DryValidation

Provides a DSL to define complex validation schemas, with the ability to cast values, define custom validation rules and much more.

Installation

def deps do
  [
    {:dry_validation, "~> 1.0"}
  ]
end

Example

  require DryValidation
  alias DryValidation.Types
  
  schema = DryValidation.schema do
    required :name, Types.String
    optional :age, Types.Integer
  end
  
  input_data = %{"name" => "John", "age" => "15"}
  {:ok, output_data} = DryValidation.Validator.validate(schema, input_data)
  assert output_data == %{"name" => "John", "age" => 15}
  
  input_data = %{"name" => 15, "age" => "nonsense"}
  {:error, error} = DryValidation.Validator.validate(schema, input_data)
  assert error == %{
    "name" => "15 is not a valid type; Expected type is DryValidation.Types.String",
    "age" => ~s("nonsense" is not a valid type; Expected type is DryValidation.Types.Integer)
  }

Complex schemas can be crafted using the methods - required, optional, map and map_list. With the use the provided DryValidation.Types, requirements can be set and also cast values when possible.

## Available Types Type | Description ------------- | ------------- DryValidation.Types.String | Expects a string type "some text". Will try to cast the value into a string (1001 = "1001"). DryValidation.Types.Bool | Expects a boolean type [true/false]. Will cast the strings "true"/"false" to real booleans DryValidation.Types.Date | Expects a date type ~U[2023-01-20]. Will try to cast the value into a a date using Date.from_iso8601. DryValidation.Types.Float | Expects a float type [15.51]. Will try to cast a string to a float ("15.5" = 15.5). DryValidation.Types.Integer | Expects an integer type [101]. Will try to cast a string to an integer ("100" = 100). It'll fail the cast if the string is a float. DryValidation.Types.Func | Custom rules can be build using this, see the module docs. Example is the DryValidation.Types.Integer.greater_than(5) rule. DryValidation.Types.List | Expects a list. Can have the list type set to one of the above, including a Func. DryValidation.Types.Any | Accepts any value and will do no casting. Usually not used as the type can just be omitted when using optional and required

## Advanced example

  schema = DryValidation.schema do
    required :name, Types.String
    required :age, Types.Integer.greater_than(18)
    required :type, Types.Func.equal("users")
    optional :pets, Types.Func.member_of(["dog", "cat", "bird"])
    optional :favourite_numbers, Types.List.type(Types.Integer)

    map_list :cars do
      required :make, Types.String
      required :cc, Types.Integer
    end

    map :house, optional: true do
      required :address, Types.String
    end
  end

  input_data = %{
    "name" => "Jon Snow",
    "age" => 42,
    "type" => "users",
    "pet" => "dog",
    "favourite_numbers" => [],
    "cars" => [
      %{"make" => "AUDI", "cc" => 3000},
      %{"make" => "BMW", "cc" => 2000},
    ],
    "house" => %{
      "address" => "Church Road"
    }
  }
  {:ok, _output_data} = DryValidation.Validator.validate(schema, input_data)

Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/dry_validation.