Add latest changes from gitlab-org/gitlab@13-2-stable-ee

1 files changed, 82 insertions, 0 deletions

diff --git a/lib/gitlab/graphql/loaders/issuable_loader.rb b/lib/gitlab/graphql/loaders/issuable_loader.rb
new file mode 100644
index 00000000000..1cc0fbe215f
--- /dev/null
+++ b/lib/gitlab/graphql/loaders/issuable_loader.rb
@@ -0,0 +1,82 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Graphql
+    module Loaders
+      class IssuableLoader
+        attr_reader :parent, :issuable_finder
+
+        BatchKey = Struct.new(:parent, :finder_class, :current_user)
+
+        def initialize(parent, issuable_finder)
+          @parent = parent
+          @issuable_finder = issuable_finder
+        end
+
+        def batching_find_all(&with_query)
+          if issuable_finder.params.keys == ['iids']
+            batch_load_issuables(issuable_finder.params[:iids], with_query)
+          else
+            post_process(find_all, with_query)
+          end
+        end
+
+        def find_all
+          issuable_finder.params[parent_param] = parent if parent
+
+          issuable_finder.execute
+        end
+
+        private
+
+        def parent_param
+          case parent
+          when Project
+            :project_id
+          when Group
+            :group_id
+          else
+            raise "Unexpected parent: #{parent.class}"
+          end
+        end
+
+        def post_process(query, with_query)
+          if with_query
+            with_query.call(query)
+          else
+            query
+          end
+        end
+
+        def batch_load_issuables(iids, with_query)
+          Array.wrap(iids).map { |iid| batch_load(iid, with_query) }
+        end
+
+        def batch_load(iid, with_query)
+          return if parent.nil?
+
+          BatchLoader::GraphQL
+            .for([parent_param, iid.to_s])
+            .batch(key: batch_key) do |params, loader, args|
+              batch_key = args[:key]
+              user = batch_key.current_user
+
+              params.group_by(&:first).each do |key, group|
+                iids = group.map(&:second).uniq
+                args = { key => batch_key.parent, iids: iids }
+                query = batch_key.finder_class.new(user, args).execute
+
+                post_process(query, with_query).each do |item|
+                  loader.call([key, item.iid.to_s], item)
+                end
+              end
+            end
+        end
+
+        def batch_key
+          BatchKey.new(parent, issuable_finder.class, issuable_finder.current_user)
+        end
+      end
+    end
+  end
+end