Nested re-exports demo
module1.js and module2.js declare some simple functions which get grouped and re-exported in index.js. sample.js imports from the index and uses one export from one of the modules.
You should see in the prettified bundle that the module that goes completely unused is tree-shaken out, but all exports from the partially used module are included.
It sounds like export * as Name from "path" will eventually become a thing but it's not there yet. So this sample really just demonstrates that the grouped, nested re-exports essentially makes tree-shaking impossible within the sub-modules.