ValidatedStruct

ValidatedStruct is a library to define struct that come with built-in validation based on specs.

ValidatedStruct is a plugin for type struct.

Installation

If available in Hex, the package can be installed by adding validated_struct to your list of dependencies in mix.exs:

def deps do
  [
    {:validated_struct, "~> 0.0.3"}
  ]
end

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

Example

defmodule Money do
  use ValidatedStruct

  validatedstruct do
      field :amount, non_neg_integer()
      field :currency, :eur | :usd
  end
end

The above code generates functions called make and update that can be used to create and update structs with validation:

{:ok, money} = Money.make(amount: 10, currency: :eur)
{:ok, updated_money} = Money.update(acount: 11)

{:error, _} = Money.make(amount: 10, currency: :cad)
{:error, _} = Money.make(amount: "10", currency: :usd)

Fields in validated structs are always enforced.

Overview

• General Usage
• Adapting Validation
• Validation Return Types
• Type Resolution and Type Exporter
• Validated Types
• Compile-Time safe Constructors
• Macro Expansion explained
• Validation on Steroids

Hot code reloading in releases

ValidatedStruct heavily relies on debug information, which is usually stripped in production code.

You have to add strip_beams: [keep: ["Dbgi"]] in your release config in root > mix.exs > &project/0 > releases > <release_name>

Generators

There is a library, that adds stream data generators to validated struct. It can be found at hex.pm.