exchain-blockchain-block-genesis-new.ex

defmodule ExChain.BlockChain.Block do
  @moduledoc """
  This module is the single block struct in a blockchain
  """

  alias __MODULE__

  @type t :: %Block{
          timestamp: pos_integer(),
          last_hash: String.t(),
          hash: String.t(),
          data: any()
        }

  defstruct ~w(timestamp last_hash hash data)a

  @spec new(pos_integer(), String.t(), any()) :: Block.t()
  def new(timestamp, hash, last_hash, data) do
    %__MODULE__{timestamp: timestamp, last_hash: last_hash, hash: hash, data: data}
  end

  @spec genesis() :: Block.t()
  def genesis() do
    __MODULE__.new(1_599_909_623_805_627, "genesis-hash", "-", "genesis data")
  end
end

Hey, great tutorial, but line 17 needs to be: @spec new(pos_integer(), String.t(), String.t(), any()) :: Block.t() - there is a missing String.t()