def check_ancestry_integrity! options = {}
      parents = {}
      exceptions = [] if options[:report] == :list

      unscoped_where do |scope|
        # For each node ...
        scope.find_each do |node|
          begin
            # ... check validity of ancestry column
            if !node.valid? and !node.errors[node.class.ancestry_column].blank?
              raise Ancestry::AncestryIntegrityException.new("Invalid format for ancestry column of node #{node.id}: #{node.read_attribute node.ancestry_column}.")
            end
            # ... check that all ancestors exist
            node.ancestor_ids.each do |ancestor_id|
              unless exists? ancestor_id
                raise Ancestry::AncestryIntegrityException.new("Reference to non-existent node in node #{node.id}: #{ancestor_id}.")
              end
            end
            # ... check that all node parents are consistent with values observed earlier
            node.path_ids.zip([nil] + node.path_ids).each do |node_id, parent_id|
              parents[node_id] = parent_id unless parents.has_key? node_id
              unless parents[node_id] == parent_id
                raise Ancestry::AncestryIntegrityException.new("Conflicting parent id found in node #{node.id}: #{parent_id || 'nil'} for node #{node_id} while expecting #{parents[node_id] || 'nil'}")
              end
            end
          rescue Ancestry::AncestryIntegrityException => integrity_exception
            case options[:report]
              when :list then exceptions << integrity_exception
              when :echo then puts integrity_exception
              else raise integrity_exception
            end
          end
        end
      end
      exceptions if options[:report] == :list
    end
def check_ancestry_integrity! options = {}
      parents = {}
      exceptions = [] if options[:report] == :list

      unscoped_where do |scope|
        # For each node ...
        scope.find_each do |node|
          begin
            # ... check validity of ancestry column
            if !node.valid? and !node.errors[node.class.ancestry_column].blank?
              raise Ancestry::AncestryIntegrityException.new("Invalid format for ancestry column of node #{node.id}: #{node.read_attribute node.ancestry_column}.")
            end
            # ... check that all ancestors exist
            node.ancestor_ids.each do |ancestor_id|
              unless exists? ancestor_id
                raise Ancestry::AncestryIntegrityException.new("Reference to non-existent node in node #{node.id}: #{ancestor_id}.")
              end
            end
            # ... check that all node parents are consistent with values observed earlier
            node.path_ids.zip([nil] + node.path_ids).each do |node_id, parent_id|
              parents[node_id] = parent_id unless parents.has_key? node_id
              unless parents[node_id] == parent_id
                raise Ancestry::AncestryIntegrityException.new("Conflicting parent id found in node #{node.id}: #{parent_id || 'nil'} for node #{node_id} while expecting #{parents[node_id] || 'nil'}")
              end
            end
          rescue Ancestry::AncestryIntegrityException => integrity_exception
            case options[:report]
              when :list then exceptions << integrity_exception
              when :echo then puts integrity_exception
              else raise integrity_exception
            end
          end
        end
      end
      exceptions if options[:report] == :list
    end
Integrity checking