Better group support notes-related code

Updates notes-related services and rendering so this code can be
easily used for group-scoped resources (specifically Epics).

Related to gitlab-ee!5205

3 files changed, 51 insertions, 20 deletions

diff --git a/lib/banzai/cross_project_reference.rb b/lib/banzai/cross_project_reference.rb
index d8fb7705b2a..3f1e95d4cc0 100644
--- a/lib/banzai/cross_project_reference.rb
+++ b/lib/banzai/cross_project_reference.rb
@@ -4,7 +4,7 @@ module Banzai
   module CrossProjectReference
     # Given a cross-project reference string, get the Project record
     #
-    # Defaults to value of `context[:project]` if:
+    # Defaults to value of `context[:project]`, or `context[:group]` if:
     # * No reference is given OR
     # * Reference given doesn't exist
     #
@@ -12,7 +12,7 @@ module Banzai
     #
     # Returns a Project, or nil if the reference can't be found
     def parent_from_ref(ref)
-      return context[:project] unless ref
+      return context[:project] || context[:group] unless ref
 
       Project.find_by_full_path(ref)
     end
diff --git a/lib/banzai/filter/abstract_reference_filter.rb b/lib/banzai/filter/abstract_reference_filter.rb
index c3a03f13306..6efaed7e624 100644
--- a/lib/banzai/filter/abstract_reference_filter.rb
+++ b/lib/banzai/filter/abstract_reference_filter.rb
@@ -196,13 +196,15 @@ module Banzai
         end
       end
 
-      def data_attributes_for(text, project, object, link_content: false, link_reference: false)
+      def data_attributes_for(text, parent, object, link_content: false, link_reference: false)
+        object_parent_type = parent.is_a?(Group) ? :group : :project
+
         data_attribute(
-          original:       text,
-          link:           link_content,
-          link_reference: link_reference,
-          project:        project.id,
-          object_sym =>   object.id
+          original:             text,
+          link:                 link_content,
+          link_reference:       link_reference,
+          object_parent_type => parent.id,
+          object_sym =>         object.id
         )
       end
 
@@ -337,6 +339,12 @@ module Banzai
       def parent
         parent_type == :project ? project : group
       end
+
+      def full_group_path(group_ref)
+        return current_parent_path unless group_ref
+
+        group_ref
+      end
     end
   end
 end
diff --git a/lib/banzai/filter/label_reference_filter.rb b/lib/banzai/filter/label_reference_filter.rb
index faa5b344e6f..1cbada818fb 100644
--- a/lib/banzai/filter/label_reference_filter.rb
+++ b/lib/banzai/filter/label_reference_filter.rb
@@ -32,16 +32,25 @@ module Banzai
         end
       end
 
-      def find_label(project_ref, label_id, label_name)
-        project = parent_from_ref(project_ref)
-        return unless project
+      def find_label(parent_ref, label_id, label_name)
+        parent = parent_from_ref(parent_ref)
+        return unless parent
 
         label_params = label_params(label_id, label_name)
-        find_labels(project).find_by(label_params)
+        find_labels(parent).find_by(label_params)
       end
 
-      def find_labels(project)
-        LabelsFinder.new(nil, project_id: project.id, include_ancestor_groups: true).execute(skip_authorization: true)
+      def find_labels(parent)
+        params = if parent.is_a?(Group)
+                   { group_id: parent.id,
+                     include_ancestor_groups: true,
+                     only_group_labels: true }
+                 else
+                   { project_id: parent.id,
+                     include_ancestor_groups: true }
+                 end
+
+        LabelsFinder.new(nil, params).execute(skip_authorization: true)
       end
 
       # Parameters to pass to `Label.find_by` based on the given arguments
@@ -59,20 +68,34 @@ module Banzai
         end
       end
 
-      def url_for_object(label, project)
+      def url_for_object(label, parent)
         h = Gitlab::Routing.url_helpers
-        h.project_issues_url(project, label_name: label.name, only_path: context[:only_path])
+
+        if parent.is_a?(Project)
+          h.project_issues_url(parent, label_name: label.name, only_path: context[:only_path])
+        elsif context[:label_url_method]
+          h.public_send(context[:label_url_method], parent, label_name: label.name, only_path: context[:only_path]) # rubocop:disable GitlabSecurity/PublicSend
+        end
       end
 
       def object_link_text(object, matches)
-        project_path     = full_project_path(matches[:namespace], matches[:project])
-        project_from_ref = from_ref_cached(project_path)
-        reference        = project_from_ref.to_human_reference(project)
-        label_suffix     = " <i>in #{reference}</i>" if reference.present?
+        label_suffix = ''
+
+        if project || full_path_ref?(matches)
+          project_path    = full_project_path(matches[:namespace], matches[:project])
+          parent_from_ref = from_ref_cached(project_path)
+          reference       = parent_from_ref.to_human_reference(project || group)
+
+          label_suffix = " <i>in #{reference}</i>" if reference.present?
+        end
 
         LabelsHelper.render_colored_label(object, label_suffix)
       end
 
+      def full_path_ref?(matches)
+        matches[:namespace] && matches[:project]
+      end
+
       def unescape_html_entities(text)
         CGI.unescapeHTML(text.to_s)
       end