1 files changed, 68 insertions, 0 deletions
diff --git a/app/graphql/resolvers/work_items/work_item_discussions_resolver.rb b/app/graphql/resolvers/work_items/work_item_discussions_resolver.rb
new file mode 100644
index 00000000000..b40d85e8003
--- /dev/null
+++ b/app/graphql/resolvers/work_items/work_item_discussions_resolver.rb
@@ -0,0 +1,68 @@
+# frozen_string_literal: true
+
+module Resolvers
+  module WorkItems
+    class WorkItemDiscussionsResolver < BaseResolver
+      include Gitlab::Graphql::Authorize::AuthorizeResource
+      extension Gitlab::Graphql::Extensions::ForwardOnlyExternallyPaginatedArrayExtension
+
+      authorize :read_work_item
+      authorizes_object!
+
+      # this resolver may be calling gitaly as part of parsing notes that contain commit references
+      calls_gitaly!
+
+      alias_method :notes_widget, :object
+
+      argument :filter, Types::WorkItems::NotesFilterTypeEnum,
+        required: false,
+        default_value: Types::WorkItems::NotesFilterTypeEnum.default_value,
+        description: 'Type of notes collection: ALL_NOTES, ONLY_COMMENTS, ONLY_ACTIVITY.'
+
+      type Types::Notes::DiscussionType.connection_type, null: true
+
+      def resolve(**args)
+        finder = Issuable::DiscussionsListService.new(current_user, work_item, params(args))
+
+        Gitlab::Graphql::ExternallyPaginatedArray.new(
+          finder.paginator.cursor_for_previous_page,
+          finder.paginator.cursor_for_next_page,
+          *finder.execute
+        )
+      end
+
+      def self.field_options
+        # we manage the pagination manually through external array, so opt out of the connection field extension
+        super.merge(connection: false)
+      end
+
+      def self.calculate_ext_conn_complexity
+        true
+      end
+
+      def self.complexity_multiplier(args)
+        0.05
+      end
+
+      private
+
+      def work_item
+        notes_widget.work_item
+      end
+      strong_memoize_attr :work_item
+
+      def params(args)
+        {
+          notes_filter: args[:filter],
+          cursor: args[:after],
+          per_page: self.class.nodes_limit(args, @field, context: context)
+        }
+      end
+
+      def self.nodes_limit(args, field, **kwargs)
+        page_size = field&.max_page_size || kwargs[:context]&.schema&.default_max_page_size
+        [args[:first], page_size].compact.min
+      end
+    end
+  end
+end