Type Alias GlobalThis

Declare locally scoped properties on globalThis.

When defining a global variable in a declaration file is inappropriate, it can be helpful to define a type or interface (say ExtraGlobals) with the global variable and then cast globalThis via code like globalThis as unknown as ExtraGlobals.

Instead of casting through unknown, you can update your type or interface to extend GlobalThis and then directly cast globalThis.

import type {GlobalThis} from 'type-fest';

type ExtraGlobals = GlobalThis & {
	readonly GLOBAL_TOKEN: string;
};

(globalThis as ExtraGlobals).GLOBAL_TOKEN;
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