How The New York Times systematically migrated from Enzyme into React Testing Library | by Felipe Buenano | The NYT Open Team | NYT Open

As part of our efforts to maintain and improve the functionality and performance of The New York Times core website, we recently upgraded our React library from React 16 into React 18. One of the biggest challenges we faced in the process was transforming our codebase from the Enzyme test utility into the React Testing Library. There are some major key differences in unit testing between these two libraries. Enzyme generates a string representation of the DOM tree. React objects are accessible through Enzyme methods. On the other hand, React Testing Library generates an actual representation of the DOM tree, where React elements are no longer reachable but are rendered as part of the DOM as a whole.