An interesting combo emerged in the game: an invisible member of the group chose to defend another member of the group using their no attack or spell reaction (arrow capture shield).
This led to two questions:
In the description for the invisibility Spell (PH page 254), says:
The spell ends for a target that attacks or casts a spell.
So this led to the question: Does this reaction end with invisibility?
In the description for the shield that catches arrows, He says
Also, each time an attacker makes a remote attack against a
target within 5 feet of you, you can use your reaction to become the
target the attack instead.
In fact, there is a long list of reactions without spells, without attacks that you can take (Bardic Inspiration, Detour, etc.) that can affect an attack.
Question 1: Does this type of reaction end the invisibility spell?
The consensus at the table was "No. It is neither a spell nor an attack."
But wait, there is more!
According to the rules of the invisible Condition (PHB, page 291):
Attack rolls against you have a disadvantage.
In theory, the attack should now be at a disadvantage, even if it has already taken place.
This left us all scratching our heads (and the normal attack failed anyway, so we moved on)
Question 2: Does the redirection of an attack to an invisible target now cause the attack to be performed at a disadvantage?