Shatterspike

From Tales From the Yawning Portal, page 229.

Description
''Weapon (longsword), uncommon (requires attunement). 3 lbs.''

You have a +1 bonus to attack and damage rolls made with this magic weapon. If it hits an object, the hit is automatically a critical hit, and it can deal bludgeoning or slashing damage to the object (your choice). Further, damage from nonmagical sources can't harm the weapon.