[Issue sorting on board] Addressing review issues

app/models/concerns/relative_positioning.rb

@@ -114,6 +114,13 @@ module RelativePositioning
 
   private
 
+  # This method takes two integer values (positions) and
+  # calculates some random position between them. The range is huge as
+  # the maximum integer value is 2147483647. Ideally, the calculated value would be
+  # exactly between those terminating values, but this will introduce possibility of a race condition
+  # so two or more issues can get the same value, we want to avoid that and we also want to avoid
+  # using a lock here. If we have two issues with distance more than one thousand, we are OK.
+  # Given the huge range of possible values that integer can fit we shoud never face a problem.
   def position_between(pos_before, pos_after)
     pos_before ||= MIN_POSITION
     pos_after ||= MAX_POSITION

app/services/boards/issues/move_service.rb

@@ -68,11 +68,9 @@ module Boards
       end
 
       def move_between_iids
-        move_after_iid = params[:move_after_iid]
-        move_before_iid = params[:move_before_iid]
-        return unless move_after_iid || move_before_iid
+        return unless params[:move_after_iid] || params[:move_before_iid]
 
-        [move_after_iid, move_before_iid]
+        [params[:move_after_iid], params[:move_before_iid]]
       end
     end
   end

spec/lib/gitlab/import_export/safe_model_attributes.yml

@@ -21,6 +21,7 @@ Issue:
 - milestone_id
 - weight
 - time_estimate
+- relative_position
 Event:
 - id
 - target_type

spec/services/boards/issues/list_service_spec.rb

@@ -43,32 +43,6 @@ describe Boards::Issues::ListService, services: true do
       described_class.new(project, user, params).execute
     end
 
-    context 'sets default order to priority' do
-      it 'returns opened issues when list id is missing' do
-        params = { board_id: board.id }
-
-        issues = described_class.new(project, user, params).execute
-
-        expect(issues).to eq [opened_issue2, reopened_issue1, opened_issue1]
-      end
-
-      it 'returns closed issues when listing issues from Done' do
-        params = { board_id: board.id, id: done.id }
-
-        issues = described_class.new(project, user, params).execute
-
-        expect(issues).to eq [closed_issue4, closed_issue2, closed_issue3, closed_issue1]
-      end
-
-      it 'returns opened issues that have label list applied when listing issues from a label list' do
-        params = { board_id: board.id, id: list1.id }
-
-        issues = described_class.new(project, user, params).execute
-
-        expect(issues).to eq [list1_issue3, list1_issue1, list1_issue2]
-      end
-    end
-
     context 'with list that does not belong to the board' do
       it 'raises an error' do
         list = create(:list)

spec/services/boards/issues/move_service_spec.rb

@@ -94,9 +94,9 @@ describe Boards::Issues::MoveService, services: true do
       end
 
       it 'sorts issues' do
-        issue.move_between(issue1, issue2)
+        issue.move_between!(issue1, issue2)
 
-        params.merge! move_after_iid: issue1.iid, move_before_iid: issue2.iid
+        params.merge! move_after_iid: issue.iid, move_before_iid: issue2.iid
 
         described_class.new(project, user, params).execute(issue1)