[CHORE] cleanup cache and exception on make test (#1899)

* [CHORE] cleanup cache and exception on `make test`

moved the invalidate_forever task to proper location and use `create_permanent_task`.
and there was a Task never awaited Exception when running tests

* imrpove expiration test

* move cache into utils

* fix issue with pytest_asyncio

s

---------

Co-authored-by: jacksn <jkranawetter05@gmail.com>

lnbits/app.py

@@ -20,7 +20,6 @@ from slowapi import Limiter
 from slowapi.util import get_remote_address
 from starlette.responses import JSONResponse
 
-from lnbits.cache import cache
 from lnbits.core.crud import get_installed_extensions
 from lnbits.core.helpers import migrate_extension_database
 from lnbits.core.services import websocketUpdater
@@ -30,6 +29,7 @@ from lnbits.core.tasks import (  # register_watchdog,; unregister_watchdog,
 )
 from lnbits.settings import settings
 from lnbits.tasks import cancel_all_tasks, create_permanent_task
+from lnbits.utils.cache import cache
 from lnbits.wallets import get_wallet_class, set_wallet_class
 
 from .commands import db_versions, load_disabled_extension_list, migrate_databases
@@ -358,8 +358,6 @@ def register_startup(app: FastAPI):
             if settings.lnbits_admin_ui:
                 initialize_server_logger()
 
-            asyncio.create_task(cache.invalidate_forever())
-
         except Exception as e:
             logger.error(str(e))
             raise ImportError("Failed to run 'startup' event.")
@@ -431,6 +429,7 @@ def register_async_tasks(app):
         create_permanent_task(check_pending_payments)
         create_permanent_task(invoice_listener)
         create_permanent_task(internal_invoice_listener)
+        create_permanent_task(cache.invalidate_forever)
         register_task_listeners()
         register_killswitch()
         # await run_deferred_async() # calle: doesn't do anyting?

lnbits/utils/cache.py

@@ -17,7 +17,8 @@ class Cache:
     Small caching utility providing simple get/set interface (very much like redis)
     """
 
-    def __init__(self) -> None:
+    def __init__(self, interval: float = 10) -> None:
+        self.interval = interval
         self._values: dict[Any, Cached] = {}
 
     def get(self, key: str, default=None) -> Optional[Any]:
@@ -50,10 +51,10 @@ class Cache:
             self.set(key, value, expiry=expiry)
             return value
 
-    async def invalidate_forever(self, interval: float = 10):
+    async def invalidate_forever(self):
         while True:
             try:
-                await asyncio.sleep(interval)
+                await asyncio.sleep(self.interval)
                 ts = time()
                 expired = [k for k, v in self._values.items() if v.expiry < ts]
                 for k in expired:

lnbits/utils/exchange_rates.py

@@ -4,7 +4,7 @@ from typing import Callable, NamedTuple
 import httpx
 from loguru import logger
 
-from lnbits.cache import cache
+from lnbits.utils.cache import cache
 
 currencies = {
     "AED": "United Arab Emirates Dirham",

tests/core/test_cache.py

@@ -2,23 +2,22 @@ import asyncio
 
 import pytest
 
-from lnbits.cache import Cache
+from lnbits.utils.cache import Cache
 from tests.conftest import pytest_asyncio
 
-
-@pytest_asyncio.fixture(scope="session")
-async def cache():
-    cache = Cache()
-
-    task = asyncio.create_task(cache.invalidate_forever(interval=0.1))
-    yield cache
-    task.cancel()
-
-
 key = "foo"
 value = "bar"
 
 
+@pytest_asyncio.fixture
+async def cache():
+    cache = Cache(interval=0.1)
+
+    task = asyncio.create_task(cache.invalidate_forever())
+    yield cache
+    task.cancel()
+
+
 @pytest.mark.asyncio
 async def test_cache_get_set(cache):
     cache.set(key, value)
@@ -29,8 +28,15 @@ async def test_cache_get_set(cache):
 
 @pytest.mark.asyncio
 async def test_cache_expiry(cache):
+    # gets expired by `get` call
+    cache.set(key, value, expiry=0.01)
+    await asyncio.sleep(0.02)
+    assert not cache.get(key)
+
+    # gets expired by invalidation task
     cache.set(key, value, expiry=0.1)
     await asyncio.sleep(0.2)
+    assert key not in cache._values
     assert not cache.get(key)