interactor_matcher.rb

require 'hanami/interactor'
require 'dry-matcher'

module Hanami::Interactor
  module Matcher
    SUCCESS_CASE = Dry::Matcher::Case.new(
      match: -> result { result.successful? },
      resolve: -> result { result.value }
    )

    FAILURE_CASE = Dry::Matcher::Case.new(
      match: -> result { result.failure? },
      resolve: -> result { result.value }
    )

    MatcherObject = Dry::Matcher.new(success: SUCCESS_CASE, failure: FAILURE_CASE)

    def call(*args, **kwargs, &block)
      @__result = ::Hanami::Interactor::Result.new
      _call(*args, **kwargs) { super }

      if block
        MatcherObject.(@__result, &block)
      else
        @__result
      end
    end
  end
end

module Hanami::Interactor::Interface
  include Hanami::Interactor::Matcher
end

class Operation
  include Hanami::Interactor
  expose :value

  def call(condition: true)
    if condition
      @value = 'hello'
    else
      @value = 'error'
      fail!
    end
  end
end

Operation.new.call(condition: true) do |m|
  m.success do |v|
    puts "Yay: #{v}"
  end

  m.failure do |v|
    puts "Boo: #{v}"
  end
end

Operation.new.call(condition: false) do |m|
  m.success do |v|
    puts "Yay: #{v}"
  end

  m.failure do |v|
    puts "Boo: #{v}"
  end
end