I’ve been doing the Get Started elixir. I’m currently going part 9 of MIX AND OTP, but I am having an error with the Doctests that I cannot fix:

I have this command parser file just as the tutorial tells me:

defmodule KVServer.Command do
  @doc ~S"""
  Parses the given `line` into a command.

  ## Examples

      iex> KVServer.Command.parse "CREATE shopping\r\n"
      {:ok, {:create, "shopping"}}

      iex> KVServer.Command.parse "CREATE  shopping  \r\n"
      {:ok, {:create, "shopping"}}

      iex> KVServer.Command.parse "PUT shopping milk 1\r\n"
      {:ok, {:put, "shopping", "milk", "1"}}

      iex> KVServer.Command.parse "GET shopping milk\r\n"
      {:ok, {:get, "shopping", "milk"}}

      iex> KVServer.Command.parse "DELETE shopping eggs\r\n"
      {:ok, {:delete, "shopping", "eggs"}}

  Unknown commands or commands with the wrong number of
  arguments return an error:

      iex> KVServer.Command.parse "UNKNOWN shopping eggs\r\n"
      {:error, :unknown_command}

      iex> KVServer.Command.parse "GET shopping\r\n"
      {:error, :unknown_command}

  """

  def parse(line) do
    case String.split(line) do
      ["CREATE", bucket] -> {:ok, {:create, bucket}}
      ["GET", bucket, key] -> {:ok, {:get, bucket, key}}
      ["PUT", bucket, key, value] -> {:ok, {:put, bucket, key, value}}
      ["DELETE", bucket, key] -> {:ok, {:delete, bucket, key}}
      _ -> {:error, :unknown_command}
    end
  end

  @doc """
  Runs the given command.
  """
  def run(command)

  def run({:create, bucket}) do
    MixTest.Registry.create(MixTest.Registry, bucket)
    {:ok, "OK\r\n"}
  end

  def run({:get, bucket, key}) do
    lookup(bucket, fn pid ->
      value = MixTest.Bucket.get(pid, key)
      {:ok, "#{value}\r\nOK\r\n"}
    end)
  end

  def run({:put, bucket, key, value}) do
    lookup(bucket, fn pid ->
      MixTest.Bucket.put(pid, key, value)
      {:ok, "OK\r\n"}
    end)
  end

  def run({:delete, bucket, key}) do
    lookup(bucket, fn pid ->
      MixTest.Bucket.delete(pid, key)
      {:ok, "OK\r\n"}
    end)
  end

  defp lookup(bucket, callback) do
    case MixTest.Registry.lookup(MixTest.Registry, bucket) do
      {:ok, pid} -> callback.(pid)
      :error -> {:error, :not_found}
    end
  end
end

Note: MixTest is my module from another application that is under umbrella (KV module in the tutorial).

When I try to run the tests, all the doc tests fail, apparently because it does not recognize a blank space or something that I do not understand.

These are the messages that the console shows me when I run the mix test command:

==> kv_server


  1) doctest KVServer.Command.parse/1 (2) (KVServer.CommandTest)
     apps/kv_server/test/kv_server/command_test.exs:3
" (column 49, code point U+000D)t: (SyntaxError) lib/kv_server/command.ex:10:49: unexpected token: "
     doctest:
       iex> KVServer.Command.parse "CREATE  shopping  \r\n"
       {:ok, {:create, "shopping"}}
     stacktrace:
       lib/kv_server/command.ex:10: KVServer.Command (module)



  2) doctest KVServer.Command.parse/1 (3) (KVServer.CommandTest)
     apps/kv_server/test/kv_server/command_test.exs:3
" (column 50, code point U+000D)t: (SyntaxError) lib/kv_server/command.ex:13:50: unexpected token: "
     doctest:
       iex> KVServer.Command.parse "PUT shopping milk 1\r\n"
       {:ok, {:put, "shopping", "milk", "1"}}
     stacktrace:
       lib/kv_server/command.ex:13: KVServer.Command (module)



  3) doctest KVServer.Command.parse/1 (4) (KVServer.CommandTest)
     apps/kv_server/test/kv_server/command_test.exs:3
" (column 48, code point U+000D)t: (SyntaxError) lib/kv_server/command.ex:16:48: unexpected token: "
     doctest:
       iex> KVServer.Command.parse "GET shopping milk\r\n"
       {:ok, {:get, "shopping", "milk"}}
     stacktrace:
       lib/kv_server/command.ex:16: KVServer.Command (module)



  4) doctest KVServer.Command.parse/1 (6) (KVServer.CommandTest)
     apps/kv_server/test/kv_server/command_test.exs:3
" (column 52, code point U+000D)t: (SyntaxError) lib/kv_server/command.ex:25:52: unexpected token: "
     doctest:
       iex> KVServer.Command.parse "UNKNOWN shopping eggs\r\n"
       {:error, :unknown_command}
     stacktrace:
       lib/kv_server/command.ex:25: KVServer.Command (module)



  5) doctest KVServer.Command.parse/1 (7) (KVServer.CommandTest)
     apps/kv_server/test/kv_server/command_test.exs:3
" (column 43, code point U+000D)t: (SyntaxError) lib/kv_server/command.ex:28:43: unexpected token: "
     doctest:
       iex> KVServer.Command.parse "GET shopping\r\n"
       {:error, :unknown_command}
     stacktrace:
       lib/kv_server/command.ex:28: KVServer.Command (module)



  6) doctest KVServer.Command.parse/1 (1) (KVServer.CommandTest)
     apps/kv_server/test/kv_server/command_test.exs:3
" (column 46, code point U+000D)t: (SyntaxError) lib/kv_server/command.ex:7:46: unexpected token: "
     doctest:
       iex> KVServer.Command.parse "CREATE shopping\r\n"
       {:ok, {:create, "shopping"}}
     stacktrace:
       lib/kv_server/command.ex:7: KVServer.Command (module)



  7) doctest KVServer.Command.parse/1 (5) (KVServer.CommandTest)
     apps/kv_server/test/kv_server/command_test.exs:3
" (column 51, code point U+000D)t: (SyntaxError) lib/kv_server/command.ex:19:51: unexpected token: "
     doctest:
       iex> KVServer.Command.parse "DELETE shopping eggs\r\n"
       {:ok, {:delete, "shopping", "eggs"}}
     stacktrace:
       lib/kv_server/command.ex:19: KVServer.Command (module)

.

Finished in 0.1 seconds (0.1s async, 0.00s sync)
7 doctests, 1 test, 7 failures