feat: switch to requests-cache for style caching (andreoliwa#467)

Use `requests_cache.CachedSession()` for URL fetching and caching. file and
pypackage styles are no longer cached but reuse the original file each time.

This resolves issues with concurrent access to the cache, as it is now a sqlite
database file.

pyproject.toml

@@ -76,7 +76,6 @@ pluggy = "*"
 autorepr = "*"
 loguru = "*"
 ConfigUpdater = "*"
-cachy = "*"
 importlib-resources = { version = "*", python = ">=3.7, <3.9" }
 flatten-dict = "*"
 dpath = "*"
@@ -103,6 +102,7 @@ pytest-datadir = { version = "*", optional = true }
 sphinx = { version = "*", optional = true }
 sphinx_rtd_theme = { version = "*", optional = true }
 sphobjinv = { version = "*", optional = true }
+requests-cache = "*"
 
 [tool.poetry.extras]
 lint = ["pylint"]

src/nitpick/style/cache.py

@@ -1,36 +1,44 @@
 """Cache functions and configuration for styles."""
+from __future__ import annotations
+
 import re
 from datetime import timedelta
-from typing import Tuple
 
 from loguru import logger
+from requests_cache.cache_control import DO_NOT_CACHE, NEVER_EXPIRE
 
 from nitpick.enums import CachingEnum
 
 REGEX_CACHE_UNIT = re.compile(r"(?P<number>\d+)\s+(?P<unit>(minute|hour|day|week))", re.IGNORECASE)
+EXPIRES_DEFAULTS = {
+    CachingEnum.NEVER: DO_NOT_CACHE,
+    CachingEnum.FOREVER: NEVER_EXPIRE,
+    CachingEnum.EXPIRES: timedelta(hours=1),
+}
 
 
-def parse_cache_option(cache_option: str) -> Tuple[CachingEnum, timedelta]:
+def parse_cache_option(cache_option: str) -> tuple[CachingEnum, timedelta | int]:
     """Parse the cache option provided on pyproject.toml.
 
     If no cache if provided or is invalid, the default is *one hour*.
+
     """
-    clean_cache_option = cache_option.strip().lower() if cache_option else ""
-    mapping = {CachingEnum.NEVER.name.lower(): CachingEnum.NEVER, CachingEnum.FOREVER.name.lower(): CachingEnum.FOREVER}
-    simple_cache = mapping.get(clean_cache_option)
-    if simple_cache:
-        logger.info(f"Simple cache option: {simple_cache.name}")
-        return simple_cache, timedelta()
-
-    default = CachingEnum.EXPIRES, timedelta(hours=1)
-    if not clean_cache_option:
-        return default
-
-    for match in REGEX_CACHE_UNIT.finditer(clean_cache_option):
-        plural_unit = match.group("unit") + "s"
-        number = int(match.group("number"))
-        logger.info(f"Cache option with unit: {number} {plural_unit}")
-        return CachingEnum.EXPIRES, timedelta(**{plural_unit: number})
-
-    logger.warning(f"Invalid cache option: {clean_cache_option}. Defaulting to 1 hour")
-    return default
+    clean_cache_option = cache_option.strip().upper() if cache_option else ""
+    try:
+        caching = CachingEnum[clean_cache_option]
+        logger.info(f"Simple cache option: {caching.name}")
+    except KeyError:
+        caching = CachingEnum.EXPIRES
+
+    expires_after = EXPIRES_DEFAULTS[caching]
+    if caching is CachingEnum.EXPIRES and clean_cache_option:
+        for match in REGEX_CACHE_UNIT.finditer(clean_cache_option):
+            plural_unit = match.group("unit").lower() + "s"
+            number = int(match.group("number"))
+            logger.info(f"Cache option with unit: {number} {plural_unit}")
+            expires_after = timedelta(**{plural_unit: number})
+            break
+        else:
+            logger.warning(f"Invalid cache option: {clean_cache_option}. Defaulting to 1 hour")
+
+    return caching, expires_after