dried_interaction

DriedInteraction

DriedInteraction is a simple gem that helps you write interactors with input params validation.

Installation

Add this line to your application's Gemfile:

gem 'dried_interaction'

And then execute:

$ bundle

Or install it yourself as:

$ gem install dried_interaction

Usage

Setting up an interactor

For setting up an interactor you need to include DriedInteraction into your class. Then you can add contract for call method which will validate input params. By default interactor returns Dry::Matcher::ResultMatcher.

class PublishPost
  include DriedInteraction

  option :normalize_params, reader: :private, default: -> { PostParamsNormalize.new }
  option :post_repo, reader: :private, default: -> { PostRepo }
  option :notify, reader: :private, default: -> { PostNotify.new }

  contract do
    required(:user).filled(Dry.Types.Instance(User))
    required(:params).hash do
      required(:title).filled(:string)
      required(:content).filled(:string)
      optional(:public).filled(:bool)
    end
  end

  def call(user:, params:)
    normalized_params = yield normalize_params.call(params)
    post = yield save_post(normalized_params)
    notify.call(post)

    Success(post)
  end

  private

  def save_post(params)
    post = post_repo.new(params)
    post.save ? Success(post) : Failure('Error message')
  end
end

Contract options

You can pass to contract some options which will customize contract logic.

1. kind. Explains which type of validator you will use. Available values: simple (By default) and extended simple kind uses simple Dry::Schema.Params extended kind uses more complex Dry::Validation.Contract

  contract(kind: :simple) do ... end
  # or
  contract(kind: :extended) do ... end

1. mode. Explains how to handle contract validation errors. Available values: strict (By default) and soft strict mode raises exception when contract check fails. soft mode returns Failure monad with error info when contract check fails.

  contract(mode: :strict) do ... end # => raise DriedInteractionError
  # or
  contract(mode: :soft) do ... end # => returns Failure(DriedInteractionError)

Interactor calling

PublishPost.new.call({ user: user, params: params }) do |interactor|
  interactor.success do |post|
    # handle success
  end

  interactor.failure do |error|
    # handle failure
  end
end

When you use soft mode you can handle contract failure as divided failure case:

  PublishPost.new.call({ user: user, params: params }) do |interactor|
  interactor.success do |post|
    # handle success
  end

  interactor.failure(DriedInteractionError) do |error|
    #  handle contract validation error
  end

  interactor.failure do |error|
    # handle failure
  end
end

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

License

The gem is available as open source under the terms of the MIT License.