I constantly create square background which I should adjust to artboard size.
Almost every time I miss one or two pixels (Retina is good for that), so I looked for one-click feature "click object to artboard size" and didn't find it.
Probably there is a faster way instead of inserting exact parameters of the artboard to the square dimensions?
Object > Artboards > Fit to Artwork. That will make the artboard fit precisely to the edge of all the artwork, including the background square.
There is no command to scale artwork to match the artboard.