Fix serialization in filesystem backend with binary content that is also valid UTF-8

9 files changed, 55 insertions, 41 deletions

diff --git a/.all-contributorsrc b/.all-contributorsrc
index d883382..cab0a59 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -753,6 +753,15 @@
       "contributions": [
         "bug"
       ]
+    },
+    {
+      "login": "rasmuse",
+      "name": "Rasmus Einarsson",
+      "avatar_url": "https://avatars.githubusercontent.com/u/1210973?v=4",
+      "profile": "https://rasmuse.github.io/",
+      "contributions": [
+        "bug"
+      ]
     }
   ],
   "contributorsPerLine": 7,
diff --git a/CONTRIBUTORS.md b/CONTRIBUTORS.md
index a53abae..749c0eb 100644
--- a/CONTRIBUTORS.md
+++ b/CONTRIBUTORS.md
@@ -74,31 +74,32 @@ contributions that have helped to improve requests-cache:
   <tr>
     <td align="center"><a href="https://github.com/parkerhancock"><img src="https://avatars.githubusercontent.com/u/633163?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Parker Hancock</b></sub></a><br /><a href="https://github.com/reclosedev/requests-cache/commits?author=parkerhancock" title="Code">💻</a> <a href="#feature-parkerhancock" title="New features">✨</a> <a href="https://github.com/reclosedev/requests-cache/issues?q=author%3Aparkerhancock" title="Bug reports">🐛</a> <a href="https://github.com/reclosedev/requests-cache/commits?author=parkerhancock" title="Tests">⚠️</a> <a href="https://github.com/reclosedev/requests-cache/commits?author=parkerhancock" title="Documentation">📖</a> <a href="#security-parkerhancock" title="Security">🛡️</a> <a href="#ideas-parkerhancock" title="Ideas, Planning, & Feedback">🤔</a></td>
     <td align="center"><a href="https://phil.red/"><img src="https://avatars.githubusercontent.com/u/291575?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Philipp A.</b></sub></a><br /><a href="https://github.com/reclosedev/requests-cache/issues?q=author%3Aflying-sheep" title="Bug reports">🐛</a></td>
+    <td align="center"><a href="https://rasmuse.github.io/"><img src="https://avatars.githubusercontent.com/u/1210973?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Rasmus Einarsson</b></sub></a><br /><a href="https://github.com/reclosedev/requests-cache/issues?q=author%3Arasmuse" title="Bug reports">🐛</a></td>
     <td align="center"><a href="https://roderic.ca/"><img src="https://avatars.githubusercontent.com/u/6867226?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Roderic Day</b></sub></a><br /><a href="https://github.com/reclosedev/requests-cache/issues?q=author%3ARodericDay" title="Bug reports">🐛</a></td>
     <td align="center"><a href="https://github.com/reclosedev"><img src="https://avatars.githubusercontent.com/u/660112?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Roman Haritonov</b></sub></a><br /><a href="https://github.com/reclosedev/requests-cache/commits?author=reclosedev" title="Code">💻</a> <a href="#maintenance-reclosedev" title="Maintenance">🚧</a> <a href="#feature-reclosedev" title="New features">✨</a> <a href="https://github.com/reclosedev/requests-cache/issues?q=author%3Areclosedev" title="Bug reports">🐛</a> <a href="https://github.com/reclosedev/requests-cache/commits?author=reclosedev" title="Tests">⚠️</a> <a href="https://github.com/reclosedev/requests-cache/commits?author=reclosedev" title="Documentation">📖</a> <a href="#infra-reclosedev" title="Infrastructure (Hosting, Build-Tools, etc)">🚇</a></td>
     <td align="center"><a href="https://www.facebook.com/avasamdev"><img src="https://avatars.githubusercontent.com/u/1350584?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Samuel T.</b></sub></a><br /><a href="https://github.com/reclosedev/requests-cache/issues?q=author%3AAvasam" title="Bug reports">🐛</a> <a href="#ideas-Avasam" title="Ideas, Planning, & Feedback">🤔</a></td>
     <td align="center"><a href="https://sebastian-hoeffner.de/"><img src="https://avatars.githubusercontent.com/u/1836815?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Sebastian Höffner</b></sub></a><br /><a href="https://github.com/reclosedev/requests-cache/commits?author=shoeffner" title="Code">💻</a> <a href="#feature-shoeffner" title="New features">✨</a> <a href="https://github.com/reclosedev/requests-cache/commits?author=shoeffner" title="Tests">⚠️</a> <a href="#ideas-shoeffner" title="Ideas, Planning, & Feedback">🤔</a></td>
-    <td align="center"><a href="https://github.com/grubberr"><img src="https://avatars.githubusercontent.com/u/195743?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Serhii Chvaliuk</b></sub></a><br /><a href="https://github.com/reclosedev/requests-cache/issues?q=author%3Agrubberr" title="Bug reports">🐛</a> <a href="https://github.com/reclosedev/requests-cache/commits?author=grubberr" title="Code">💻</a></td>
   </tr>
   <tr>
+    <td align="center"><a href="https://github.com/grubberr"><img src="https://avatars.githubusercontent.com/u/195743?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Serhii Chvaliuk</b></sub></a><br /><a href="https://github.com/reclosedev/requests-cache/issues?q=author%3Agrubberr" title="Bug reports">🐛</a> <a href="https://github.com/reclosedev/requests-cache/commits?author=grubberr" title="Code">💻</a></td>
     <td align="center"><a href="https://sbiewald.de/"><img src="https://avatars.githubusercontent.com/u/5983372?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Simon Biewald</b></sub></a><br /><a href="#security-Varbin" title="Security">🛡️</a> <a href="#ideas-Varbin" title="Ideas, Planning, & Feedback">🤔</a></td>
     <td align="center"><a href="https://github.com/jseabold"><img src="https://avatars.githubusercontent.com/u/296164?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Skipper Seabold</b></sub></a><br /><a href="https://github.com/reclosedev/requests-cache/issues?q=author%3Ajseabold" title="Bug reports">🐛</a></td>
     <td align="center"><a href="http://pathmind.com/"><img src="https://avatars.githubusercontent.com/u/1197406?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Slin Lee</b></sub></a><br /><a href="https://github.com/reclosedev/requests-cache/commits?author=slinlee" title="Documentation">📖</a></td>
