For async: show a loading indicator / state

[djfpaagman]

To make clear to the user that data is loading.

I like how it's implemented in React Select: it shows a "loading" message in the combobox and has a loading indicator on the right side inside the input.

[josefarias]

I've gone back and forth on this. I think spinners can be a crutch in this case. My (possibly incorrect) take is most implementers should be able to return search results fast enough that the spinner isn't necessary. I do expect caching and SQL optimizations to be necessary in some cases.

I think if async loading is slow enough that it requires showing a spinner — that points to the implementer having to do some work to optimize fetching their results. And providing a spinner by default removes that positive pressure.

Open to having my mind changed though!