Improve type definitions for sizeof (#41517)

types/sizeof/index.d.ts

@@ -3,5 +3,6 @@
 // Definitions by: Daniel Perez Alvarez <https://github.com/unindented>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 
-export function sizeof(object: object, pretty?: boolean): number | string;
+export function sizeof(object: any, pretty?: false): number;
+export function sizeof(object: any, pretty: true): string;
 export function format(bytes: number): string;

types/sizeof/sizeof-tests.ts

@@ -8,6 +8,7 @@ const anyObject = {
   },
 };
 
-console.log(sizeof(anyObject)); // 50
+console.log(sizeof(anyObject) + 0); // 50
+console.log(sizeof(anyObject, false) + 0); // 50
 console.log(sizeof(anyObject, true)); // 50B
 console.log(format(50)); // 50B