feat: add lock heartbeat to prevent mid-execution expiry (#64)

tests/test_integration.py

@@ -7,7 +7,7 @@ In CI a Redis service is started before the test step.
 import pytest
 
 from taskiq_deduplication import DuplicateTaskError, RedisDeduplicationMiddleware
-from taskiq_deduplication.utils import RELEASE_LUA_SCRIPT
+from taskiq_deduplication.utils import REFRESH_LUA_SCRIPT, RELEASE_LUA_SCRIPT
 
 
 @pytest.fixture
@@ -15,6 +15,7 @@ def mw(real_redis):
     middleware = RedisDeduplicationMiddleware(redis_url="redis://localhost:6379/15")
     middleware._redis = real_redis
     middleware._release_script = real_redis.register_script(RELEASE_LUA_SCRIPT)
+    middleware._refresh_script = real_redis.register_script(REFRESH_LUA_SCRIPT)
     return middleware
 
 
@@ -68,6 +69,31 @@ async def test_ttl_is_applied(mw, real_redis, make_message):
     assert 0 < ttl <= mw.default_ttl
 
 
+@pytest.mark.integration
+async def test_heartbeat_keeps_long_running_lock_alive(
+    mw, real_redis, make_message, make_result
+):
+    import asyncio
+
+    from taskiq_deduplication.middleware import DEDUP_TTL_LABEL
+
+    # 1s TTL with a sub-second heartbeat: without refresh the lock would expire.
+    mw.heartbeat_interval = 0.2
+    msg = make_message(labels={DEDUP_TTL_LABEL: 1})
+    await mw.pre_send(msg)
+    key = mw._build_deduplication_key(msg)
+    await mw.pre_execute(msg)
+    try:
+        # outlive the original TTL; the heartbeat should keep the lock present
+        await asyncio.sleep(1.5)
+        assert await real_redis.exists(key)
+        with pytest.raises(DuplicateTaskError):
+            await mw.pre_send(make_message(labels={DEDUP_TTL_LABEL: 1}))
+    finally:
+        await mw.post_execute(msg, make_result())
+    assert not await real_redis.exists(key)
+
+
 @pytest.mark.integration
 async def test_explicit_key_end_to_end(mw, real_redis, make_message, make_result):
     from taskiq_deduplication.middleware import DEDUP_EXPLICIT_KEY_LABEL