feat(FelaComponent): Allow style prop with empty value

[TxHawks]

Description

Since v10, FelaComponent throws if the style prop is null or undefined, which I think is wrong.

It's quite an edge case, but sometimes one may want an element to only be styled under certain conditions, and have that be determined dynamically.

The easiest and most straightforward way to do that is to pass null to FelaComponent's style prop from the parent component.

By removing the check and throw statement, it works as expected, so I don't really see any benefit in having it there. It doesn't really add any DX value, and is overly restrictive

Example

function MaybeStyled({ style, children, }) {
  return (<FelaComponent style={style}>{children}</FelaComponent>);
}


<MaybeStyle style={null} /> // renders <div></div>
<MaybeStyle style={{ color: 'red', }} /> // renders <div class="a"></div>

Packages

fela-bindings

Versioning

Patch

Checklist

Quality Assurance

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• The code was formatted using Prettier (yarn run format)
• The code has no linting errors (yarn run lint)
• All tests are passing (yarn run test)
• There are no flow-type errors (yarn run flow)

Changes

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• Tests have been added/updated
• Documentation has been added/updated
• My changes have proper flow-types

[robinweser]

The point was that you don't need a wrapping FelaComponent without a style as you can simply render a div as well. But fair enough, it seems like a legit use case to pass undefined / null.

[robinweser]

I will merge it in and release for now, but maybe we should log a warning in devMode? So people see that path and might fix it later on. I don't think sth. like that will ever get a perf issue, but after all we render unnecessary components here.

[TxHawks]

but maybe we should log a warning in devMode?

Happy to do this. Did you release already?

[robinweser]

Not yet, but was about to do that soonish. But I'll have another release at the end of the week anyways :P

[TxHawks]

Actually, how would you know if we are in dev mode inside FelaComponent?

[robinweser]

renderer.devMode

[TxHawks]

Work just got really crazy, I don't think I'll manage to get to it today. Let's jus make sure to do this later