1 files changed, 195 insertions, 0 deletions
diff --git a/spec/services/design_management/delete_designs_service_spec.rb b/spec/services/design_management/delete_designs_service_spec.rb
new file mode 100644
index 00000000000..2c0c1570cb4
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+++ b/spec/services/design_management/delete_designs_service_spec.rb
@@ -0,0 +1,195 @@
+# frozen_string_literal: true
+require 'spec_helper'
+
+describe DesignManagement::DeleteDesignsService do
+  include DesignManagementTestHelpers
+
+  let_it_be(:project) { create(:project) }
+  let_it_be(:issue) { create(:issue, project: project) }
+  let_it_be(:user) { create(:user) }
+  let(:designs) { create_designs }
+
+  subject(:service) { described_class.new(project, user, issue: issue, designs: designs) }
+
+  # Defined as a method so that the reponse is not cached. We also construct
+  # a new service executor each time to avoid the intermediate cached values
+  # it constructs during its execution.
+  def run_service(delenda = nil)
+    service = described_class.new(project, user, issue: issue, designs: delenda || designs)
+    service.execute
+  end
+
+  let(:response) { run_service }
+
+  shared_examples 'a service error' do
+    it 'returns an error', :aggregate_failures do
+      expect(response).to include(status: :error)
+    end
+  end
+
+  shared_examples 'a top-level error' do
+    let(:expected_error) { StandardError }
+    it 'raises an en expected error', :aggregate_failures do
+      expect { run_service }.to raise_error(expected_error)
+    end
+  end
+
+  shared_examples 'a success' do
+    it 'returns successfully', :aggregate_failures do
+      expect(response).to include(status: :success)
+    end
+
+    it 'saves the user as the author' do
+      version = response[:version]
+
+      expect(version.author).to eq(user)
+    end
+  end
+
+  before do
+    enable_design_management(enabled)
+    project.add_developer(user)
+  end
+
+  describe "#execute" do
+    context "when the feature is not available" do
+      let(:enabled) { false }
+
+      it_behaves_like "a service error"
+    end
+
+    context "when the feature is available" do
+      let(:enabled) { true }
+
+      it 'is able to delete designs' do
+        expect(service.send(:can_delete_designs?)).to be true
+      end
+
+      context 'no designs were passed' do
+        let(:designs) { [] }
+
+        it_behaves_like "a top-level error"
+
+        it 'does not log any events' do
+          counter = ::Gitlab::UsageDataCounters::DesignsCounter
+          expect { run_service rescue nil }.not_to change { counter.totals }
+        end
+      end
+
+      context 'one design is passed' do
+        before do
+          create_designs(2)
+        end
+
+        let!(:designs) { create_designs(1) }
+
+        it 'removes that design' do
+          expect { run_service }.to change { issue.designs.current.count }.from(3).to(2)
+        end
+
+        it 'logs a deletion event' do
+          counter = ::Gitlab::UsageDataCounters::DesignsCounter
+          expect { run_service }.to change { counter.read(:delete) }.by(1)
+        end
+
+        it 'informs the new-version-worker' do
+          expect(::DesignManagement::NewVersionWorker).to receive(:perform_async).with(Integer)
+
+          run_service
+        end
+
+        it 'creates a new version' do
+          expect { run_service }.to change { DesignManagement::Version.where(issue: issue).count }.by(1)
+        end
+
+        it 'returns the new version' do
+          version = response[:version]
+
+          expect(version).to eq(DesignManagement::Version.for_issue(issue).ordered.first)
+        end
+
+        it_behaves_like "a success"
+
+        it 'removes the design from the current design list' do
+          run_service
+
+          expect(issue.designs.current).not_to include(designs.first)
+        end
+
+        it 'marks the design as deleted' do
+          expect { run_service }
+            .to change { designs.first.deleted? }.from(false).to(true)
+        end
+      end
+
+      context 'more than one design is passed' do
+        before do
+          create_designs(1)
+        end
+
+        let!(:designs) { create_designs(2) }
+
+        it 'removes those designs' do
+          expect { run_service }
+            .to change { issue.designs.current.count }.from(3).to(1)
+        end
+
+        it 'logs the correct number of deletion events' do
+          counter = ::Gitlab::UsageDataCounters::DesignsCounter
+          expect { run_service }.to change { counter.read(:delete) }.by(2)
+        end
+
+        it_behaves_like "a success"
+
+        context 'after executing the service' do
+          let(:deleted_designs) { designs.map(&:reset) }
+
+          let!(:version) { run_service[:version] }
+
+          it 'removes the removed designs from the current design list' do
+            expect(issue.designs.current).not_to include(*deleted_designs)
+          end
+
+          it 'does not make the designs impossible to find' do
+            expect(issue.designs).to include(*deleted_designs)
+          end
+
+          it 'associates the new version with all the designs' do
+            current_versions = deleted_designs.map { |d| d.most_recent_action.version }
+            expect(current_versions).to all(eq version)
+          end
+
+          it 'marks all deleted designs as deleted' do
+            expect(deleted_designs).to all(be_deleted)
+          end
+
+          it 'marks all deleted designs with the same deletion version' do
+            expect(deleted_designs.map { |d| d.most_recent_action.version_id }.uniq)
+              .to have_attributes(size: 1)
+          end
+        end
+      end
+
+      describe 'scalability' do
+        before do
+          run_service(create_designs(1)) # ensure project, issue, etc are created
+        end
+
+        it 'makes the same number of DB requests for one design as for several' do
+          one = create_designs(1)
+          many = create_designs(5)
+
+          baseline = ActiveRecord::QueryRecorder.new { run_service(one) }
+
+          expect { run_service(many) }.not_to exceed_query_limit(baseline)
+        end
+      end
+    end
+  end
+
+  private
+
+  def create_designs(how_many = 2)
+    create_list(:design, how_many, :with_lfs_file, issue: issue)
+  end
+end