Tree shaking does not work on dependencies of dependencies

Converting from ES6 named imports, such as

import {faTimes} from "@fortawesome/pro-light-svg-icons"
import {Range} from "rc-slider"

to specific (“cheery picking”) imports, such as

import {faTimes} from "@fortawesome/pro-light-svg-icons/faTimes"
import Range from "rc-slider/es/Range"

reduced bundle size from 1.01MB to 870kb. I know that this is what we should expect from Lodash, but that tree shaking is possible with named imports . Could it be that CRA, due to its Babel-Webpack configuration, blocks “tree shaking” for named imports?

Project details: “react-scripts”: “2.1.5”, Typescript

Resources: optimizing-js-tree-shaking-1, optimizing-js-tree-shaking-2

[simonssspirit]

We are also interested in this improvement.

You can change your own imports, but in cases with third party packages which use name imports internally, you have no option to change it.

[carpben]

@iansu, @ianschmitz, Do you mind sharing your opinion?