spinning melee turtle help

newby here, this is my code not sure whats wrong

while turtle.detect() do
turtle.attack()
turtle.suck()
repeat
turtle.turnLeft()
until turtle.detect()
end

The turtle.detect function only detects blocks. There is no built-in function to detect the presence of an entity.

… other than turtle.attack(), that is - even if that's not its primary purpose. It can only "detect" that which it can attack, but that happens to fit your needs anyway:

while true do
  if turtle.attack() then
    turtle.suck()
  else
    turtle.turnLeft()
  end
end