[ericelliott]

Some good reasons for that:

1. I get type feedback in my browser with inference. 2. I get near real-time feedback from TDD on file save. 3. I get real-time lint feedback, too.

The net result is I get several multiples better bug coverage than TypeScript alone can provide at about the same speed -- while writing idiomatic JS.

[ng12]

> TypeScript alone can provide at about the same speed

If writing your unit tests contributes less overhead than writing TypeScript types you're doing something horribly wrong.

[ericelliott]

It's not less overhead, but you can't skip TDD with TypeScript because at least 80% of bugs are not detectable by TypeScript.