Setup Dialyxir and Credo code analyzers:

- Refactor codebase according to analyzers

lib/router.ex

@@ -1,10 +1,14 @@
 defmodule Shortnr.Router do
+  @moduledoc """
+  This module contains the Router for the Shortnr application. Do not import, other than
+  Application entry.
+  """
   use Plug.ErrorHandler
   use Plug.Router
 
   require Logger
 
-  alias Shortnr.Transport.{Text, HTTP}
+  alias Shortnr.Transport.{HTTP, Text}
   alias Shortnr.URL
 
   plug(Plug.Logger, log: :debug)

lib/shortnr.ex

@@ -1,6 +1,6 @@
 defmodule Shortnr do
   @moduledoc """
-  Documentation for Shortnr.
+  The Shortnr application entry point. Check README for usage documenation.
   """
 
   use Application

lib/transport/http.ex

@@ -1,8 +1,13 @@
 defmodule Shortnr.Transport.HTTP do
+  @moduledoc """
+  This module contains functions that can be used to handle HTTP requests and send responses, by
+  manipulating Plug.Conn.
+  """
+
   import Plug.Conn
 
-  @type ok_error :: {:ok, term(), Plug.Conn.t()} | error()
   @type error :: {:error, {atom(), String.t()}, Plug.Conn.t()}
+  @type ok_error :: {:ok, term(), Plug.Conn.t()} | error()
 
   @spec handle(ok_error(), (... -> ok_error())) :: ok_error()
   def handle(error = {:error, _sub_error, _conn}, _func), do: error

lib/transport/json.ex

@@ -1,28 +0,0 @@
-defmodule Shortnr.Transport.Json do
-  import Plug.Conn
-  alias Shortnr.Transport.HTTP
-
-  @spec decode_request(Plug.Conn.t(), module()) :: HTTP.ok_error()
-  def decode_request(conn, struct_module) do
-    {:ok, body, conn} = read_body(conn)
-    {:ok, params} = Jason.decode(body)
-
-    params_list =
-      params
-      |> Map.to_list()
-      |> Enum.map(fn {key, value} -> {String.to_atom(key), value} end)
-
-    {:ok, struct(struct_module, params_list), conn}
-  end
-
-  @spec encode_response(HTTP.ok_error()) :: HTTP.ok_error()
-  def encode_response({:error, {status, response}, conn}) do
-    {:ok, json_body} = Jason.encode(%{data: response})
-    {:error, {status, json_body}, conn}
-  end
-
-  def encode_response({:ok, response, conn}) do
-    {:ok, json_body} = Jason.encode(%{data: response})
-    {:ok, json_body, conn}
-  end
-end

lib/transport/text.ex

@@ -1,4 +1,8 @@
 defmodule Shortnr.Transport.Text do
+  @moduledoc """
+  This modules contains functions to decode and encode text formatted http requests and responses.
+  """
+
   import Plug.Conn
   alias Shortnr.Transport.HTTP
   alias Shortnr.URL

lib/transport/transport.ex

@@ -1,4 +1,7 @@
 defmodule Shortnr.Transport do
+  @moduledoc """
+  This module houses generic Transport types.
+  """
   @type error :: {:error, {atom(), String.t()}}
   @type ok_error :: {:ok, term()} | error()
 end

lib/url/repo/ets.ex

@@ -1,4 +1,8 @@
 defmodule Shortnr.URL.Repo.ETS do
+  @moduledoc """
+  This module is an implemention of the Repo behaviour using the Erlang ETS library.
+  """
+
   @behaviour Shortnr.URL.Repo
 
   @impl true
@@ -16,7 +20,7 @@ defmodule Shortnr.URL.Repo.ETS do
   end
 
   @impl true
-  def list() do
+  def list do
     resp = ets().select(:urls, [{:"$1", [], [:"$1"]}])
     {:ok, resp |> Enum.map(&elem(&1, 1))}
   end

lib/url/repo/repo.ex

@@ -1,6 +1,11 @@
 defmodule Shortnr.URL.Repo do
-  alias Shortnr.URL
+  @moduledoc """
+  This module defines the Repo behaviour for the URL service. All Repos must implement this
+  entire behaviour.
+  """
+
   alias Shortnr.Transport
+  alias Shortnr.URL
 
   @callback put(URL.t()) :: :ok | Transport.error()
   @callback get(String.t()) :: {:ok, URL.t()} | Transport.error()

lib/url/url.ex

@@ -1,6 +1,9 @@
 defmodule Shortnr.URL do
+  @moduledoc """
+  This module represents both the URL data object, in the form of a struct, and the URL business
+  domain service.
+  """
   alias Shortnr.Transport
-  alias Shortnr.URL
   alias Shortnr.URL.Util
 
   defstruct id: "",
@@ -17,7 +20,7 @@ defmodule Shortnr.URL do
 
   @spec create(String.t(), module()) :: {:ok, String.t()} | Transport.error()
   def create(url, repo) do
-    url_struct = %URL{id: Util.gen_id(), url: URI.parse(url)}
+    url_struct = %__MODULE__{id: Util.gen_id(), url: URI.parse(url)}
 
     {:ok, extant_url} = repo.get(url_struct.id)
 
@@ -29,17 +32,17 @@ defmodule Shortnr.URL do
     end
   end
 
-  @spec get(String.t(), module()) :: {:ok, URL.t()} | Transport.error()
+  @spec get(String.t(), module()) :: {:ok, t()} | Transport.error()
   def get(key, repo) do
     {:ok, _} = repo.get(key)
   end
 
-  @spec list(module()) :: {:ok, list(URL.t())} | Transport.error()
+  @spec list(module()) :: {:ok, list(t())} | Transport.error()
   def list(repo) do
     {:ok, _} = repo.list
   end
 
-  @spec delete(String.t(), module()) :: {:ok, :ignore} | Tranpsport.error()
+  @spec delete(String.t(), module()) :: {:ok, String.t()} | Transport.error()
   def delete(key, repo) do
     :ok = repo.delete(key)
     {:ok, "Success"}

lib/url/util.ex

@@ -1,4 +1,7 @@
 defmodule Shortnr.URL.Util do
+  @moduledoc """
+  URL module utility functions.
+  """
   @id_chars String.codepoints("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXWYZ0123456789")
   @spec gen_id() :: String.t()
   def gen_id do