3x3 turtle tunnel

local Arg = {...}

local function getBlockName()
    local isThere , blockInfo = turtle.inspect()
    if isThere then
        return blockInfo.name
    end
    return "air"
end

local function getBlockNameUp()
    local isThere , blockInfo = turtle.inspectUp()
    if isThere then
        return blockInfo.name
    end
    return "air"
end

local function checkIfMineble(blockname)
    print("im looking at ", blockname)
    if string.lower(blockname) == "minecraft:bedrock" then
        return false
    end
    return true
end

local function tryDigUntilClear()
    if checkIfMineble(getBlockName()) then
        while turtle.detect() do
            turtle.dig()
        end
    end
end

local function tryDigUpUntilClear()
    if checkIfMineble(getBlockNameUp()) then
        while turtle.detectUp() do
            turtle.digUp()
        end
    end
end

local tunnellenght = Arg[1]

while tunnellenght ~= 0 do
    tryDigUntilClear()
    turtle.forward()
    turtle.turnRight()
    for i =1 , 2 ,1 do
        tryDigUntilClear()
        tryDigUpUntilClear()
        turtle.up()
    end
    tryDigUntilClear()
    turtle.turnLeft()
    turtle.turnLeft()
    for i =1 , 2 ,1 do
        tryDigUntilClear()
        turtle.down()
    end
    tryDigUntilClear()
    turtle.turnRight()
    tunnellenght = tunnellenght - 1
end