ReactTestUtils.renderIntoDocument() resources clean up and documentation

[the-spyke]

Do you want to request a feature or report a bug?

Feature/documentation

What is the current behavior?

There is almost none documentation about how to actually use .renderIntoDocument() method. I can't find find answers on those questions on Jest's website or enzyme's (I know that it's not Facebook) either.

• If I render a component into a DOM in a test, how will it be destroyed?
• Should I clean up by myself?
• What tools to use for this?
• Just .unmountComponentAtNode()?
• Where I will get the container to pass in?
• What about additional component trees like in Popovers?
• What are the best ways to test that there aren't any parts left after my component were unmounted?

If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem via https://jsfiddle.net or similar (template: https://jsfiddle.net/84v837e9/).

What is the expected behavior?

It will be nice to see such information before people will met memory leaks in their tests, and also help to establish good practices for writing tests.

Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?

[the-spyke]

Answering my own questions:

• Calling .renderIntoDocument() returns you an instance
• This instance was rendered into freshly created DOM element, which now represents a detached tree
• There's also a reference to the instance in ReactDOM's internal map
• So, even if you remove all your references to this instance, on every call to .renderIntoDocument() you will get 1 detached tree hanging in memory + 1 instance of a React component with all its props not available for garbage collection

[bvaughn]

Thank you for filing this issue! 😄

The documentation and source code for reactjs.org now lives in a different repository: reactjs/reactjs.org. (For more info on why we made this move, see issue #11075.)

I've moved your issue to the new repo: reactjs/react.dev#28

Let's continue the discussion there! Sorry for the inconvenience.