[feat] config to allow <></> in no-useless-fragment

[sbdchd]

Problem Description

Sometimes APIs will type their inputs as JSX.Element, in which case, you’ll need to pass in an empty fragment instead of null.

<Foo bar={<></>}/>

Or the return type of the component is typed as JSX.Element so you return <></> while loading

Alternative Solutions

Migrating away from <></> is too much work

Feature Details

allowEmptyFragment: boolean = false

Examples

allowEmptyFragment: true

And then you could use <></>

Evaluation Checklist

• I have had problems that this feature would solve
• I could not find a way to solve the problem with existing features or workarounds
• I have thought very hard about potential edge cases and downsides, and they are acceptable
• I think the feature is well-defined and would provide clear value to users