How do you explicitly set a new property on `window` in TypeScript?

Question

I setup global namespaces for my objects by explicitly setting a property on window.

window.MyNamespace = window.MyNamespace || {};

Answer 1

AS OF TYPESCRIPT ^3.4.3 THIS SOLUTION NO LONGER WORKS

Or...

you can just type:

window['MyNamespace']

and you wont get a compile error and it works the same as typing window.MyNamespace