module ActiveRecord
  class PredicateBuilder
    class ArrayHandler # :nodoc:
      def call(attribute, value)
        values = value.map { |x| x.is_a?(Base) ? x.id : x }
        ranges, values = values.partition { |v| v.is_a?(Range) }

        values_predicate = if values.include?(nil)
          values = values.compact

          case values.length
          when 0
            attribute.eq(nil)
          when 1
            attribute.eq(values.first).or(attribute.eq(nil))
          else
            attribute.in(values).or(attribute.eq(nil))
          end
        else
          attribute.in(values)
        end

        array_predicates = ranges.map { |range| attribute.in(range) }
        array_predicates << values_predicate
        array_predicates.inject { |composite, predicate| composite.or(predicate) }
      end
    end
  end
end

module ActiveRecord
  class PredicateBuilder
    class ArrayHandler # :nodoc:
      def call(attribute, value)
        values = value.map { |x| x.is_a?(Base) ? x.id : x }
        ranges, values = values.partition { |v| v.is_a?(Range) }
        nils, values = values.partition(&:nil?)

        values_predicate =
          case values.length
          when 0 then NullPredicate
          when 1 then attribute.eq(values.first)
          else attribute.in(values)
          end

        unless nils.empty?
          values_predicate = values_predicate.or(attribute.eq(nil))
        end

        array_predicates = ranges.map { |range| attribute.in(range) }
        array_predicates << values_predicate
        array_predicates.inject { |composite, predicate| composite.or(predicate) }
      end

      module NullPredicate
        def self.or(other)
          other
        end
      end
    end
  end
end

Refactor the handling of arrays in where predicates
Refactor the handling of arrays in where predicates

Simplifies the code slightly, isolates non-nil non-range values into a
single array, which will make it easier to do things like apply type
casting to them in the future.
