Merge branch 'ajk-offset-pagination' into 'master'

Add offset_pagination resolver helper

See merge request gitlab-org/gitlab!48493

app/graphql/resolvers/base_resolver.rb

@@ -109,6 +109,10 @@ module Resolvers
       [args[:iid], args[:iids]].any? ? 0 : 0.01
     end
 
+    def offset_pagination(relation)
+      ::Gitlab::Graphql::Pagination::OffsetActiveRecordRelationConnection.new(relation)
+    end
+
     override :object
     def object
       super.tap do |obj|

app/graphql/resolvers/board_list_issues_resolver.rb

@@ -16,7 +16,7 @@ module Resolvers
       filter_params = issue_filters(args[:filters]).merge(board_id: list.board.id, id: list.id)
       service = ::Boards::Issues::ListService.new(list.board.resource_parent, context[:current_user], filter_params)
 
-      Gitlab::Graphql::Pagination::OffsetActiveRecordRelationConnection.new(service.execute)
+      offset_pagination(service.execute)
     end
 
     # https://gitlab.com/gitlab-org/gitlab/-/issues/235681

app/graphql/resolvers/board_lists_resolver.rb

@@ -27,7 +27,7 @@ module Resolvers
         List.preload_preferences_for_user(lists, context[:current_user])
       end
 
-      Gitlab::Graphql::Pagination::OffsetActiveRecordRelationConnection.new(lists)
+      offset_pagination(lists)
     end
 
     private

app/graphql/resolvers/issues_resolver.rb

@@ -24,7 +24,7 @@ module Resolvers
       if non_stable_cursor_sort?(args[:sort])
         # Certain complex sorts are not supported by the stable cursor pagination yet.
         # In these cases, we use offset pagination, so we return the correct connection.
-        Gitlab::Graphql::Pagination::OffsetActiveRecordRelationConnection.new(issues)
+        offset_pagination(issues)
       else
         issues
       end

doc/development/graphql_guide/pagination.md

@@ -86,6 +86,20 @@ However, there are some cases where we have to use the offset
 pagination connection, `OffsetActiveRecordRelationConnection`, such as when
 sorting by label priority in issues, due to the complexity of the sort.
 
+If you return a relation from a resolver that is not suitable for keyset
+pagination (due to the sort order for example), then you can use the
+`BaseResolver#offset_pagination` method to wrap the relation in the correct
+connection type. For example:
+
+```ruby
+def resolve(**args)
+  result = Finder.new(object, current_user, args).execute
+  result = offset_pagination(result) if needs_offset?(args[:sort])
+
+  result
+end
+```
+
 ### Keyset pagination
 
 The keyset pagination implementation is a subclass of `GraphQL::Pagination::ActiveRecordRelationConnection`,
@@ -225,7 +239,7 @@ instead of an `ActiveRecord::Relation`:
       if non_stable_cursor_sort?(args[:sort])
         # Certain complex sorts are not supported by the stable cursor pagination yet.
         # In these cases, we use offset pagination, so we return the correct connection.
-        Gitlab::Graphql::Pagination::OffsetActiveRecordRelationConnection.new(issues)
+        offset_pagination(issues)
       else
         issues
       end

ee/app/graphql/resolvers/iterations_resolver.rb

@@ -40,7 +40,7 @@ module Resolvers
       # Necessary for scopedPath computation in IterationPresenter
       context[:parent_object] = parent
 
-      Gitlab::Graphql::Pagination::OffsetActiveRecordRelationConnection.new(iterations)
+      offset_pagination(iterations)
     end
 
     private

spec/graphql/resolvers/base_resolver_spec.rb

@@ -273,4 +273,12 @@ RSpec.describe Resolvers::BaseResolver do
       end
     end
   end
+
+  describe '#offset_pagination' do
+    let(:instance) { resolver_instance(resolver) }
+
+    it 'is sugar for OffsetActiveRecordRelationConnection.new' do
+      expect(instance.offset_pagination(User.none)).to be_a(::Gitlab::Graphql::Pagination::OffsetActiveRecordRelationConnection)
+    end
+  end
 end