2 ms·

Except when you test that something is not an instance of something else and the test wrongly passes. Then you'll be scratching your head trying to fix a bug

by afro88 3y ago

Except when you test that something is *not* an instance of something else and the test wrongly passes. Then you'll be scratching your head trying to fix a bug already in production.

awestroke 3y ago
I've never written such a test assertion in my life. I'll be fine with Jest
Zetice 3y ago
That's no the issue, the issue is if the code you can't access or control uses `instanceof`. If the only problem was you needed to avoid `instanceof` in tests, this wouldn't matter at all.