decorators.cache: use Generic type. drop py38

Author: cybergrind

fan_tools/__init__.py

@@ -1 +1 @@
-__version__ = '3.13.0'
+__version__ = '4.0.0'

fan_tools/python/decorators.py

@@ -3,7 +3,7 @@
 import functools
 import logging
 from pathlib import Path
-from typing import Awaitable, Callable, Protocol, Type, TypeVar, Union
+from typing import Awaitable, Callable, Generic, Protocol, Type, TypeVar, Union
 
 
 try:
@@ -77,34 +77,34 @@ def json(self) -> str:
         ...
 
 
-FuncType = Callable[P, Awaitable[PydanticBaseModel]]
+ModelType = TypeVar('ModelType', bound=PydanticBaseModel)
 
 
-class cache_async:
+class cache_async(Generic[ModelType]):
     """
     file cache for async functions that returns pydantic models
     NB: it doesn't use parameters to generate the cache file name
     """
 
-    def __init__(self, fname: Path, model: PydanticBaseModel, default: PydanticBaseModel):
+    def __init__(self, fname: Path, model: ModelType, default: ModelType):
         self.fname = fname
         self._default = default
         self.cache = default
         # load from file
         if self.fname.exists():
             self.cache = model.parse_file(self.fname)
 
-    def __call__(self, func: FuncType[P]) -> FuncType[P]:
+    def __call__(self, func: Callable[P, Awaitable[ModelType]]):
         @functools.wraps(func)
-        async def wrapper(*args: P.args, **kwargs: P.kwargs) -> PydanticBaseModel:
+        async def wrapper(*args: P.args, **kwargs: P.kwargs) -> ModelType:
             if self.cache:
                 return self.cache
             value = await func(*args, **kwargs)
             self.cache = value
             self.fname.write_text(self.cache.json())
             return value
 
-        wrapper.reset_cache = self.reset_cache
+        wrapper.reset_cache = self.reset_cache  # type: ignore
 
         return wrapper
 

pyproject.toml

@@ -21,8 +21,9 @@ classifiers = [
   'Operating System :: POSIX :: Linux',
   'Operating System :: Unix',
   'Programming Language :: Python',
-  'Programming Language :: Python :: 3.8',
   'Programming Language :: Python :: 3.9',
+  'Programming Language :: Python :: 3.10',
+  'Programming Language :: Python :: 3.11',
   'Programming Language :: Python :: Implementation',
   'Programming Language :: Python :: Implementation :: CPython',
   'Topic :: Software Development',

tests/test_decorators.py

@@ -10,7 +10,7 @@ async def test_01_simplest(self, tmp_path):
 
         model.json.return_value = '{"a": "b"}'
 
-        @cache_async(fname, model, {})
+        @cache_async[type(dict)](fname, model, {})
         async def func():
             return model
 

tox.ini

@@ -1,7 +1,7 @@
 [tox]
 min_version = 4.3
 isolated_build = True
-envlist = py{38,39,310}-django{32,40} #,mypy
+envlist = py{39,310,311}-django{32,40} #,mypy
 
 [testenv]
 extras =