     <td align="center"><a href="https://www.stavros.io/"><img src="https://avatars.githubusercontent.com/u/23648?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Stavros Korokithakis</b></sub></a><br /><a href="#infra-skorokithakis" title="Infrastructure (Hosting, Build-Tools, etc)">🚇</a> <a href="#tool-skorokithakis" title="Tools">🔧</a> <a href="https://github.com/reclosedev/requests-cache/commits?author=skorokithakis" title="Documentation">📖</a></td>
     <td align="center"><a href="https://cheginit.github.io/"><img src="https://avatars.githubusercontent.com/u/13016644?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Taher Chegini</b></sub></a><br /><a href="https://github.com/reclosedev/requests-cache/issues?q=author%3Acheginit" title="Bug reports">🐛</a></td>
     <td align="center"><a href="https://vladimir.panteleev.md/"><img src="https://avatars.githubusercontent.com/u/160894?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Vladimir Panteleev</b></sub></a><br /><a href="#ideas-CyberShadow" title="Ideas, Planning, & Feedback">🤔</a></td>
-    <td align="center"><a href="https://sansec.io/"><img src="https://avatars.githubusercontent.com/u/1145479?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Willem de Groot</b></sub></a><br /><a href="https://github.com/reclosedev/requests-cache/commits?author=gwillem" title="Code">💻</a> <a href="https://github.com/reclosedev/requests-cache/issues?q=author%3Agwillem" title="Bug reports">🐛</a></td>
   </tr>
   <tr>
+    <td align="center"><a href="https://sansec.io/"><img src="https://avatars.githubusercontent.com/u/1145479?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Willem de Groot</b></sub></a><br /><a href="https://github.com/reclosedev/requests-cache/commits?author=gwillem" title="Code">💻</a> <a href="https://github.com/reclosedev/requests-cache/issues?q=author%3Agwillem" title="Bug reports">🐛</a></td>
     <td align="center"><a href="https://github.com/WouterVH"><img src="https://avatars.githubusercontent.com/u/469509?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Wouter Vanden Hove</b></sub></a><br /><a href="https://github.com/reclosedev/requests-cache/issues?q=author%3AWouterVH" title="Bug reports">🐛</a></td>
     <td align="center"><a href="https://github.com/YetAnotherNerd"><img src="https://avatars.githubusercontent.com/u/320738?v=4?s=100" width="100px;" alt=""/><br /><sub><b>YetAnotherNerd</b></sub></a><br /><a href="https://github.com/reclosedev/requests-cache/commits?author=YetAnotherNerd" title="Code">💻</a> <a href="#feature-YetAnotherNerd" title="New features">✨</a> <a href="https://github.com/reclosedev/requests-cache/issues?q=author%3AYetAnotherNerd" title="Bug reports">🐛</a></td>
     <td align="center"><a href="https://github.com/aaron-mf1"><img src="https://avatars.githubusercontent.com/u/65560918?v=4?s=100" width="100px;" alt=""/><br /><sub><b>aaron-mf1</b></sub></a><br /><a href="#ideas-aaron-mf1" title="Ideas, Planning, & Feedback">🤔</a></td>
     <td align="center"><a href="https://github.com/coryairbhb"><img src="https://avatars.githubusercontent.com/u/50755629?v=4?s=100" width="100px;" alt=""/><br /><sub><b>coryairbhb</b></sub></a><br /><a href="https://github.com/reclosedev/requests-cache/issues?q=author%3Acoryairbhb" title="Bug reports">🐛</a></td>
     <td align="center"><a href="https://github.com/craigls"><img src="https://avatars.githubusercontent.com/u/972350?v=4?s=100" width="100px;" alt=""/><br /><sub><b>craig</b></sub></a><br /><a href="https://github.com/reclosedev/requests-cache/commits?author=craigls" title="Code">💻</a> <a href="https://github.com/reclosedev/requests-cache/issues?q=author%3Acraigls" title="Bug reports">🐛</a></td>
     <td align="center"><a href="https://stackoverflow.com/users/86643/denis"><img src="https://avatars.githubusercontent.com/u/1280390?v=4?s=100" width="100px;" alt=""/><br /><sub><b>denis-bz</b></sub></a><br /><a href="https://github.com/reclosedev/requests-cache/issues?q=author%3Adenis-bz" title="Bug reports">🐛</a></td>
-    <td align="center"><a href="https://gir.st/"><img src="https://avatars.githubusercontent.com/u/11820748?v=4?s=100" width="100px;" alt=""/><br /><sub><b>girst</b></sub></a><br /><a href="https://github.com/reclosedev/requests-cache/issues?q=author%3Agirst" title="Bug reports">🐛</a></td>
   </tr>
   <tr>
+    <td align="center"><a href="https://gir.st/"><img src="https://avatars.githubusercontent.com/u/11820748?v=4?s=100" width="100px;" alt=""/><br /><sub><b>girst</b></sub></a><br /><a href="https://github.com/reclosedev/requests-cache/issues?q=author%3Agirst" title="Bug reports">🐛</a></td>
     <td align="center"><a href="https://github.com/gorogoroumaru"><img src="https://avatars.githubusercontent.com/u/30716350?v=4?s=100" width="100px;" alt=""/><br /><sub><b>gorogoroumaru</b></sub></a><br /><a href="https://github.com/reclosedev/requests-cache/commits?author=gorogoroumaru" title="Code">💻</a></td>
     <td align="center"><a href="https://github.com/harvey251"><img src="https://avatars.githubusercontent.com/u/33844174?v=4?s=100" width="100px;" alt=""/><br /><sub><b>harvey251</b></sub></a><br /><a href="https://github.com/reclosedev/requests-cache/issues?q=author%3Aharvey251" title="Bug reports">🐛</a></td>
     <td align="center"><a href="https://github.com/mbarkhau"><img src="https://avatars.githubusercontent.com/u/446561?v=4?s=100" width="100px;" alt=""/><br /><sub><b>mbarkhau</b></sub></a><br /><a href="https://github.com/reclosedev/requests-cache/commits?author=mbarkhau" title="Code">💻</a> <a href="https://github.com/reclosedev/requests-cache/commits?author=mbarkhau" title="Tests">⚠️</a> <a href="#infra-mbarkhau" title="Infrastructure (Hosting, Build-Tools, etc)">🚇</a> <a href="https://github.com/reclosedev/requests-cache/issues?q=author%3Ambarkhau" title="Bug reports">🐛</a></td>
diff --git a/HISTORY.md b/HISTORY.md
index 1d80b30..7a4027a 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -1,9 +1,10 @@
 # History
 
