v0.1: Flesh out library with all types in isn

Restructuring: Isn.Extension is now called Isn, which means that the postgrex
configuration line becomes a bit shorter now:

```elixir
{:ok, pid} = Postgrex.Connection.start_link(
  database: "isn_test",
  extensions: [{Isn, {}}])
```

instead of the previous version, with `extensions: [{Isn.Extension, {}}]`.

I also implement the entire library in the `lib/isn.ex` file, since it felt
pretty silly to have eight different one-line files under `lib/isn/` looking
like this: `defmodule Isn.ISBN, do: use(Isn.Base, :isbn)`

We now have the following types:

- ISBN
- ISBN13
- ISMN
- ISMN13
- ISSN
- ISSN13
- EAN13
- UPC

lib/isn.ex

@@ -0,0 +1,55 @@
+defmodule Isn do
+  alias Postgrex.TypeInfo
+
+  @behaviour Postgrex.Extension
+  @isn ~w(ean13 isbn13 ismn13 issn13 isbn ismn issn upc)
+
+  def init(parameters, _opts),
+    do: parameters
+
+  def matching(_library),
+    do: Enum.reduce(@isn, [], fn(t, ack) -> ack ++ [type: t] end)
+
+  def format(_),
+    do: :text
+
+  def encode(%TypeInfo{type: type}, binary, _types, _opts) when type in @isn,
+    do: binary
+
+  def decode(%TypeInfo{type: type}, binary, _types, _opts) when type in @isn,
+    do: binary
+end
+
+defmodule Isn.Base do
+  defmacro __using__(isn_type) do
+    quote bind_quoted: [isn_type: isn_type] do
+      # @behaviour Ecto.Type
+      #
+      @isn_type isn_type
+      @moduledoc """
+      Definition for the #{@isn_type} module.
+      """
+
+      def type,
+        do: @isn_type
+
+      defdelegate blank?, to: Ecto.Type
+
+      def cast(nil), do: :error
+      def cast(isn), do: {:ok, to_string(isn)}
+
+      def load(isn), do: {:ok, to_string(isn)}
+
+      def dump(isn), do: {:ok, to_string(isn)}
+    end
+  end
+end
+
+defmodule Isn.ISBN,   do: use(Isn.Base, :isbn)
+defmodule Isn.ISMN,   do: use(Isn.Base, :ismn)
+defmodule Isn.ISSN,   do: use(Isn.Base, :issn)
+defmodule Isn.ISBN13, do: use(Isn.Base, :isbn13)
+defmodule Isn.ISMN13, do: use(Isn.Base, :ismn13)
+defmodule Isn.ISSN13, do: use(Isn.Base, :issn13)
+defmodule Isn.UPC,    do: use(Isn.Base, :upc)
+defmodule Isn.EAN13,  do: use(Isn.Base, :ean13)

lib/isn/base.ex

@@ -1,24 +0,0 @@
-defmodule Isn.Base do
-  defmacro __using__(isn_type) do
-    quote bind_quoted: [isn_type: isn_type] do
-      # @behaviour Ecto.Type
-      #
-      @isn_type isn_type
-      @moduledoc """
-      Definition for the #{@isn_type} module.
-      """
-
-      def type,
-        do: @isn_type
-
-      defdelegate blank?, to: Ecto.Type
-
-      def cast(nil), do: :error
-      def cast(isn), do: {:ok, to_string(isn)}
-
-      def load(isn), do: {:ok, to_string(isn)}
-
-      def dump(isn), do: {:ok, to_string(isn)}
-    end
-  end
-end

lib/isn/extension.ex

@@ -1,21 +0,0 @@
-defmodule Isn.Extension do
-  alias Postgrex.TypeInfo
-
-  @behaviour Postgrex.Extension
-  @isn ~w(ean13 isbn13 ismn13 issn13 isbn ismn issn upc)
-
-  def init(parameters, _opts),
-    do: parameters
-
-  def matching(_library),
-    do: Enum.reduce(@isn, [], fn(t, ack) -> ack ++ [type: t] end)
-
-  def format(_),
-    do: :text
-
-  def encode(%TypeInfo{type: type}, binary, _types, _opts) when type in @isn,
-    do: binary
-
-  def decode(%TypeInfo{type: type}, binary, _types, _opts) when type in @isn,
-    do: binary
-end

lib/isn/isbn13.ex

@@ -1,3 +0,0 @@
-defmodule Isn.ISBN13 do
-  use Isn.Base, :isbn13
-end

mix.exs

@@ -1,7 +1,7 @@
 defmodule Isn.Mixfile do
   use Mix.Project
 
-  @version "0.0.1"
+  @version "0.1.0"
 
