What to do about shared tests between projects?

[DanielStoica85]

Let's say you are working on two separate projects, which are in two separate repositories, but which have many common functionalities, React components, pages, etc. You want to add e2e tests for both of them with Cypress and some of them will apply for both projects. Where do you place those tests? In both repositories? In one common repo? What would be the best approach in this case?