Cannot add new country to CountryMap chart

I was trying add new country following to https://superset.apache.org/visualization.html#need-to-add-a-new-country, however it doesn’t work - new country is visable in dropdown, but when I click on it, map is blank.

Expected results

Can display new added map from .geojson

Actual results

I get 404 when I click new country on dropdown map is fetching:

Request URL: http://localhost:5000/superset/explore/undefined
Status Code: 404 NOT FOUND

Other (default) maps works properly:

Request URL: http://localhost:5000/static/assets/dist/5f64d14062abb5f5fd6610972976ebe6.geojson
Status Code: 200 OK

I was able to resolve this issue by editing assets/node_modules/@superset-ui/legacy-plugin-chart-country-map/countries.js and add .geojson file to this directory. So it means that maps are fetched from npm package?

How to reproduce the bug

https://superset.apache.org/visualization.html#need-to-add-a-new-country

Environment

• superset version: 0.999.0dev
• python version: Python 3.7.5
• node.js version: v12.12.0
• npm version: 6.11.3

I built superset from source.

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[czue]

I just submitted a PR to update the docs for this: https://github.com/apache/incubator-superset/pull/10621 based on this comment and successfully going through the process. Hopefully it will be merged and save others the trouble that I’ve had to go through to get this working!