Decoder

Schema-first validation library for Elixir.

Usage examples can be found in the tests.

Installation

def deps do
  [
    {:decoder, "~> 0.1.0"}
  ]
end

Types

• map, record, tuple, list
• string, integer, boolean, any, nil, atom, literal
• union, optional

Options

• description - field error description
• extra_props - [dis]allow extra props
• strict - strict mode

Example:

assert {:ok, %{"name" => "Bruce Wayne", "age" => 30}} ===
 D.decode(
   D.map(
     %{
       "name" => D.string(),
       "age" => D.integer()
     },
     extra_props: false
   ),
   %{
     "name" => "Bruce Wayne",
     "age" => 30,
     "extra" => "extra"
   }
 )

Derives

Derives can sanitize, validate and format data.

• trim
• gt, gte, lt, lte
• min, max
• not_empty
• format

Examples:

assert {:ok, "Alfred Pennyworth"} = D.decode(D.string(derive: [:trim]), " Alfred Pennyworth ")

assert {:ok, DateTime.from_iso8601("2021-08-10T00:00:00Z") |> elem(1)} ==
             D.decode(D.string(derive: [{:format, "date-time"}]), "2021-08-10T00:00:00Z")

assert {:error, [%{message: "should be longer than 5"}]} =
             D.decode(D.string(derive: [:trim, {:min, 5}]), "f")

assert {:error, [%{message: "should not be empty"}]} =
             D.decode(D.string(derive: [:trim, :not_empty]), "  ")