Jest does not support source-maps, TypeScript does not retain lines. Using
ts-jest or our own solution does not hit Jest's file cache and everything
slows to a crawl.
Mixing TS and JS React components does not work as (I) expected. See
import-component/ example.
Redux requires a lot of boilerplate (switch statement + types) to make it type safe.
(Useful tricks: https://github.com/piotrwitek/react-redux-typescript-patterns)