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

If you need to extend the window object with a custom type that requires the use of import you can use the following method:

window.d.ts

import MyInterface from './MyInterface';

declare global {
    interface Window {
        propName: MyInterface
    }
}

See 'Global Augmentation' in the 'Declaration Merging' section of the Handbook: https://www.typescriptlang.org/docs/handbook/declaration-merging.html#global-augmentation