assistant-storefront/spec/jobs/mutex_application_job_spec.rb

require 'rails_helper'

RSpec.describe MutexApplicationJob do
  let(:lock_manager) { instance_double(Redis::LockManager) }
  let(:lock_key) { 'test_key' }

  before do
    allow(Redis::LockManager).to receive(:new).and_return(lock_manager)
    allow(lock_manager).to receive(:lock).and_return(true)
    allow(lock_manager).to receive(:unlock).and_return(true)
  end

  describe '#with_lock' do
    it 'acquires the lock and yields the block if lock is not acquired' do
      expect(lock_manager).to receive(:lock).with(lock_key, Redis::LockManager::LOCK_TIMEOUT).and_return(true)
      expect(lock_manager).to receive(:unlock).with(lock_key).and_return(true)

      expect { |b| described_class.new.send(:with_lock, lock_key, &b) }.to yield_control
    end

    it 'acquires the lock with custom timeout' do
      expect(lock_manager).to receive(:lock).with(lock_key, 5.seconds).and_return(true)
      expect(lock_manager).to receive(:unlock).with(lock_key).and_return(true)

      expect { |b| described_class.new.send(:with_lock, lock_key, 5.seconds, &b) }.to yield_control
    end

    it 'raises LockAcquisitionError if it cannot acquire the lock' do
      allow(lock_manager).to receive(:lock).with(lock_key, Redis::LockManager::LOCK_TIMEOUT).and_return(false)

      expect do
        described_class.new.send(:with_lock, lock_key) do
          # Do nothing
        end
      end.to raise_error(StandardError) { |error| expect(error.class.name).to eq('MutexApplicationJob::LockAcquisitionError') }
    end

    it 'raises StandardError if it execution raises it' do
      allow(lock_manager).to receive(:lock).with(lock_key, Redis::LockManager::LOCK_TIMEOUT).and_return(false)
      allow(lock_manager).to receive(:unlock).with(lock_key).and_return(true)

      expect do
        described_class.new.send(:with_lock, lock_key) do
          raise StandardError
        end
      end.to raise_error(StandardError)
    end

    it 'ensures that the lock is released even if there is an error during block execution' do
      expect(lock_manager).to receive(:lock).with(lock_key, Redis::LockManager::LOCK_TIMEOUT).and_return(true)
      expect(lock_manager).to receive(:unlock).with(lock_key).and_return(true)

      expect do
        described_class.new.send(:with_lock, lock_key) { raise StandardError }
      end.to raise_error(StandardError)
    end
  end
end