Merge pull request #527 from JWCook/fix-expire-override

Fix disabling expiration for a single request

.all-contributorsrc

@@ -744,6 +744,15 @@
       "contributions": [
         "bug"
       ]
+    },
+    {
+      "login": "johnraz",
+      "name": "Jonathan Liuti",
+      "avatar_url": "https://avatars.githubusercontent.com/u/304164?v=4",
+      "profile": "https://github.com/johnraz",
+      "contributions": [
+        "bug"
+      ]
     }
   ],
   "contributorsPerLine": 7,

HISTORY.md

@@ -1,8 +1,9 @@
 # History
 
-## 0.9.2 (Unreleased)
-* Support `params`, `data`, and `json` as positional arguments to `CachedSession.request()` (fixes
-  regression in `0.9.0`)
+## 0.9.2 (2022-02-15)
+Fix some regression bugs introduced in 0.9.0:
+* Add support `params` as a positional argument to `CachedSession.request()`
+* Add support for disabling expiration for a single request with `CachedSession.request(..., expire_after=-1)`
 
 ## 0.9.1 (2022-01-15)
 * Add support for python 3.10.2 and 3.9.10 (regarding resolving `ForwardRef` types during deserialization)

docs/user_guide/expiration.md

@@ -75,10 +75,10 @@ retrieving a new response. If you would like to use expired response data in the
 
 For example:
 ```python
->>> # Cache a test response that will expire immediately
+>>> # Cache a test response and wait until it's expired
 >>> session = CachedSession(stale_if_error=True)
->>> session.get('https://httpbin.org/get', expire_after=0.0001)
->>> time.sleep(0.0001)
+>>> session.get('https://httpbin.org/get', expire_after=1)
+>>> time.sleep(1)
 ```
 
 Afterward, let's say the page has moved and you get a 404, or the site is experiencing downtime and

requests_cache/cache_control.py

@@ -27,8 +27,9 @@
 
 __all__ = ['DO_NOT_CACHE', 'CacheActions']
 
-# May be set by either headers or expire_after param to disable caching
+# May be set by either headers or expire_after param to disable caching or disable expiration
 DO_NOT_CACHE = 0
+NEVER_EXPIRE = -1
 # Supported Cache-Control directives
 CACHE_DIRECTIVES = ['immutable', 'max-age', 'no-cache', 'no-store']
 
@@ -139,7 +140,7 @@ def update_from_response(self, response: Response):
 
         # Check headers for expiration, validators, and other cache directives
         if directives.get('immutable'):
-            self.expire_after = -1
+            self.expire_after = NEVER_EXPIRE
         else:
             self.expire_after = coalesce(
                 directives.get('max-age'), directives.get('expires'), self.expire_after
@@ -156,7 +157,7 @@ def update_from_response(self, response: Response):
 def get_expiration_datetime(expire_after: ExpirationTime) -> Optional[datetime]:
     """Convert an expiration value in any supported format to an absolute datetime"""
     # Never expire
-    if expire_after is None or expire_after == -1:
+    if expire_after is None or expire_after == NEVER_EXPIRE:
         return None
     # Expire immediately
     elif try_int(expire_after) == DO_NOT_CACHE:
@@ -173,10 +174,10 @@ def get_expiration_datetime(expire_after: ExpirationTime) -> Optional[datetime]:
     return datetime.utcnow() + expire_after
 
 
-def get_expiration_seconds(expire_after: ExpirationTime) -> Optional[int]:
+def get_expiration_seconds(expire_after: ExpirationTime) -> int:
     """Convert an expiration value in any supported format to an expiration time in seconds"""
     expires = get_expiration_datetime(expire_after)
-    return ceil((expires - datetime.utcnow()).total_seconds()) if expires else None
+    return ceil((expires - datetime.utcnow()).total_seconds()) if expires else NEVER_EXPIRE
 
 
 def get_cache_directives(headers: Mapping) -> Dict:
@@ -242,7 +243,10 @@ def to_utc(dt: datetime):
 
 def try_int(value: Any) -> Optional[int]:
     """Convert a value to an int, if possible, otherwise ``None``"""
-    return int(str(value)) if str(value).isnumeric() else None
+    try:
+        return int(value)
+    except (TypeError, ValueError):
+        return None
 
