Add return value for MySQLCache.touch() (#938)

Author: adamchainz

HISTORY.rst

@@ -2,6 +2,9 @@
 History
 =======
 
+* Make ``MySQLCache.touch()`` return ``True`` if the key was touched, ``False`` otherwise.
+  This return value was missing since the method was added for Django 2.1.
+
 4.7.1 (2022-08-11)
 ------------------
 

src/django_mysql/cache.py

@@ -442,16 +442,17 @@ def clear(self) -> None:
 
     def touch(
         self, key: str, timeout: Any = DEFAULT_TIMEOUT, version: int | None = None
-    ) -> None:
+    ) -> bool:
         key = self.make_key(key, version=version)
         self.validate_key(key)
         exp = self.get_backend_timeout(timeout)
         db = router.db_for_write(self.cache_model_class)
         table = connections[db].ops.quote_name(self._table)
         with connections[db].cursor() as cursor:
-            cursor.execute(
+            affected_rows = cursor.execute(
                 self._touch_query.format(table=table), [exp, key, self._now()]
             )
+        return affected_rows > 0
 
     _touch_query = collapse_spaces(
         """

tests/testapp/test_cache.py

@@ -349,20 +349,23 @@ def test_clear(self):
 
     def test_touch_without_timeout(self):
         cache.set("key1", "spam", timeout=0.1)
-        cache.touch("key1", timeout=0.4)
+        result = cache.touch("key1", timeout=0.4)
+        assert result is True
         time.sleep(0.2)
         assert "key1" in cache
 
     def test_touch_with_timeout(self):
         cache.set("key1", "spam", timeout=0.1)
-        cache.touch("key1")
+        result = cache.touch("key1")
+        assert result is True
         time.sleep(0.2)
         assert "key1" in cache
 
     def test_touch_already_expired(self):
         cache.set("key1", "spam", timeout=0.1)
         time.sleep(0.2)
-        cache.touch("key1", timeout=0.4)
+        result = cache.touch("key1", timeout=0.4)
+        assert result is False
         assert "key1" not in cache
 
     def test_long_timeout(self):