TypeScript: Slow compilation time

Created by: td0m

Now that create-react-app now natively supports typescript, I gave it a try. I expected near instant compilation times after making a change to a file, just like with JavaScript. Instead, I got about 3-5s of delay on the official typescript cra (out of the box). I thought this delay would disappear after moving to babel 7, I thought we simply strip off TypeScript when running the dev server and properly compile TypeScript and check for errors when building the production build? Is this possible?