 
 def url_match(url: str, pattern: str) -> bool:

tests/unit/test_session.py

@@ -10,7 +10,7 @@
 
 import pytest
 import requests
-from requests import Request
+from requests import Request, RequestException
 from requests.structures import CaseInsensitiveDict
 
 from requests_cache import ALL_METHODS, CachedResponse, CachedSession
@@ -154,12 +154,12 @@ def test_response_history(mock_session):
 
 def test_repr(mock_session):
     """Test session and cache string representations"""
-    mock_session.expire_after = 10.5
+    mock_session.expire_after = 11
     mock_session.cache.responses['key'] = 'value'
     mock_session.cache.redirects['key'] = 'value'
     mock_session.cache.redirects['key_2'] = 'value'
 
-    assert mock_session.cache.cache_name in repr(mock_session) and '10.5' in repr(mock_session)
+    assert mock_session.cache.cache_name in repr(mock_session) and '11' in repr(mock_session)
     assert '2 redirects' in str(mock_session.cache) and '1 responses' in str(mock_session.cache)
 
 
@@ -515,9 +515,9 @@ def test_expired_request_error(mock_session):
     """Without stale_if_error (default), if there is an error while re-fetching an expired
     response, the request should be re-raised and the expired item deleted"""
     mock_session.stale_if_error = False
-    mock_session.expire_after = 0.01
+    mock_session.expire_after = 1
     mock_session.get(MOCKED_URL)
-    time.sleep(0.01)
+    time.sleep(1)
 
     with patch.object(mock_session.cache, 'save_response', side_effect=ValueError):
         with pytest.raises(ValueError):
@@ -528,25 +528,25 @@ def test_expired_request_error(mock_session):
 def test_stale_if_error__exception(mock_session):
     """With stale_if_error, expect to get old cache data if there is an exception during a request"""
     mock_session.stale_if_error = True
-    mock_session.expire_after = 0.2
+    mock_session.expire_after = 1
 
     assert mock_session.get(MOCKED_URL).from_cache is False
     assert mock_session.get(MOCKED_URL).from_cache is True
-    time.sleep(0.2)
-    with patch.object(mock_session.cache, 'save_response', side_effect=ValueError):
+    time.sleep(1)
+    with patch.object(mock_session.cache, 'save_response', side_effect=RequestException):
         response = mock_session.get(MOCKED_URL)
         assert response.from_cache is True and response.is_expired is True
 
 
 def test_stale_if_error__error_code(mock_session):
     """With stale_if_error, expect to get old cache data if a response has an error status code"""
     mock_session.stale_if_error = True
-    mock_session.expire_after = 0.2
+    mock_session.expire_after = 1
     mock_session.allowable_codes = (200, 404)
 
     assert mock_session.get(MOCKED_URL_404).from_cache is False
 
-    time.sleep(0.2)
+    time.sleep(1)
     response = mock_session.get(MOCKED_URL_404)
     assert response.from_cache is True and response.is_expired is True
 
@@ -718,8 +718,8 @@ def test_remove_expired_responses__per_request(mock_session):
     assert len(mock_session.cache.responses) == 1
 
 
-def test_per_request__expiration(mock_session):
-    """No per-session expiration is set, but then overridden with per-request expiration"""
+def test_per_request__enable_expiration(mock_session):
+    """No per-session expiration is set, but then overridden for a single request"""
     mock_session.expire_after = None
     response = mock_session.get(MOCKED_URL, expire_after=1)
     assert response.from_cache is False
@@ -730,6 +730,15 @@ def test_per_request__expiration(mock_session):
     assert response.from_cache is False
 
 
+def test_per_request__disable_expiration(mock_session):
+    """A per-session expiration is set, but then disabled for a single request"""
+    mock_session.expire_after = 60
+    response = mock_session.get(MOCKED_URL, expire_after=-1)
+    response = mock_session.get(MOCKED_URL, expire_after=-1)
+    assert response.from_cache is True
+    assert response.expires is None
+
+
 def test_per_request__prepared_request(mock_session):
     """The same should work for PreparedRequests with CachedSession.send()"""
     mock_session.expire_after = None