Why does `settled` make a test pass after `render`?

[boris]

@balint

Is it that calling settled takes a minuscule amount of time but enough for the onError callback to run? Is it something else?

I believe that’s the reason, yes. As you mention yourself, settled is not “clever” enough to know about external promises/DOM callbacks so it’s just a race-condition. The test could theoretically fail, just less likely. I would do as @dknutsen said - use waitFor. It’s a wonderful tool!