Remove adjacency checks

This removes an extra check on moving designs that fails frequently
in the presence of soft-deletes.

If we have `[a b (c) d e]` (where `c` is a deleted design, not visible
to the user), then an attempt to move `e -> (b,d)` will fail due to the
adjacency check, even though from the user's perspective, `b` and `d`
are adjacent.

As long as clients are sensible, this extra level of sanity checking
is not necessary.

app/models/design_management/design.rb

@@ -228,17 +228,6 @@ module DesignManagement
       project
     end
 
-    def immediately_before?(next_design)
-      return false if next_design.relative_position <= relative_position
-
-      interloper = self.class.on_issue(issue).where(
-        "relative_position <@ int4range(?, ?, '()')",
-        *[self, next_design].map(&:relative_position)
-      )
-
-      !interloper.exists?
-    end
-
     def notes_with_associations
       notes.includes(:author)
     end

app/services/design_management/move_designs_service.rb

@@ -16,7 +16,6 @@ module DesignManagement
       return error(:cannot_move) unless current_user.can?(:move_design, current_design)
       return error(:no_neighbors) unless neighbors.present?
       return error(:not_distinct) unless all_distinct?
-      return error(:not_adjacent) if any_in_gap?
       return error(:not_same_issue) unless all_same_issue?
 
       move_nulls_to_end
@@ -54,12 +53,6 @@ module DesignManagement
       ids.uniq.size == ids.size
     end
 
-    def any_in_gap?
-      return false unless previous_design&.relative_position && next_design&.relative_position
-
-      !previous_design.immediately_before?(next_design)
-    end
-
     def all_same_issue?
       issue.designs.id_in(ids).count == ids.size
     end

changelogs/unreleased/ajk-remove-adjacency-check.yml

+---
+title: Fix spurious not-adjacent error when moving designs
+merge_request: 53771
+author:
+type: fixed

spec/models/design_management/design_spec.rb

@@ -629,25 +629,4 @@ RSpec.describe DesignManagement::Design do
       end
     end
   end
-
-  describe '#immediately_before' do
-    let_it_be(:design) { create(:design, issue: issue, relative_position: 100) }
-    let_it_be(:next_design) { create(:design, issue: issue, relative_position: 200) }
-
-    it 'is true when there is no element positioned between this item and the next' do
-      expect(design.immediately_before?(next_design)).to be true
-    end
-
-    it 'is false when there is an element positioned between this item and the next' do
-      create(:design, issue: issue, relative_position: 150)
-
-      expect(design.immediately_before?(next_design)).to be false
-    end
-
-    it 'is false when the next design is to the left of this design' do
-      further_left = create(:design, issue: issue, relative_position: 50)
-
-      expect(design.immediately_before?(further_left)).to be false
-    end
-  end
 end

spec/services/design_management/move_designs_service_spec.rb

@@ -76,18 +76,6 @@ RSpec.describe DesignManagement::MoveDesignsService do
       end
     end
 
-    context 'the designs are not adjacent' do
-      let(:current_design) { designs.first }
-      let(:previous_design) { designs.second }
-      let(:next_design) { designs.third }
-
-      it 'raises not_adjacent' do
-        create(:design, issue: issue, relative_position: next_design.relative_position - 1)
-
-        expect(subject).to be_error.and(have_attributes(message: :not_adjacent))
-      end
-    end
-
     context 'moving a design with neighbours' do
       let(:current_design) { designs.first }
       let(:previous_design) { designs.second }