Display properties of nested GeoJson in Mapbox - nested

Question

I am unable to query nested properties feature, which is imported from a geojson source and displayed on a mapbox map.
I am able to get the feature with an on click listener, but as soon as the property is nested, the object is represented as a string
{
...
properties: {
address: "{"place":"Bern","street":"Fischerweg","street_nr":"11","zip":"3012"}"
price: 4500
}
}
Therefore I am only able to display the not-nested properties in a popup, when it is clicked.
my code:
const features = this.queryRenderedFeatures(e.point, {
layers: ['unclustered-point']
});
console.log(feature.properties.price) --> 4500
console.log(feature.properties.address) --> string instead of object {"place":"Bern","street":"Fischerweg","street_nr":"11","zip":"3012"}
console.log(feature.properties.address.street) --> undefined (--> NOT WORKING because of nested property)
const popup = new mapboxgl.Popup({offset: [0, -15]})
.setLngLat(feature.geometry.coordinates)
.setHTML('<h3>Price: ' + feature.properties.price + '</h3>
<p>Street: ' + feature.properties.address.street + '</p>')--> NOT WORKING because of nested property
.setLngLat(feature.geometry.coordinates)
.addTo(map);
I read that you can access nested properties with expressions, but how can expressions be applied in the html of the popup?
Is there a way how I can access the nested properties or do I have to redesign the geojson's structure?
any help is highly appreciated! Thank you so much,
Regards Simon

Answer 1

Since the property values are converted into JSON strings, you need a reverse conversion:
Object.keys(feature.properties).forEach(function(key) {
feature.properties[key] = JSON.parse(feature.properties[key]);
});
[ https://jsfiddle.net/s1d7hL82/ ]