BulkImports: Avoid exception in EpicsPipeline when there's no Group

ee/lib/ee/bulk_imports/pipeline/epic_base.rb

@@ -9,13 +9,15 @@ module EE
         def initialize(context)
           super(context)
 
+          return if context.group.blank?
+
           @epic_iids = context.group.epics.order(iid: :desc).pluck(:iid) # rubocop: disable CodeReuse/ActiveRecord
 
           set_next_epic
         end
 
         def run
-          return skip!('Skipping because group has no epics') if current_epic_iid.blank?
+          return skip!(skip_reason) if current_epic_iid.blank?
 
           super
         end
@@ -43,6 +45,14 @@ module EE
         def current_epic_iid
           context.extra[:epic_iid]
         end
+
+        def skip_reason
+          if context.group.blank?
+            'Skipping because bulk import has no group'
+          else
+            'Skipping because group has no epics'
+          end
+        end
       end
     end
   end

ee/spec/lib/ee/bulk_imports/pipeline/epic_base_spec.rb

@@ -3,11 +3,6 @@
 require 'spec_helper'
 
 RSpec.describe EE::BulkImports::Pipeline::EpicBase do
-  let_it_be(:group) { create(:group) }
-  let_it_be(:entity) { create(:bulk_import_entity, group: group) }
-  let_it_be(:pipeline_tracker) { create(:bulk_import_tracker, entity: entity) }
-  let_it_be(:context) { BulkImports::Pipeline::Context.new(pipeline_tracker) }
-
   let(:pipeline_class) do
     Class.new(EE::BulkImports::Pipeline::EpicBase) do
       def extract(_)
@@ -30,6 +25,33 @@ RSpec.describe EE::BulkImports::Pipeline::EpicBase do
     stub_const('MyPipeline', pipeline_class)
   end
 
+  context 'when the group was not imported' do
+    let_it_be(:pipeline_tracker) { create(:bulk_import_tracker) }
+    let_it_be(:context) { BulkImports::Pipeline::Context.new(pipeline_tracker) }
+
+    it 'skips the pipeline' do
+      expect_next_instance_of(Gitlab::Import::Logger) do |logger|
+        expect(logger).to receive(:warn)
+          .with(
+            bulk_import_id: pipeline_tracker.entity.bulk_import.id,
+            bulk_import_entity_id: pipeline_tracker.entity.id,
+            bulk_import_entity_type: pipeline_tracker.entity.source_type,
+            message: 'Skipping because bulk import has no group',
+            pipeline_class: 'MyPipeline'
+          )
+      end
+
+      expect { subject.run }
+        .to change(pipeline_tracker, :status_name).to(:skipped)
+    end
+  end
+
+  context 'when the group was already imported' do
+    let_it_be(:group) { create(:group) }
+    let_it_be(:entity) { create(:bulk_import_entity, group: group) }
+    let_it_be(:pipeline_tracker) { create(:bulk_import_tracker, entity: entity) }
+    let_it_be(:context) { BulkImports::Pipeline::Context.new(pipeline_tracker) }
+
     context 'when the group has no epics' do
       it 'skips the pipeline' do
         expect_next_instance_of(Gitlab::Import::Logger) do |logger|
@@ -131,4 +153,5 @@ RSpec.describe EE::BulkImports::Pipeline::EpicBase do
         subject.run
       end
     end
+  end
 end