Was there an official decision to migrate from Enzyme to Testing Library?

[grahamalama]

Forgive me if this should go in Q&A, but I'm not necessarily looking for help -- I'm more looking for the reasoning behind a decision.

I know that Testing Library is the go-to choice for testing React apps these days. It seems fitting then that it was introduced here in create-react-app as the default component testing library.

I also noticed that references to Enzyme were taken out of the documentation, further cementing Testing Library as the, well, testing library of choice for CRA.

Was there an official decision behind this transition, or did it "just happen"? I'd like to spread the good word of Testing Library, and I feel like it would be a bit easier if I could point to some blog post (or even commit message) that's basically: Here's why we migrated from Enzyme to Testing Library....

[john-james-gh]

React Testing Library is a set of helpers that let you test React components without relying on their implementation details. This approach makes refactoring a breeze and also nudges you towards best practices for accessibility. Although it doesn’t provide a way to “shallowly” render a component without its children, a test runner like Jest lets you do this by mocking.

source: https://reactjs.org/docs/testing.html

If you’d like to test components in isolation from the child components they render, we recommend using react-testing-library. react-testing-library is a library for testing React components in a way that resembles the way the components are used by end users. It is well suited for unit, integration, and end-to-end testing of React components and applications. It works more directly with DOM nodes, and therefore it's recommended to use with jest-dom for improved assertions.

source: https://create-react-app.dev/docs/running-tests

I think this is the closest to an official statement you will get about the topic you are asking.
Also, "without relying on their implementation details" is alluding towards Enzyme's ability to test implementation details.

Fact is, many developers were mistakenly using this ability to test React components the "wrong way". In order to prevent that - the decision was made to move away from Enzyme and promote the "right way" of testing React components.

There is also this blog post by the author of testing-library https://kentcdodds.com/blog/testing-implementation-details which I'd say fueled the transition.

The blog was originally posted on Feb 8, 2019 which is much before the transiton was made
date of blog post