...anyone know what they might be? Growing in a garden nearby. Dunno whether to eat them or not

You'd need to give a better description, or better yet, a photo, but the golden rule of foraging is: if in doubt, DON'T eat it.

Sounds like Mahonia, large spiky leaves, yellow flowers followed by the blue berries. As far as I'm aware they aren't edible.

That's it! Thank you