[TypeScript]: Typing a class on the `globalThis` variable-CodePudding

I am trying to add type definitions to variable on globalThis that should act as a class. In JavaScript:

globalThis.X = class {
  ...
}

I am having trouble adding the type definitions on the globalThis object to allow this to work.

declare global {
  module globalThis {
    // Doesn't work. TypeScript error in declaration file.
    var X = (class {
      ...
    })

    // Doesn't work. TypeScript error on usage.
    class X {
      ...
    }
  }
}

const x = new globalThis.X();

console.log(x.value); // This works and will return the actual value on x.

See codesandbox for example reproduction.

CodePudding user response：

In TypeScript, by adding new before the function definition it will act as a constructor. In your example:

declare global {
  module globalThis {
    interface XType {
      value: number;
    }
    var X: new (x?: number, y?: number) => XType;
  }
}

Then when you try to use new globalThis.X(), you should get a type safe variable as the output of type XType.