Reform monkey-patching

reform_ext.rb

require 'reform'
require 'reform/form/coercion'
require 'hashie/mash'

module Reform
  module DryTypes
    def property(name, type: nil, **options, &block)
      super(name, **options, &block).tap do
        if type
          # Tries to coerce value to the necessary type
          # Do not raise exception for the maximum coercions to be done
          define_method("#{name}=") do |value|
            value = type[value] rescue value
            super(value)
          end

          # Checks whether a type is valid
          validate do
            type[send(name)] rescue errors.add(name, :invalid)
          end
        end
      end
    end
  end

  module SubForm
    def property(name, **options, &block)
      if block || options[:form] || options[:twin]
        options[:populate_if_empty] = Hashie::Mash
      end

      super(name, options, &block)
    end

    def collection(name, **options, &block)
      if block || options[:form] || options[:twin]
        options[:populate_if_empty] = Hashie::Mash
      end

      super(name, options, &block)
    end
  end

  class Contract
    extend DryTypes
    extend SubForm

    # Break validation after the first type mismatch has occured
    #
    # Rescue from NoMethodError which can be risen when some validator
    # calls method expected for valid structure, but we failed to
    # coerce data to that structure.
    #
    def validate(*)
      super
    rescue TypeError, NoMethodError
      false
    end
  end
end