accodeing/fortnox-api

# frozen_string_literal: true

module Matchers
  module Type
    def have_nullable(attribute, valid_value, invalid_value, default_value)
      HaveNullableMatcher.new(attribute, valid_value, invalid_value, default_value)
    end

    class HaveNullableMatcher
      def initialize(attribute, valid_value, invalid_value, default_value)
        @attribute = attribute
        @valid_value = valid_value
        @invalid_value = invalid_value
        @default_value = default_value
        @failure_description = ''
      end

      def matches?(klass)
        @klass = klass

        accepts_nil? && accepts_valid_value? && defaults_invalid_value?
      end

      def description
        "have nullable attribute #{@attribute.inspect}"
      end

      def failure_message
        "Expected class to have nullable attribute #{@attribute.inspect}" << @failure_description
      end

      private

      def accepts_nil?
        @klass.new(@attribute => nil)
      end

      def accepts_valid_value?
        model = @klass.new(@attribute => @valid_value)
        model.send(@attribute) == @valid_value
      end

      def defaults_invalid_value?
        model = @klass.new(@attribute => @invalid_value)
        value = model.send(@attribute)
        return true if value == @default_value

        @failure_description << " (Expected #{@invalid_value.inspect} to default to " \
                                "#{@default_value.inspect}), but got #{value.inspect}"
        false
      end
    end
  end
end