rickvanlieshout.com/internal/testing/__mocks__/gatsby.ts

import React from "react";

const gatsby = jest.requireActual("gatsby");

export default {
  ...gatsby,
  graphql: jest.fn(),
  Link: jest.fn().mockImplementation(({ to, ...rest }) =>
    React.createElement("a", {
      ...rest,
      href: to,
    }),
  ),
  StaticQuery: jest.fn(),
  useStaticQuery: jest.fn(),
};