index.js

var geojsonCoords = require('@mapbox/geojson-coords'),
    traverse = require('neotraverse/legacy'),
    extent = require('@mapbox/extent');

var geojsonTypesByDataAttributes = {
    features: ['FeatureCollection'],
    coordinates: ['Point', 'MultiPoint', 'LineString', 'MultiLineString', 'Polygon', 'MultiPolygon'],
    geometry: ['Feature'],
    geometries: ['GeometryCollection']
}

var dataAttributes = Object.keys(geojsonTypesByDataAttributes);

module.exports = function(_) {
    return getExtent(_).bbox();
};

module.exports.polygon = function(_) {
    return getExtent(_).polygon();
};

module.exports.bboxify = function(_) {
    return traverse(_).map(function(value) {
        if (!value) return ;

        var isValid = dataAttributes.some(function(attribute){
            if(value[attribute]) {
                return geojsonTypesByDataAttributes[attribute].indexOf(value.type) !== -1;
            }
            return false;
        });

        if(isValid){
            value.bbox = getExtent(value).bbox();
            this.update(value);
        }

    });
};

function getExtent(_) {
    var ext = extent(),
        coords = geojsonCoords(_);
    for (var i = 0; i < coords.length; i++) ext.include(coords[i]);
    return ext;
}