what does or doesn't trigger "on attack" procs?

[Guurzak]

So if I have a weapon like the Quillthrower of Dreeg with a 33% chance on attack of activating its proc, what all will qualify for an activation roll?

• Obviously, any weapon attacks with that weapon
• I’m pretty sure that spellcasting while the weapon is held will also do it. (Even if there’s no weapon damage component?)
• Offensive auras like Night’s Chill?
• Pretty sure that standard pets (e.g. Briarthorn) do not set it off. What about quasipets like mortars or blade spirits?
• What about other procs, like the reactive proc on Arcane Harmony leggings?
• Persistent effect like Elemental Storm?
• Each missile of an ongoing barrage like Blizzard? Or just the initial cast?

[MortalKombat]

So if I have a weapon like the Quillthrower of Dreeg with a 33% chance on attack of activating its proc, what all will qualify for an activation roll?

• Obviously, any weapon attacks with that weapon
• I’m pretty sure that spellcasting while the weapon is held will also do it. (Even if there’s no weapon damage component?)
• Offensive auras like Night’s Chill?
• Pretty sure that standard pets (e.g. Briarthorn) do not set it off. What about quasipets like mortars or blade spirits?
• What about other procs, like the reactive proc on Arcane Harmony leggings?
• Persistent effect like Elemental Storm?
• Each missile of an ongoing barrage like Blizzard? Or just the initial cast?

Everything will qualify. Any instance of damage tick, or non-damage effect application, will have a chance to trigger a proc.