layout": {
"icon-image": "car-24", // try: 'car-24', 'airport-24', 'zoo-24'
}
});

window.setInterval(setPosition, 10);
});

// Add manual control of the airplane with left and right arrow keys, just because
document.body.addEventListener('keydown', function (e) {
if (e.which == 37) { // left
direction -= 0.1;
manual = true;
}
if (e.which == 39) { // right
direction += 0.1;
manual = true;
}
if (e.which == 38) { // faster
speed = Math.min(speed + 0.1, 10);
manual = true;
e.preventDefault();
}
if (e.which == 40) { // slower
speed = Math.max(speed - 0.1, 0);
manual = true;
e.preventDefault();
}
}, true);

Start with the inline HTML example and the mapbox-gl-js v0.12.0 script reference, then inspect the `new mapboxgl.GeoJSONSource` call and the later `map.addSource('drone', source)` entry point. Determine the supported way to provide the GeoJSON source and verify that the marker example no longer raises the constructor error.

Written by the indexing model from the issue text.