Summary

Fixes #6391

React trims a "padding" whitespaces inside a element when it contains at least one line break; whitespaces without line breaks will never be trimmed and should be considered as a valid text node.

For example, the following code:

<> </>

is equivalent to:

<>{" "}</>

There is the same logic in react/jsx-no-unnecessary-fragment: https://github.com/jsx-eslint/eslint-plugin-react/blob/f2869fd6dc76ceb863c5e2aeea8bf4d392508775/lib/rules/jsx-no-useless-fragment.js#L116-L125

Test Plan