Add more validation methods to Mayo.String

README.md

@@ -27,15 +27,23 @@ defmodule MyModule do
   require Mayo
 
   def call do
-    data = %{
-      username: "john",
+    Mayo.validate %{
+      username: "John",
       password: "123456"
+    }, %{
+      username: Mayo.Any.string |> Mayo.String.min(4),
+      password: Mayo.Any.string |> Mayo.String.min(6)
     }
+    # %{username: "John", password: "123456"}
 
-    Mayo.validate data, %{
+    Mayo.validate %{
+      username: "John",
+      password: "1234"
+    }, %{
       username: Mayo.Any.string |> Mayo.String.min(4),
-      password: Mayo.Any.string |> Mayo.String.min(6) |> Mayo.String.max(50)
+      password: Mayo.Any.string |> Mayo.String.min(6)
     }
+    # {:error, %Mayo.Error{type: "string.min", path: "password"}}
   end
 end
 ```

lib/mayo/string.ex

@@ -1,4 +1,10 @@
 defmodule Mayo.String do
+  # http://stackoverflow.com/a/13653180
+  @uuid_pattern ~r/^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/
+
+  # https://github.com/hapijs/joi/blob/master/lib/string.js#L312
+  @hex_pattern ~r/^[a-f0-9]+$/i
+
   @doc """
   Checks the minimum length of a string.
 
@@ -55,4 +61,101 @@ defmodule Mayo.String do
       }}
     end
   end
+
+  @doc """
+  Checks if the string is a valid UUID.
+
+      iex> Mayo.String.uuid("127862fc-3f59-47c4-9ccf-5d3bfbbe1271")
+      "127862fc-3f59-47c4-9ccf-5d3bfbbe1271"
+
+      iex> Mayo.String.uuid("test")
+      {:error, %Mayo.Error{type: "string.uuid"}}
+  """
+  def uuid(value) do
+    if String.match?(value, @uuid_pattern) do
+      value
+    else
+      {:error, %Mayo.Error{
+        type: "string.uuid"
+      }}
+    end
+  end
+
+  @doc """
+  Checks if the string only contains hex.
+
+      iex> Mayo.String.hex("a1b2")
+      "a1b2"
+
+      iex> Mayo.String.hex("lol")
+      {:error, %Mayo.Error{type: "string.hex"}}
+  """
+  def hex(value) do
+    if String.match?(value, @hex_pattern) do
+      value
+    else
+      {:error, %Mayo.Error{
+        type: "string.hex"
+      }}
+    end
+  end
+
+  @doc """
+  Checks if the string is a valid IPv4 or IPv6 address.
+
+      iex> Mayo.String.ip("210.59.230.150")
+      "210.59.230.150"
+
+      iex> Mayo.String.ip("2001:0DB8:02de:0000:0000:0000:0000:0e13")
+      "2001:0DB8:02de:0000:0000:0000:0000:0e13"
+
+      iex> Mayo.String.ip("test")
+      {:error, %Mayo.Error{type: "string.ip"}}
+  """
+  def ip(value) do
+    case value |> String.to_charlist |> :inet.parse_address do
+      {:ok, _} -> value
+      _ -> {:error, %Mayo.Error{
+        type: "string.ip"
+      }}
+    end
+  end
+
+  @doc """
+  Checks if the string matches the pattern.
+
+      iex> Mayo.String.match("abbbbbc", ~r/^ab+c$/)
+      "abbbbbc"
+
+      iex> Mayo.String.match("ac", ~r/^ab+c$/)
+      {:error, %Mayo.Error{type: "string.match"}}
+  """
+  def match(value, pattern) do
+    if String.match?(value, pattern) do
+      value
+    else
+      {:error, %Mayo.Error{
+        type: "string.match"
+      }}
+    end
+  end
+
+  @doc """
+  Checks if the string is a valid Luhn number. (Use [luhn_ex](https://github.com/ma2gedev/luhn_ex) library)
+
+      iex> Mayo.String.credit_card("378282246310005")
+      "378282246310005"
+
+      iex> Mayo.String.credit_card("123456789123456")
+      {:error, %Mayo.Error{type: "string.credit_card"}}
+  """
+  def credit_card(value) do
+    if Luhn.valid?(value) do
+      value
+    else
+      {:error, %Mayo.Error{
+        type: "string.credit_card"
+      }}
+    end
+  end
 end

mix.exs

@@ -23,7 +23,8 @@ defmodule Mayo.Mixfile do
   end
 
   defp deps do
-    [{:ex_doc, "~> 0.12", only: :docs},
+    [{:luhn, "~> 0.3"},
+     {:ex_doc, "~> 0.12", only: :docs},
      {:excoveralls, "~> 0.5", only: :test},
      {:inch_ex, "~> 0.5", only: :docs}]
   end

mix.lock

@@ -7,6 +7,7 @@
   "idna": {:hex, :idna, "1.2.0", "ac62ee99da068f43c50dc69acf700e03a62a348360126260e87f2b54eced86b2", [:rebar3], []},
   "inch_ex": {:hex, :inch_ex, "0.5.3", "39f11e96181ab7edc9c508a836b33b5d9a8ec0859f56886852db3d5708889ae7", [:mix], [{:poison, "~> 1.5 or ~> 2.0", [hex: :poison, optional: false]}]},
   "jsx": {:hex, :jsx, "2.6.2", "213721e058da0587a4bce3cc8a00ff6684ced229c8f9223245c6ff2c88fbaa5a", [:mix, :rebar], []},
+  "luhn": {:hex, :luhn, "0.3.1", "c8c38ee131378cff925fc9dad825fc85ecd9593fcec10dbba550d26bb1744af5", [:mix], []},
   "metrics": {:hex, :metrics, "1.0.1", "25f094dea2cda98213cecc3aeff09e940299d950904393b2a29d191c346a8486", [:rebar3], []},
   "mimerl": {:hex, :mimerl, "1.0.2", "993f9b0e084083405ed8252b99460c4f0563e41729ab42d9074fd5e52439be88", [:rebar3], []},
   "poison": {:hex, :poison, "2.2.0", "4763b69a8a77bd77d26f477d196428b741261a761257ff1cf92753a0d4d24a63", [:mix], []},