Add information about epic to the csv export

- only include when the epics feature is available

doc/user/project/issues/csv_export.md

@@ -69,6 +69,8 @@ Data will be encoded with a comma as the column delimiter, with `"` used to quot
 | Labels | Title of any labels joined with a `,` |
 | Time Estimate | [Time estimate](../time_tracking.md#estimates) in seconds |
 | Time Spent | [Time spent](../time_tracking.md#time-spent) in seconds |
+| Epic ID | Id of the parent epic **(ULTIMATE)**, introduced in 12.7 |
+| Epic Title | Title of the parent epic **(ULTIMATE)**, introduced in 12.7 |
 
 ## Limitations
 

ee/app/services/issues/export_csv_service.rb

@@ -8,23 +8,26 @@ module Issues
     # Target attachment size before base64 encoding
     TARGET_FILESIZE = 15000000
 
-    def initialize(issues_relation)
+    attr_reader :project
+
+    def initialize(issues_relation, project)
       @issues = issues_relation
       @labels = @issues.labels_hash
+      @project = project
     end
 
     def csv_data
       csv_builder.render(TARGET_FILESIZE)
     end
 
-    def email(user, project)
+    def email(user)
       Notify.issues_csv_email(user, project, csv_data, csv_builder.status).deliver_now
     end
 
     # rubocop: disable CodeReuse/ActiveRecord
     def csv_builder
       @csv_builder ||=
-        CsvBuilder.new(@issues.preload(:author, :assignees, :timelogs), header_to_value_hash)
+        CsvBuilder.new(@issues.preload(:author, :assignees, :timelogs, :epic), header_to_value_hash)
     end
     # rubocop: enable CodeReuse/ActiveRecord
 
@@ -49,10 +52,25 @@ module Issues
        'Closed At (UTC)' => -> (issue) { issue.closed_at&.to_s(:csv) },
        'Milestone' => -> (issue) { issue.milestone&.title },
        'Weight' => -> (issue) { issue.weight },
-       'Labels' => -> (issue) { @labels[issue.id].sort.join(',').presence },
+       'Labels' => -> (issue) { issue_labels(issue) },
        'Time Estimate' => ->(issue) { issue.time_estimate.to_s(:csv) },
-       'Time Spent' => -> (issue) { issue.timelogs.map(&:time_spent).inject(0, :+)}
-      }
+       'Time Spent' => -> (issue) { issue_time_spent(issue) }
+      }.tap do |hash|
+        if project.group&.feature_available?(:epics)
+          hash['Epic ID'] = -> (issue) { issue.epic&.id }
+          hash['Epic Title'] = -> (issue) { issue.epic&.title }
+        end
+      end
+    end
+
+    def issue_labels(issue)
+      @labels[issue.id].sort.join(',').presence
     end
+
+    # rubocop: disable CodeReuse/ActiveRecord
+    def issue_time_spent(issue)
+      issue.timelogs.map(&:time_spent).sum
+    end
+    # rubocop: enable CodeReuse/ActiveRecord
   end
 end

ee/app/workers/export_csv_worker.rb

@@ -16,6 +16,6 @@ class ExportCsvWorker
 
     issues = IssuesFinder.new(@current_user, params).execute
 
-    Issues::ExportCsvService.new(issues).email(@current_user, @project)
+    Issues::ExportCsvService.new(issues, @project).email(@current_user)
   end
 end

ee/changelogs/unreleased/195177-epic-id-in-csv.yml

+---
+title: Add information about epic to Issue list csv export
+merge_request: 22662
+author:
+type: added

ee/spec/services/issues/export_csv_service_spec.rb

@@ -3,11 +3,12 @@
 require 'spec_helper'
 
 describe Issues::ExportCsvService do
-  let(:user) { create(:user) }
-  let(:project) { create(:project, :public) }
-  let!(:issue)  { create(:issue, project: project, author: user) }
+  let_it_be(:user) { create(:user) }
+  let(:group) { create(:group) }
+  let(:project) { create(:project, :public, group: group) }
+  let!(:issue) { create(:issue, project: project, author: user) }
   let!(:bad_issue) { create(:issue, project: project, author: user) }
-  let(:subject) { described_class.new(Issue.all) }
+  let(:subject) { described_class.new(Issue.all, project) }
 
   it 'renders csv to string' do
     expect(subject.csv_data).to be_a String
@@ -15,13 +16,13 @@ describe Issues::ExportCsvService do
 
   describe '#email' do
     it 'emails csv' do
-      expect { subject.email(user, project) }.to change(ActionMailer::Base.deliveries, :count)
+      expect { subject.email(user) }.to change(ActionMailer::Base.deliveries, :count)
     end
 
     it 'renders with a target filesize' do
       expect(subject.csv_builder).to receive(:render).with(described_class::TARGET_FILESIZE)
 
-      subject.email(user, project)
+      subject.email(user)
     end
   end
 
@@ -142,12 +143,42 @@ describe Issues::ExportCsvService do
       expect(csv[1]['Time Spent']).to eq '0'
     end
 
+    context 'handling epics' do
+      let(:epic) { create(:epic, group: group) }
+
+      before do
+        create(:epic_issue, issue: issue, epic: epic)
+      end
+
+      context 'with epics disabled' do
+        it 'does not include epics information' do
+          expect(csv[0]).not_to have_key('Epic ID')
+        end
+      end
+
+      context 'with epics enabled' do
+        before do
+          stub_licensed_features(epics: true)
+        end
+
+        specify 'epic ID' do
+          expect(csv[0]['Epic ID']).to eq(epic.id.to_s)
+          expect(csv[1]['Epic ID']).to be_nil
+        end
+
+        specify 'epic Title' do
+          expect(csv[0]['Epic Title']).to eq(epic.title)
+          expect(csv[1]['Epic Title']).to be_nil
+        end
+      end
+    end
+
     context 'with issues filtered by labels and project' do
       let(:subject) do
         described_class.new(
           IssuesFinder.new(user,
                            project_id: project.id,
-                           label_name: %w(Idea Feature)).execute)
+                           label_name: %w(Idea Feature)).execute, project)
       end
 
       it 'returns only filtered objects' do