   def project do
     [app: :isn,

test/isn/ean13_test.exs

@@ -0,0 +1,19 @@
+defmodule Isn.EAN13Test do
+  use ExUnit.Case, async: true
+
+  @test_ean "022-035648348-1"
+
+  test "cast" do
+    assert Isn.EAN13.cast(@test_ean) == {:ok, @test_ean}
+    assert Isn.EAN13.cast(nil) == :error
+  end
+
+  test "load" do
+    assert Isn.EAN13.load(@test_ean) == {:ok, @test_ean}
+  end
+
+  test "dump" do
+    assert Isn.EAN13.dump(@test_ean) == {:ok, @test_ean}
+  end
+end
+

test/isn/isbn_test.exs

@@ -0,0 +1,19 @@
+defmodule Isn.ISBNTest do
+  use ExUnit.Case, async: true
+
+  @test_isbn "1-937785-58-0"
+
+  test "cast" do
+    assert Isn.ISBN.cast(@test_isbn) == {:ok, @test_isbn}
+    assert Isn.ISBN.cast(nil) == :error
+  end
+
+  test "load" do
+    assert Isn.ISBN.load(@test_isbn) == {:ok, @test_isbn}
+  end
+
+  test "dump" do
+    assert Isn.ISBN.dump(@test_isbn) == {:ok, @test_isbn}
+  end
+end
+

test/isn/ismn13_test.exs

@@ -0,0 +1,18 @@
+defmodule Isn.ISMN13Test do
+  use ExUnit.Case, async: true
+
+  @test_ismn "979-0-060-11561-5"
+
+  test "cast" do
+    assert Isn.ISMN13.cast(@test_ismn) == {:ok, @test_ismn}
+    assert Isn.ISMN13.cast(nil) == :error
+  end
+
+  test "load" do
+    assert Isn.ISMN13.load(@test_ismn) == {:ok, @test_ismn}
+  end
+
+  test "dump" do
+    assert Isn.ISMN13.dump(@test_ismn) == {:ok, @test_ismn}
+  end
+end

test/isn/ismn_test.exs

@@ -0,0 +1,19 @@
+defmodule Isn.ISMNTest do
+  use ExUnit.Case, async: true
+
+  @test_ismn "M-060-11561-5"
+
+  test "cast" do
+    assert Isn.ISMN.cast(@test_ismn) == {:ok, @test_ismn}
+    assert Isn.ISMN.cast(nil) == :error
+  end
+
+  test "load" do
+    assert Isn.ISMN.load(@test_ismn) == {:ok, @test_ismn}
+  end
+
+  test "dump" do
+    assert Isn.ISMN.dump(@test_ismn) == {:ok, @test_ismn}
+  end
+end
+

test/isn/issn13_test.exs

@@ -0,0 +1,18 @@
+defmodule Isn.ISSN13Test do
+  use ExUnit.Case, async: true
+
+  @test_issn "977-1436-452-00-8"
+
+  test "cast" do
+    assert Isn.ISSN13.cast(@test_issn) == {:ok, @test_issn}
+    assert Isn.ISSN13.cast(nil) == :error
+  end
+
+  test "load" do
+    assert Isn.ISSN13.load(@test_issn) == {:ok, @test_issn}
+  end
+
+  test "dump" do
+    assert Isn.ISSN13.dump(@test_issn) == {:ok, @test_issn}
+  end
+end

test/isn/issn_test.exs

@@ -0,0 +1,19 @@
+defmodule Isn.ISSNTest do
+  use ExUnit.Case, async: true
+
+  @test_issn "1436-4522"
+
+  test "cast" do
+    assert Isn.ISSN.cast(@test_issn) == {:ok, @test_issn}
+    assert Isn.ISSN.cast(nil) == :error
+  end
+
+  test "load" do
+    assert Isn.ISSN.load(@test_issn) == {:ok, @test_issn}
+  end
+
+  test "dump" do
+    assert Isn.ISSN.dump(@test_issn) == {:ok, @test_issn}
+  end
+end
+

test/isn/upc_test.exs

@@ -0,0 +1,20 @@
+defmodule Isn.UPCTest do
+  use ExUnit.Case, async: true
+
+  @test_upc "220356483481"
+
+  test "cast" do
+    assert Isn.UPC.cast(@test_upc) == {:ok, @test_upc}
+    assert Isn.UPC.cast(nil) == :error
+  end
+
+  test "load" do
+    assert Isn.UPC.load(@test_upc) == {:ok, @test_upc}
+  end
+
+  test "dump" do
+    assert Isn.UPC.dump(@test_upc) == {:ok, @test_upc}
+  end
+end
+
+

test/isn_test.exs

@@ -1,4 +1,4 @@
-defmodule IsnExtensionTest do
+defmodule IsnTest do
   use ExUnit.Case, async: true
   import Isn.TestHelper
   alias Postgrex.Connection, as: P
@@ -6,7 +6,7 @@ defmodule IsnExtensionTest do
   setup do
     {:ok, pid} = P.start_link(
       database: "isn_test",
-      extensions: [{Isn.Extension, {}}])
+      extensions: [{Isn, {}}])
     {:ok, [pid: pid]}
   end