Alex Pooley
--- a/app/models/concerns/namespace/traversal.rb 0 → 100644
+++ b/app/models/concerns/namespace/traversal.rb 0 → 100644
+# We implement this in the database using Postgresql arrays, indexed by a
+# generalized inverted index (gin).
+class Namespace
+  module Traversal
+    extend ActiveSupport::Concern
+
+    included do
+      after_create :init_traversal_ids, if: :sync_traversal_ids?
+      after_update :sync_traversal_ids, if: -> { sync_traversal_ids? && saved_change_to_parent? }
+
+      scope :traversal_ids_contains, ->(ids) { where("traversal_ids @> (?)", ids) }
+      scope :traversal_ids_contained_by, ->(ids) { where("traversal_ids <@ (?)", ids) }
+    end
+
+    def sync_traversal_ids?
+      return false unless self.respond_to?(:traversal_ids)
--- a/app/models/concerns/namespace/traversal.rb 0 → 100644
+++ b/app/models/concerns/namespace/traversal.rb 0 → 100644
+    included do
+      after_create :init_traversal_ids, if: :sync_traversal_ids?
+      after_update :sync_traversal_ids, if: -> { sync_traversal_ids? && saved_change_to_parent? }
+
+      scope :traversal_ids_contains, ->(ids) { where("traversal_ids @> (?)", ids) }
+      scope :traversal_ids_contained_by, ->(ids) { where("traversal_ids <@ (?)", ids) }
+    end
+
+    def sync_traversal_ids?
+      return false unless self.respond_to?(:traversal_ids)
+
+      Feature.enabled?(:sync_traversal_ids, root_ancestor, default_enabled: false)
+    end
+
+    def linear_group_traversal?
+      return false unless self.respond_to?(:traversal_ids)
--- a/app/models/concerns/namespace/traversal.rb 0 → 100644
+++ b/app/models/concerns/namespace/traversal.rb 0 → 100644
+
+      scope :traversal_ids_contains, ->(ids) { where("traversal_ids @> (?)", ids) }
+      scope :traversal_ids_contained_by, ->(ids) { where("traversal_ids <@ (?)", ids) }
+    end
+
+    def sync_traversal_ids?
+      return false unless self.respond_to?(:traversal_ids)
+
+      Feature.enabled?(:sync_traversal_ids, root_ancestor, default_enabled: false)
+    end
+
+    def linear_group_traversal?
+      return false unless self.respond_to?(:traversal_ids)
+      return false if traversal_ids.blank?
+
+      Feature.enabled?(:linear_groups, root_ancestor, default_enabled: false)
--- a/app/models/concerns/namespace/traversal.rb 0 → 100644
+++ b/app/models/concerns/namespace/traversal.rb 0 → 100644
+
+      skope = without_sti_condition
+
+      if top
+        skope = skope.traversal_ids_contains(latest_traversal_ids(top))
+      end
+
+      if bottom
+        skope = skope.traversal_ids_contained_by(latest_traversal_ids(bottom))
+      end
+
+      # The original `with_depth` attribute in ObjectHierarchy increments as you
+      # walk away from the "base" namespace. This direction changes depending on
+      # if you are walking up the ancestors or down the descendants.
+      if hierarchy_order
+        depth_sql = "ABS(array_length((#{latest_traversal_ids.to_sql}), 1) - array_length(traversal_ids, 1))"
--- a/spec/helpers/groups_helper_spec.rb
+++ b/spec/helpers/groups_helper_spec.rb
-      end

-      it 'has the correct help text with correct ancestor links' do
-        expect(subject).to match(possible_help_texts[help_text])
-        expect(subject).to match(possible_linked_ancestors[linked_ancestor].name) unless help_text == :default_help
+        with_them do
+          before do
+            root_group.add_owner(root_owner)
+            subgroup.add_owner(sub_owner)
+            sub_subgroup.add_owner(sub_sub_owner)
+
+            root_group.update_column(:share_with_group_lock, true) if root_share_with_group_locked
+            subgroup.update_column(:share_with_group_lock, true) if subgroup_share_with_group_locked
+            sub_subgroup.update_column(:share_with_group_lock, true) if sub_subgroup_share_with_group_locked
+
+            allow(helper).to receive(:current_user).and_return(users[current_user])