 ## 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)`
+* Fix serialization in filesystem backend with binary content that is also valid UTF-8
+* Fix some regression bugs introduced in 0.9.0:
+  * Add support for `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)
diff --git a/docs/user_guide/serializers.md b/docs/user_guide/serializers.md
index 2e3621e..b2bae92 100644
--- a/docs/user_guide/serializers.md
+++ b/docs/user_guide/serializers.md
@@ -113,10 +113,13 @@ For example, a compressed pickle serializer can be built as:
 ```python
 >>> import gzip
 >>> from requests_cache import CachedSession, SerializerPipeline, Stage, pickle_serializer
->>> compressed_serializer = SerializerPipeline([
-...     pickle_serializer,
-...     Stage(dumps=gzip.compress, loads=gzip.decompress),
-... ])
+>>> compressed_serializer = SerializerPipeline(
+...     [
+...         pickle_serializer,
+...         Stage(dumps=gzip.compress, loads=gzip.decompress),
+...     ],
+...     is_binary=True,
+... )
 >>> session = CachedSession(serializer=compressed_serializer)
 ```
 :::
diff --git a/requests_cache/backends/filesystem.py b/requests_cache/backends/filesystem.py
index b5da0df..c94b662 100644
--- a/requests_cache/backends/filesystem.py
+++ b/requests_cache/backends/filesystem.py
@@ -96,7 +96,7 @@ class FileDict(BaseStorage):
         super().__init__(**kwargs)
         self.cache_dir = get_cache_path(cache_name, use_cache_dir=use_cache_dir, use_temp=use_temp)
         self.extension = _get_extension(extension, self.serializer)
-        self.is_binary = False
+        self.is_binary = getattr(self.serializer, 'is_binary', False)
         makedirs(self.cache_dir, exist_ok=True)
 
