Zoom to Feature in MapBox Map

zoomtofeat.js

var zoomToFeat = function(feature, map) {
        // based on this: https://www.mapbox.com/mapbox-gl-js/example/zoomto-linestring/
  
        // Geographic coordinates of the LineString
        var coordinates = feature.geometry.coordinates;

        // Pass the first coordinates in the LineString to `lngLatBounds` &
        // wrap each coordinate pair in `extend` to include them in the bounds
        // result. A variation of this technique could be applied to zooming
        // to the bounds of multiple Points or Polygon geomteries - it just
        // requires wrapping all the coordinates with the extend method.
        var bounds = coordinates.reduce(function(bounds, coord) {
            return bounds.extend(coord);
        }, new mapboxgl.LngLatBounds(coordinates[0], coordinates[0]));

        map.fitBounds(bounds, {
            padding: 20
        });
    };

Awesome, thanks @cwhite92!