1 files changed, 90 insertions, 0 deletions

diff --git a/spec/workers/issues/rebalancing_worker_spec.rb b/spec/workers/issues/rebalancing_worker_spec.rb
new file mode 100644
index 00000000000..438edd85f66
--- /dev/null
+++ b/spec/workers/issues/rebalancing_worker_spec.rb
@@ -0,0 +1,90 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Issues::RebalancingWorker do
+  describe '#perform' do
+    let_it_be(:group) { create(:group) }
+    let_it_be(:project) { create(:project, group: group) }
+    let_it_be(:issue) { create(:issue, project: project) }
+
+    shared_examples 'running the worker' do
+      it 'runs an instance of Issues::RelativePositionRebalancingService' do
+        service = double(execute: nil)
+        service_param = arguments.second.present? ? kind_of(Project.id_in([project]).class) : kind_of(group&.all_projects.class)
+
+        expect(Issues::RelativePositionRebalancingService).to receive(:new).with(service_param).and_return(service)
+
+        described_class.new.perform(*arguments)
+      end
+
+      it 'anticipates there being too many concurent rebalances' do
+        service = double
+        service_param = arguments.second.present? ? kind_of(Project.id_in([project]).class) : kind_of(group&.all_projects.class)
+
+        allow(service).to receive(:execute).and_raise(Issues::RelativePositionRebalancingService::TooManyConcurrentRebalances)
+        expect(Issues::RelativePositionRebalancingService).to receive(:new).with(service_param).and_return(service)
+        expect(Gitlab::ErrorTracking).to receive(:log_exception).with(Issues::RelativePositionRebalancingService::TooManyConcurrentRebalances, include(project_id: arguments.second, root_namespace_id: arguments.third))
+
+        described_class.new.perform(*arguments)
+      end
+
+      it 'takes no action if the value is nil' do
+        expect(Issues::RelativePositionRebalancingService).not_to receive(:new)
+        expect(Gitlab::ErrorTracking).not_to receive(:log_exception)
+
+        described_class.new.perform # all arguments are nil
+      end
+    end
+
+    shared_examples 'safely handles non-existent ids' do
+      it 'anticipates the inability to find the issue' do
+        expect(Gitlab::ErrorTracking).to receive(:log_exception).with(ArgumentError, include(project_id: arguments.second, root_namespace_id: arguments.third))
+        expect(Issues::RelativePositionRebalancingService).not_to receive(:new)
+
+        described_class.new.perform(*arguments)
+      end
+    end
+
+    context 'without root_namespace param' do
+      it_behaves_like 'running the worker' do
+        let(:arguments) { [-1, project.id] }
+      end
+
+      it_behaves_like 'safely handles non-existent ids' do
+        let(:arguments) { [nil, -1] }
+      end
+
+      include_examples 'an idempotent worker' do
+        let(:job_args) { [-1, project.id] }
+      end
+
+      include_examples 'an idempotent worker' do
+        let(:job_args) { [nil, -1] }
+      end
+    end
+
+    context 'with root_namespace param' do
+      it_behaves_like 'running the worker' do
+        let(:arguments) { [nil, nil, group.id] }
+      end
+
+      it_behaves_like 'safely handles non-existent ids' do
+        let(:arguments) { [nil, nil, -1] }
+      end
+
+      include_examples 'an idempotent worker' do
+        let(:job_args) { [nil, nil, group.id] }
+      end
+
+      include_examples 'an idempotent worker' do
+        let(:job_args) { [nil, nil, -1] }
+      end
+    end
+  end
+
+  it 'has the `until_executed` deduplicate strategy' do
+    expect(described_class.get_deduplicate_strategy).to eq(:until_executed)
+    expect(described_class.get_deduplication_options).to include({ including_scheduled: true })
+  end
+end