How to remove Source/Layer from Map?

[nonoumasy]

I'm trying to dynamically add GeoJson to the map. I can add each item using the and combo. However, once its added to the map, I can't seem to be able to remove it completely. It will remain semi-opaque.

I made a prototype here:
https://codesandbox.io/s/mapbox-with-geojson-egxb6?file=/src/components/MapComp.js

[Pessimistress]

You need to add key props to your Source components if you are arbitrarily adding and removing them in a list.