vega = {
const Vega = await require('vega'),
projections = await require('d3-geo-projection', 'd3-geo-polygon');
for (let p in projections) {
let a = p.match(/^geo(.*)/);
if (a) {
let name = a[1][0].toLowerCase() + a[1].slice(1);
Vega.projection(name, projections[p]);
}
}
return function vega(spec) {
var div = document.createElement("div");
var view = new Vega.View(Vega.parse(spec));
return view.initialize(div).runAsync().then(function() { return div; });
};
}