Files
simply_based/spec/redis_replacements_spec.rb
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bterkuileandClaude Sonnet 5 bde6df57f4 Counter/Lock: Redis INCR parity and safe lock release
- Counter#increment now seeds a missing key at the delta (Redis INCR/INCRBY
  semantics). Couchbase's native increment seeds at 'initial' and ignores the
  delta on creation, so the first INCR returned 0 — a drop-in replacement that
  silently undercounts by one is exactly the kind of bug nobody ever finds.
  Explicit initial: still overrides. Decrement keeps initial: 0 and its
  unsigned clamp-at-zero divergence from Redis is now documented and tested.
- Lock#release requires the CAS handle: passing nil used to delete the lock
  document unconditionally, so any caller could unlock a lock it never held.
  force_release! is the explicit administrative override.
- Lock#acquire validates a positive ttl — a nil/zero ttl would create a lock
  that survives its holder's crash forever.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-07-06 18:42:17 -05:00

80 lines
2.9 KiB
Ruby

require 'spec_helper'
# Couchbase-backed replacements for common Redis uses: atomic counters, a Rails
# cache store, and a distributed lock — all on the same cluster as the models.
RSpec.describe 'Redis replacements' do
describe SimplyBased::Counter do
subject(:counter) { described_class.new }
it 'atomically increments with Redis INCR semantics (first INCR of a missing key returns the delta)' do
expect(counter.increment('c:hits')).to eq(1)
expect(counter.increment('c:hits')).to eq(2)
expect(counter.increment('c:hits', 5)).to eq(7)
expect(counter.get('c:hits')).to eq(7)
end
it 'seeds at an explicit initial value when given' do
expect(counter.increment('c:seeded', 1, initial: 100)).to eq(100)
expect(counter.increment('c:seeded')).to eq(101)
end
it 'decrements and resets' do
counter.increment('c:n', 0, initial: 10)
expect(counter.decrement('c:n', 3)).to eq(7)
expect(counter.reset('c:n', 0)).to eq(0)
expect(counter.get('c:n')).to eq(0)
end
it 'clamps decrement at zero (unsigned Couchbase counters; Redis would go negative)' do
counter.reset('c:clamp', 1)
expect(counter.decrement('c:clamp', 5)).to eq(0)
end
end
describe SimplyBased::Cache do
subject(:cache) { described_class.new(namespace: 'test') }
it 'works as an ActiveSupport::Cache::Store (read/write/fetch/delete)' do
cache.write('k', { 'a' => 1 })
expect(cache.read('k')).to eq({ 'a' => 1 })
expect(cache.fetch('k2') { [1, 2, 3] }).to eq([1, 2, 3])
expect(cache.read('k2')).to eq([1, 2, 3])
cache.delete('k')
expect(cache.read('k')).to be_nil
end
end
describe SimplyBased::Lock do
subject(:lock) { described_class.new }
it 'grants the lock to one holder and blocks a second acquire' do
handle = lock.acquire('job:1', ttl: 30)
expect(handle).not_to be_nil
expect(lock.acquire('job:1', ttl: 30)).to be_nil # already held
lock.release('job:1', handle)
expect(lock.acquire('job:1', ttl: 30)).not_to be_nil # released → free
end
it 'refuses to release without the CAS handle' do
lock.acquire('job:guard', ttl: 30)
expect { lock.release('job:guard', nil) }.to raise_error(ArgumentError)
expect(lock.acquire('job:guard', ttl: 30)).to be_nil # still held
lock.force_release!('job:guard')
expect(lock.acquire('job:guard', ttl: 30)).not_to be_nil
end
it 'rejects a missing/zero ttl (a crashed holder must never leave an immortal lock)' do
expect { lock.acquire('job:immortal', ttl: nil) }.to raise_error(ArgumentError)
expect { lock.acquire('job:immortal', ttl: 0) }.to raise_error(ArgumentError)
end
it 'runs a critical section with with_lock' do
ran = false
lock.with_lock('job:2') { ran = true }
expect(ran).to be(true)
# lock auto-released after the block → re-acquirable
expect(lock.acquire('job:2')).not_to be_nil
end
end
end