Return of empty string results in class=""

I can wrap this function in a comparison function and make className undefined myself, but was wondering if this was the best way. I’d looked through the issues and was surprised no one has raised this issue before.

In the real world, I’d probably wrap this library in a library level utility that does this and not repeat the object twice. This is of course specific to React which sees an empty string and undefined differently.

className={classNames({
				'slds-is-today': isToday,
				'slds-disabled-text': !isCurrentMonth,
				'slds-is-selected': isSelectedDay
			}) === '' ? undefined : classNames({
				'slds-is-today': isToday,
				'slds-disabled-text': !isCurrentMonth,
				'slds-is-selected': isSelectedDay
			})

[Noitidart]

I had this exact same issue today haha! I’m like why the heck are there all these blank class attributes. I did this for now:

file: react-classnames

// classnames returns blank string when it fails, it should be returned undefined for react
import classnames from 'classnames';

const classnamesUndefined = (...args) => classnames(...args) || undefined;

export default classnamesUndefined;

[dcousens]

Excellent question, but unfortunately changing it would be API incompatible as many users use concatenation with other strings post-haste which would cause "undefined" to be concatenated if changed now.