The issue as I see it: Spell sniper requires a spell with a range. Booming blade has a range of Self, so would not qualify despite the (5-foot radius) of the spell. This is why (or at least one reason) the booming blade spell's range was changed from 5 feet.I heard Tasha's Cauldron of Everything changed the Spell sniper + booming blade + reach weapon combo.
Can someone please confirm to me if the combo still applies?
Thanks in advance.
The spell clearly says the range is "self" not 5'Longsword (Non-Reach weapon) + Booming Blade + Spell Sniper = 5ft Spell range.
You are still using the old text. It was changed.The cantrip Booming Blade's range is extended to 10ft
@Paul Farquhar is correct. Here is the spell now:The cantrip Booming Blade's range is extended to 10ft, when paired with a reach weapon. That has not changed.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.