     @contextmanager
@@ -114,24 +114,16 @@ class FileDict(BaseStorage):
     def __getitem__(self, key):
         mode = 'rb' if self.is_binary else 'r'
         with self._try_io():
-            try:
-                with self._path(key).open(mode) as f:
-                    return self.serializer.loads(f.read())
-            except UnicodeDecodeError:
-                self.is_binary = True
-                return self.__getitem__(key)
+            with self._path(key).open(mode) as f:
+                return self.serializer.loads(f.read())
 
     def __delitem__(self, key):
         with self._try_io():
             self._path(key).unlink()
 
     def __setitem__(self, key, value):
-        serialized_value = self.serializer.dumps(value)
-        if isinstance(serialized_value, bytes):
-            self.is_binary = True
-        mode = 'wb' if self.is_binary else 'w'
         with self._try_io():
-            with self._path(key).open(mode) as f:
+            with self._path(key).open(mode='wb' if self.is_binary else 'w') as f:
                 f.write(self.serializer.dumps(value))
 
     def __iter__(self):
diff --git a/requests_cache/serializers/pipeline.py b/requests_cache/serializers/pipeline.py
index 3bbfbda..2a22761 100644
--- a/requests_cache/serializers/pipeline.py
+++ b/requests_cache/serializers/pipeline.py
@@ -3,7 +3,7 @@
    :classes-only:
    :nosignatures:
 """
-from typing import Any, Callable, List, Union
+from typing import Any, Callable, Sequence, Union
 
 from ..models import CachedResponse
 
@@ -29,22 +29,26 @@ class Stage:
 
 
 class SerializerPipeline:
-    """A sequence of steps used to serialize and deserialize response objects.
-    This can be initialized with :py:class:`Stage` objects, or any objects with ``dumps()`` and
-    ``loads()`` methods
+    """A pipeline of stages chained together to serialize and deserialize response objects.
+
+    Args:
+        stages: A sequence of :py:class:`Stage` objects, or any objects with ``dumps()`` and
+            ``loads()`` methods
+        is_binary: Indicates whether the serialized content is binary
     """
 
-    def __init__(self, stages: List):
-        self.steps = stages
-        self.dump_steps = [step.dumps for step in stages]
-        self.load_steps = [step.loads for step in reversed(stages)]
+    def __init__(self, stages: Sequence, is_binary: bool = False):
+        self.is_binary = is_binary
+        self.stages = stages
+        self.dump_stages = [stage.dumps for stage in stages]
+        self.load_stages = [stage.loads for stage in reversed(stages)]
 
     def dumps(self, value) -> Union[str, bytes]:
-        for step in self.dump_steps:
+        for step in self.dump_stages:
             value = step(value)
         return value
 
