I have the vite mock file as per the docs, but for my use case I could not work it out how to use it properly in a test:

Simple Store – note there’s middlewares

export const useStore = create<Store>()(
  devtools(
    subscribeWithSelector((set) => ({
      currentPage: 1,
      error: null,
      isLoading: false,
      photos: [],
      searchTerm: '',
      setIsLoading: (isLoading) => set({ isLoading }),
      setPhotos: (photos) => set({ photos }),
      setSearchTerm: (searchTerm) => set({ searchTerm }),
      setError: (error) => set({ error }),
    }))
  )
);

Simple example – but using the real store

test('renders when loading', () => {
  useStore.setState({ isLoading: true }); // I'm wanting to substitute this for the mock store...
  const component = render(<ImageGrid />);
  expect(component.asFragment()).toMatchInlineSnapshot(`...`);
});

// ... because next tests will be contaminated because the state is not reset

Doing it this way will will not use the storeResetFns that’s defined in the mock.

How do I use the create function to create a mock store so I an easily set states for testing?

References:
Mocking zustand store for jest test
How to call Zustand / React hook outside of React component?

Spent hours looking online for the actual canonical answer for something so trivial.