1 files changed, 102 insertions, 0 deletions
diff --git a/spec/lib/gitlab/exclusive_lease_helpers/sleeping_lock_spec.rb b/spec/lib/gitlab/exclusive_lease_helpers/sleeping_lock_spec.rb
new file mode 100644
index 00000000000..8917eeec56f
--- /dev/null
+++ b/spec/lib/gitlab/exclusive_lease_helpers/sleeping_lock_spec.rb
@@ -0,0 +1,102 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::ExclusiveLeaseHelpers::SleepingLock, :clean_gitlab_redis_shared_state do
+  include ::ExclusiveLeaseHelpers
+
+  let(:timeout) { 1.second }
+  let(:delay) { 0.1.seconds }
+  let(:key) { SecureRandom.hex(10) }
+
+  subject { described_class.new(key, timeout: timeout, delay: delay) }
+
+  describe '#retried?' do
+    before do
+      stub_exclusive_lease(key, 'uuid')
+    end
+
+    context 'we have not made any attempts' do
+      it { is_expected.not_to be_retried }
+    end
+
+    context 'we just made a single (initial) attempt' do
+      it 'is not considered a retry' do
+        subject.send(:try_obtain)
+
+        is_expected.not_to be_retried
+      end
+    end
+
+    context 'made multiple attempts' do
+      it 'is considered a retry' do
+        2.times { subject.send(:try_obtain) }
+
+        is_expected.to be_retried
+      end
+    end
+  end
+
+  describe '#obtain' do
+    context 'when the lease is not held' do
+      before do
+        stub_exclusive_lease(key, 'uuid')
+      end
+
+      it 'obtains the lease on the first attempt, without sleeping' do
+        expect(subject).not_to receive(:sleep)
+
+        subject.obtain(10)
+
+        expect(subject).not_to be_retried
+      end
+    end
+
+    context 'when the lease is held elsewhere' do
+      let!(:lease) { stub_exclusive_lease_taken(key) }
+      let(:max_attempts) { 7 }
+
+      it 'retries to obtain a lease and raises an error' do
+        expect(subject).to receive(:sleep).with(delay).exactly(max_attempts - 1).times
+        expect(lease).to receive(:try_obtain).exactly(max_attempts).times
+
+        expect { subject.obtain(max_attempts) }.to raise_error('Failed to obtain a lock')
+      end
+
+      context 'when the delay is computed from the attempt number' do
+        let(:delay) { ->(n) { 3 * n } }
+
+        it 'uses the computation to determine the sleep length' do
+          expect(subject).to receive(:sleep).with(3).once
+          expect(subject).to receive(:sleep).with(6).once
+          expect(subject).to receive(:sleep).with(9).once
+          expect(lease).to receive(:try_obtain).exactly(4).times
+
+          expect { subject.obtain(4) }.to raise_error('Failed to obtain a lock')
+        end
+      end
+
+      context 'when lease is granted after retry' do
+        it 'knows that it retried' do
+          expect(subject).to receive(:sleep).with(delay).exactly(3).times
+          expect(lease).to receive(:try_obtain).exactly(3).times { nil }
+          expect(lease).to receive(:try_obtain).once { 'obtained' }
+
+          subject.obtain(max_attempts)
+
+          expect(subject).to be_retried
+        end
+      end
+    end
+
+    describe 'cancel' do
+      let!(:lease) { stub_exclusive_lease(key, 'uuid') }
+
+      it 'cancels the lease' do
+        expect(lease).to receive(:cancel)
+
+        subject.cancel
+      end
+    end
+  end
+end