1 files changed, 36 insertions, 0 deletions
diff --git a/spec/lib/gitlab/background_migration/replace_blocked_by_links_spec.rb b/spec/lib/gitlab/background_migration/replace_blocked_by_links_spec.rb
new file mode 100644
index 00000000000..fa4f2d1fd88
--- /dev/null
+++ b/spec/lib/gitlab/background_migration/replace_blocked_by_links_spec.rb
@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::BackgroundMigration::ReplaceBlockedByLinks, schema: 20201015073808 do
+  let(:namespace) { table(:namespaces).create!(name: 'gitlab', path: 'gitlab-org') }
+  let(:project) { table(:projects).create!(namespace_id: namespace.id, name: 'gitlab') }
+  let(:issue1) { table(:issues).create!(project_id: project.id, title: 'a') }
+  let(:issue2) { table(:issues).create!(project_id: project.id, title: 'b') }
+  let(:issue3) { table(:issues).create!(project_id: project.id, title: 'c') }
+  let(:issue_links) { table(:issue_links) }
+  let!(:blocks_link) { issue_links.create!(source_id: issue1.id, target_id: issue2.id, link_type: 1) }
+  let!(:bidirectional_link) { issue_links.create!(source_id: issue2.id, target_id: issue1.id, link_type: 2) }
+  let!(:blocked_link) { issue_links.create!(source_id: issue1.id, target_id: issue3.id, link_type: 2) }
+
+  subject { described_class.new.perform(issue_links.minimum(:id), issue_links.maximum(:id)) }
+
+  it 'deletes issue links where opposite relation already exists' do
+    expect { subject }.to change { issue_links.count }.by(-1)
+  end
+
+  it 'ignores issue links other than blocked_by' do
+    subject
+
+    expect(blocks_link.reload.link_type).to eq(1)
+  end
+
+  it 'updates blocked_by issue links' do
+    subject
+
+    link = blocked_link.reload
+    expect(link.link_type).to eq(1)
+    expect(link.source_id).to eq(issue3.id)
+    expect(link.target_id).to eq(issue1.id)
+  end
+end