RefuelDigger

-- pastebin get 180C8NRw RefuelDigger

local function isTurtleBlock(data)
    return data and type(data.name) == "string" and data.name:match("computercraft:turtle")
end

local function dropOffInventory(itemName)
    for i = 1, 16 do
        if turtle.getItemCount(i) > 0 then
            if itemName then
                local data = turtle.getItemDetail(i)
                if data.name == itemName then
                    turtle.select(i)
                    turtle.drop()
                end
            else
                turtle.select(i)
                turtle.drop()
            end
        end
    end
end

local cnt = 0
while cnt < 4 do
    local success, data = turtle.inspect()
    if success and data.name == "minecraft:chest" then
        turtle.turnLeft()
        turtle.turnLeft()
        break
    end
    turtle.turnLeft()
    cnt = cnt + 1
end

while true do
    local success, data = turtle.inspect()
    if success and isTurtleBlock(data) then
        sleep(0.5)
        turtle.dig()
        turtle.turnLeft()
        turtle.turnLeft()
        dropOffInventory()
        turtle.turnLeft()
        turtle.turnLeft()
    end
    sleep(0.5)
end