yatender-oktalk

  defmodule ExChain.BlockchainTest do

....

   test "validate a chain", %{blockchain: blockchain} do
      # add block into blockchain
      blockchain = Blockchain.add_block(blockchain, "some-block-data")
      # assert if blockchain is valid
      assert Blockchain.valid_chain?(blockchain)
    end

yatender-oktalk

defmodule ExChain.Blockchain do
  @moduledoc """
  This module contains the blockchain related functions
  """

....

  @spec add_block(BlockChain.t(), any) :: BlockChain.t()
  def add_block(blockchain = %__MODULE__{chain: chain}, data) do
    {last_block, _} = List.pop_at(chain, -1)

yatender-oktalk

defmodule ExChain.Blockchain do
  @moduledoc """
  This module contains the blockchain related functions
  """
  alias __MODULE__
  alias ExChain.Blockchain.Block

  defstruct ~w(chain)a

  @type t :: %Blockchain{

yatender-oktalk

defmodule ExChain.BlockchainTest do
  @moduledoc """
  This module contains test related to a blockchain
  """

  use ExUnit.Case

  alias ExChain.Blockchain
  alias ExChain.Blockchain.Block

yatender-oktalk

defmodule ExChain.Blockchain.BlockTest do
  @moduledoc """
  This module contains test related to a block
  """

  use ExUnit.Case
  alias ExChain.Blockchain.Block

  describe "block" do
    test "genesis is valid" do

yatender-oktalk

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(),

yatender-oktalk

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(),

yatender-oktalk

defmodule ExChain.Blockchain.BlockTest do
  @moduledoc """
  This module contains test related to a block
  """

  use ExUnit.Case
  alias ExChain.BlockChain.Block

  describe "block" do
    test "genesis is valid" do

yatender-oktalk

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(),

yatender-oktalk

defmodule ExChain.BlockChain.Block do
  @moduledoc """
    This module is the single block struct in a blockchain
  """
  
  defstruct ~w(timestamp last_hash hash data)a
 end