Fix loading cached JSON content when decode_content=True and the root element is a list

5 files changed, 35 insertions, 6 deletions

diff --git a/HISTORY.md b/HISTORY.md
index 968a957..0f703a6 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -5,6 +5,7 @@
 
 ## 1.0.2 (2023-TBD)
 * Revert normalizing `CachedResponse.url` so it matches the original request URL
+* Fix loading cached JSON content when `decode_content=True` and the root element is a list
 
 ## 1.0.1 (2023-03-24)
 * Ignore `Cache-Control: must-revalidate` and `no-cache` response headers with `cache_control=False`
diff --git a/requests_cache/models/response.py b/requests_cache/models/response.py
index 2cd6047..134d04b 100755
--- a/requests_cache/models/response.py
+++ b/requests_cache/models/response.py
@@ -18,7 +18,7 @@ if TYPE_CHECKING:
     from ..policy.actions import CacheActions
 
 DATETIME_FORMAT = '%Y-%m-%d %H:%M:%S %Z'  # Format used for __str__ only
-DecodedContent = Union[Dict, str, None]
+DecodedContent = Union[Dict, List, str, None]
 logger = getLogger(__name__)
 
 
diff --git a/requests_cache/serializers/cattrs.py b/requests_cache/serializers/cattrs.py
index bf45c2d..439463e 100644
--- a/requests_cache/serializers/cattrs.py
+++ b/requests_cache/serializers/cattrs.py
@@ -109,9 +109,12 @@ def init_converter(
     converter.register_structure_hook(
         CaseInsensitiveDict, lambda obj, cls: CaseInsensitiveDict(obj)
     )
-    # Convert decoded JSON body back to string
+
+    # Convert decoded JSON body back to a string. If the object is a valid JSON root (dict or list),
+    # that means it was previously saved in human-readable format due to `decode_content=True`.
+    # After this hook runs, the body will also be re-encoded with `_encode_content()`.
     converter.register_structure_hook(
-        DecodedContent, lambda obj, cls: json.dumps(obj) if isinstance(obj, dict) else obj
+        DecodedContent, lambda obj, cls: json.dumps(obj) if isinstance(obj, (dict, list)) else obj
     )
 
     # Resolve forward references (required for CachedResponse.history)
@@ -157,7 +160,9 @@ def _decode_content(response: CachedResponse, response_dict: Dict) -> Dict:
 
 
 def _encode_content(response: CachedResponse) -> CachedResponse:
-    """Re-encode response body if saved as JSON or text; has no effect for a binary response body"""
+    """Re-encode response body if saved as JSON or text (via ``decode_content=True``).
+    This has no effect for a binary response body.
+    """
     if isinstance(response._decoded_content, str):
         response._content = response._decoded_content.encode('utf-8')
         response._decoded_content = None
diff --git a/tests/conftest.py b/tests/conftest.py
index e4ca8a6..099ddb3 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -82,6 +82,7 @@ MOCKED_URL = 'http+mock://requests-cache.com/text'
 MOCKED_URL_ETAG = 'http+mock://requests-cache.com/etag'
 MOCKED_URL_HTTPS = 'https+mock://requests-cache.com/text'
 MOCKED_URL_JSON = 'http+mock://requests-cache.com/json'
+MOCKED_URL_JSON_LIST = 'http+mock://requests-cache.com/json_list'
 MOCKED_URL_REDIRECT = 'http+mock://requests-cache.com/redirect'
 MOCKED_URL_REDIRECT_TARGET = 'http+mock://requests-cache.com/redirect_target'
 MOCKED_URL_VARY = 'http+mock://requests-cache.com/vary'
@@ -208,6 +209,13 @@ def get_mock_adapter() -> Adapter:
     )
     adapter.register_uri(
         ANY_METHOD,
+        MOCKED_URL_JSON_LIST,
+        headers={'Content-Type': 'application/json'},
+        json=['item_1', 'item_2', {'message': 'mock json response'}],
+        status_code=200,
+    )
+    adapter.register_uri(
+        ANY_METHOD,
         MOCKED_URL_REDIRECT,
         headers={'Content-Type': 'text/plain', 'Location': MOCKED_URL_REDIRECT_TARGET},
         text='mock redirect response',
diff --git a/tests/integration/base_cache_test.py b/tests/integration/base_cache_test.py
index 7801570..3e4d230 100644
--- a/tests/integration/base_cache_test.py
+++ b/tests/integration/base_cache_test.py
@@ -25,12 +25,15 @@ from tests.conftest import (
     HTTPBIN_METHODS,
     HTTPDATE_STR,
     LAST_MODIFIED,
+    MOCKED_URL_JSON,
+    MOCKED_URL_JSON_LIST,
     N_ITERATIONS,
     N_REQUESTS_PER_ITERATION,
     N_WORKERS,
     USE_PYTEST_HTTPBIN,
     assert_delta_approx_equal,
     httpbin,
+    mount_mock_adapter,
     skip_pypy,
 )
 
@@ -259,9 +262,9 @@ class BaseCacheTest:
         assert response.is_expired is False
 
     @pytest.mark.parametrize('stream', [True, False])
-    def test_response_decode(self, stream):
+    def test_decode_gzip_response(self, stream):
         """Test that gzip-compressed raw responses (including streamed responses) can be manually
-        decompressed with decode_content=True
+        decompressed with `decode_content=True`
         """
         session = self.init_session()
         response = session.get(httpbin('gzip'), stream=stream)
@@ -274,6 +277,18 @@ class BaseCacheTest:
         assert b'gzipped' in cached_response.content
         assert b'gzipped' in cached_response.raw.read(None, decode_content=True)
 
+    @pytest.mark.parametrize('decode_content', [True, False])
+    @pytest.mark.parametrize('url', [MOCKED_URL_JSON, MOCKED_URL_JSON_LIST])
+    def test_decode_json_response(self, decode_content, url):
+        """Test that JSON responses (with both dict and list root) are correctly returned from the
+        cache, regardless of `decode_content` setting"""
+        session = self.init_session(decode_content=decode_content)
+        session = mount_mock_adapter(session)
+
+        r1 = session.get(url)
+        r2 = session.get(url)
+        assert r1.json() == r2.json()
+
     def test_multipart_upload(self):
         session = self.init_session()
         session.post(httpbin('post'), files={'file1': BytesIO(b'10' * 1024)})