2x2 spruce

function move()
    turtle.dig()
    turtle.forward()
end

function turn()
    turtle.turnRight()
    move()
end

function chopUp()
    while turtle.detectUp() do
        turtle.digUp()
        turtle.up()
    end
end

function checkBelow()
    if turtle.detectDown() then
        success, data = turtle.inspectDown()
        if success then
            if data.name ~= "minecraft:log" or data.name ~= "minecraft:leaves" then
                return false
            else
                return true
            end
        end
    else
        return false
    end
end


function chopDown()
    repeat
        turtle.digDown()
        turtle.down()
    until not checkBelow()
end

function placeSapling()
    turtle.select(2)
    turtle.place()
    turtle.select(1)
end

function reUp()
    if turtle.getItemCount(1) == 0 then
        turtle.select(1)
        turtle.suckDown()
    end
end

function treeGrew()
    local success, data = turtle.inspect()
    if success then
        if data.name == "minecraft:log" or data.name == "minecraft:log"then
            return true;
        else
            return false;
        end
    end
end

function growTree()
    repeat
        reUp()
        turtle.place()
    until treeGrew()
end


while true do
    growTree()
    move()
    chopUp()
    move()
    chopUp()
    chopDown()
    turn()
    chopUp()
    move()
    chopUp()
    chopDown()
    turn()
    placeSapling()
end