mock mockReturnValue doesn't work

[Gennady77]

I use last version of React and try to write test in Jest:

const getItemSpy = jest.spyOn(localStorage, 'getItem');
getItemSpy.mockReturnValue(null);

and got error:
TypeError: getItemSpy.mockReturnValue is not a function

If I run:
console.log(getItemSpy.mockReturnValue);

It shows undefined

What's the problem?

[Smrtnyk]

This has nothing to do with swc, its jest issue
you need to spy on LocalStorage.prototype

[Smrtnyk]

also mockReturnvalue is a setter, not sure if that will return anything