BulkImports: Associate mapped users to imported epics

Find epic author by email, if the author cannot be found use the
importer user as author.

Related to: https://gitlab.com/gitlab-org/gitlab/-/issues/298745

ee/changelogs/unreleased/kassio-bulkimports-epics-author.yml

+---
+title: 'BulkImports: Associate mapped users to imported epics'
+merge_request: 53296
+author:
+type: changed

ee/lib/ee/bulk_imports/groups/graphql/get_epics_query.rb

@@ -34,6 +34,9 @@ module EE
                     due_date_is_fixed: dueDateIsFixed
                     relative_position: relativePosition
                     confidential
+                    author {
+                      public_email: publicEmail
+                    }
                     parent {
                       iid
                     }

ee/lib/ee/bulk_imports/groups/transformers/epic_attributes_transformer.rb

@@ -23,7 +23,18 @@ module EE
           end
 
           def add_author_id(context, data)
-            data.merge('author_id' => context.current_user.id)
+            user = find_user_by_email(context, data.dig('author', 'public_email'))
+            author_id = user&.id || context.current_user.id
+
+            data
+              .merge('author_id' => author_id)
+              .except('author')
+          end
+
+          def find_user_by_email(context, email)
+            return if email.blank?
+
+            context.group.users.find_by_any_email(email, confirmed: true)
           end
 
           def add_parent(context, data)

ee/spec/lib/ee/bulk_imports/groups/graphql/get_epics_query_spec.rb

@@ -3,15 +3,15 @@
 require 'spec_helper'
 
 RSpec.describe EE::BulkImports::Groups::Graphql::GetEpicsQuery do
-  describe '#variables' do
-    let(:entity) { double(source_full_path: 'test', next_page_for: 'next_page', bulk_import: nil) }
-    let(:context) { BulkImports::Pipeline::Context.new(entity) }
+  it 'has a valid query' do
+    context = BulkImports::Pipeline::Context.new(create(:bulk_import_entity))
 
-    it 'returns query variables based on entity information' do
-      expected = { full_path: entity.source_full_path, cursor: entity.next_page_for }
+    result = GitlabSchema.execute(
+      described_class.to_s,
+      variables: described_class.variables(context)
+    ).to_h
 
-      expect(described_class.variables(context)).to eq(expected)
-    end
+    expect(result['errors']).to be_blank
   end
 
   describe '#data_path' do

ee/spec/lib/ee/bulk_imports/groups/transformers/epic_attributes_transformer_spec.rb

@@ -3,11 +3,11 @@
 require 'spec_helper'
 
 RSpec.describe EE::BulkImports::Groups::Transformers::EpicAttributesTransformer do
-  let(:user) { create(:user) }
-  let(:group) { create(:group) }
-  let(:bulk_import) { create(:bulk_import, user: user) }
-  let(:entity) { create(:bulk_import_entity, bulk_import: bulk_import, group: group) }
-  let(:context) { ::BulkImports::Pipeline::Context.new(entity) }
+  let_it_be(:importer_user) { create(:user) }
+  let_it_be(:group) { create(:group) }
+  let_it_be(:bulk_import) { create(:bulk_import, user: importer_user) }
+  let_it_be(:entity) { create(:bulk_import_entity, bulk_import: bulk_import, group: group) }
+  let_it_be(:context) { ::BulkImports::Pipeline::Context.new(entity) }
 
   describe '#transform' do
     it 'transforms the epic attributes' do
@@ -27,7 +27,7 @@ RSpec.describe EE::BulkImports::Groups::Transformers::EpicAttributesTransformer
         'relative_position' => 1073716855,
         'confidential' => false,
         'group_id' => group.id,
-        'author_id' => user.id,
+        'author_id' => importer_user.id,
         'parent' => nil,
         'children' => [],
         'labels' => []
@@ -67,7 +67,58 @@ RSpec.describe EE::BulkImports::Groups::Transformers::EpicAttributesTransformer
       end
     end
 
-    def epic_data(parent_iid: nil, children_iids: [], labels_titles: [])
+    context 'epic author' do
+      it 'finds user by primary confirmed email' do
+        member_user = create(:user, email: 'member@email.com')
+        group.add_owner(member_user)
+
+        data = epic_data(public_email: member_user.email)
+
+        transformed_data = subject.transform(context, data)
+
+        expect(transformed_data['author_id']).to eq(member_user.id)
+      end
+
+      it 'falls back to the importer user if primary email is not confirmed' do
+        member_user = create(:user, :unconfirmed, email: 'member@email.com')
+
+        group.add_owner(member_user)
+
+        data = epic_data(public_email: member_user.email)
+
+        transformed_data = subject.transform(context, data)
+
+        expect(transformed_data['author_id']).to eq(importer_user.id)
+      end
+
+      it 'findes user by secondary confirmed email' do
+        secondary_email = 'other@email.com'
+        member_user = create(:user, email: 'member@email.com')
+        create(:email, :confirmed, user: member_user, email: secondary_email)
+        group.add_owner(member_user)
+
+        data = epic_data(public_email: secondary_email)
+
+        transformed_data = subject.transform(context, data)
+
+        expect(transformed_data['author_id']).to eq(member_user.id)
+      end
+
+      it 'falls back to the importer user if secondary email is not confirmed' do
+        secondary_email = 'other@email.com'
+        member_user = create(:user, email: 'member@email.com')
+        create(:email, user: member_user, email: secondary_email)
+        group.add_owner(member_user)
+
+        data = epic_data(public_email: secondary_email)
+
+        transformed_data = subject.transform(context, data)
+
+        expect(transformed_data['author_id']).to eq(importer_user.id)
+      end
+    end
+
+    def epic_data(parent_iid: nil, children_iids: [], labels_titles: [], public_email: '')
       {
         'title' => 'title',
         'description' => 'description',
@@ -81,6 +132,9 @@ RSpec.describe EE::BulkImports::Groups::Transformers::EpicAttributesTransformer
         'due_date_is_fixed' => false,
         'relative_position' => 1073716855,
         'confidential' => false,
+        'author' => {
+          'public_email' => public_email
+        },
         'parent' => {
           'iid' => parent_iid
         },