I have a component, with the following function inside of it:

const RolloutPage = () => {

    const getServiceHistory = async (serviceName, account) => {

    };
}
export default withRouter(RolloutPage);

How can i mock the inside function? I have tried:

jest.spyOn(<RolloutPage/>, 'getServiceHistory').mockImplementation(() =>
        Promise.resolve({
            json: () => Promise.resolve({ serviceTimelineDataMock }),
        })
    );
    render(
    <MemoryRouter>
        <PageErrorBoundary>
            <RolloutPage />
        </PageErrorBoundary>
    </MemoryRouter>
    )

But it gives me the following error:

Cannot spy the getServiceHistory property because it is not a function; undefined given instead

I have tried some of the other answers here in SO, but none of them worked.