     def loads(self, value) -> CachedResponse:
-        for step in self.load_steps:
+        for step in self.load_stages:
             value = step(value)
         return value
diff --git a/requests_cache/serializers/preconf.py b/requests_cache/serializers/preconf.py
index 6cf83bc..35453b5 100644
--- a/requests_cache/serializers/preconf.py
+++ b/requests_cache/serializers/preconf.py
@@ -34,7 +34,9 @@ orjson_preconf_stage = CattrStage(orjson.make_converter)  #: Pre-serialization s
 yaml_preconf_stage = CattrStage(pyyaml.make_converter)  #: Pre-serialization steps for YAML
 toml_preconf_stage = CattrStage(tomlkit.make_converter)  #: Pre-serialization steps for TOML
 ujson_preconf_stage = CattrStage(ujson.make_converter)  #: Pre-serialization steps for ultrajson
-pickle_serializer = SerializerPipeline([base_stage, pickle])  #: Complete pickle serializer
+pickle_serializer = SerializerPipeline(
+    [base_stage, pickle], is_binary=True
+)  #: Complete pickle serializer
 utf8_encoder = Stage(dumps=str.encode, loads=lambda x: x.decode())  #: Encode to bytes
 
 
@@ -55,7 +57,9 @@ try:
         """Create a serializer that uses ``pickle`` + ``itsdangerous`` to add a signature to
         responses on write, and validate that signature with a secret key on read.
         """
-        return SerializerPipeline([base_stage, pickle, signer_stage(secret_key, salt)])
+        return SerializerPipeline(
+            [base_stage, pickle, signer_stage(secret_key, salt)], is_binary=True
+        )
 
 except ImportError as e:
     signer_stage = get_placeholder_class(e)
@@ -70,8 +74,8 @@ try:
         import bson
 
     bson_serializer = SerializerPipeline(
-        [bson_preconf_stage, bson]
-    )  #: Complete BSON serializer; using pymongo's ``bson.json_util`` if installed, otherwise standalone ``bson`` codec
+        [bson_preconf_stage, bson], is_binary=False
+    )  #: Complete BSON serializer; uses pymongo's ``bson.json_util`` if installed, otherwise standalone ``bson`` codec
 except ImportError as e:
     bson_serializer = get_placeholder_class(e)
 
@@ -88,7 +92,7 @@ except ImportError:
 
 _json_stage = Stage(dumps=partial(json.dumps, indent=2), loads=json.loads)
 json_serializer = SerializerPipeline(
-    [_json_preconf_stage, _json_stage]
+    [_json_preconf_stage, _json_stage], is_binary=False
 )  #: Complete JSON serializer; uses ultrajson if available
 
 
@@ -100,7 +104,8 @@ try:
         [
             yaml_preconf_stage,
             Stage(yaml, loads='safe_load', dumps='safe_dump'),
-        ]
+        ],
+        is_binary=False,
     )  #: Complete YAML serializer
 except ImportError as e:
     yaml_serializer = get_placeholder_class(e)
diff --git a/tests/integration/test_filesystem.py b/tests/integration/test_filesystem.py
index 3707f20..4a4884e 100644
--- a/tests/integration/test_filesystem.py
+++ b/tests/integration/test_filesystem.py
@@ -1,4 +1,3 @@
-import pickle
 from shutil import rmtree
 from tempfile import gettempdir
 
@@ -20,7 +19,7 @@ class TestFileDict(BaseStorageTest):
         rmtree(CACHE_NAME, ignore_errors=True)
 
     def init_cache(self, index=0, clear=True, **kwargs):
-        cache = FileDict(f'{CACHE_NAME}_{index}', serializer=pickle, use_temp=True, **kwargs)
+        cache = FileDict(f'{CACHE_NAME}_{index}', serializer='pickle', use_temp=True, **kwargs)
         if clear:
             cache.clear()
         return cache
diff --git a/tests/unit/test_serializers.py b/tests/unit/test_serializers.py
index bf776fd..80d0f3a 100644
--- a/tests/unit/test_serializers.py
+++ b/tests/unit/test_serializers.py
@@ -68,7 +68,7 @@ def test_optional_dependencies():
 def test_cache_signing(tempfile_path):
     serializer = safe_pickle_serializer(secret_key=str(uuid4()))
     session = CachedSession(tempfile_path, serializer=serializer)
-    assert isinstance(session.cache.responses.serializer.steps[-1].obj, Signer)
+    assert isinstance(session.cache.responses.serializer.stages[-1].obj, Signer)
 
     # Simple serialize/deserialize round trip
     response = CachedResponse()