The Roguish Archetype Swashbuckler (SCAG/XGtE) has the following feature:
When you choose this archetype at 3rd level, you learn how to land a strike and then slip away without reprisal. During your turn, if you make a melee attack against a creature, that creature can't make opportunity attacks against you for the rest of your turn.
The cantrip Booming Blade (SCAG) says the following:
As part of the action used to cast this spell, you must make a melee attack with a weapon against one creature within the spell's range, otherwise the spell fails.
Does Fancy Footwork apply (no OA from the attacked creature) if you attacked it with Booming Blade (or Green Flame Blade)?
More generally, since it does not specify a weapon attack, does Fancy Footwork apply to melee spell attacks as well?