TS2397

Declaration name conflicts with built-in global identifier 'globalThis'.

Broken Code ❌

declare module globalThis {
  var signin: () => string[];
}
 
this.signin();

Fixed Code ✔️

To merge your additions with the existing globalThis definition, you can use a namespace:

declare module 'global' {
  namespace globalThis {
    var signin: () => string[];
  }
}
 
this.signin();