feat(redis): add native JSON session storage for 4.1.0

- Add opt-in SESSION_REDIS_JSON storage for asyncio Redis backends.
- Check JSON command support at startup and reject JSON mode on Trio.
- Read legacy strings and migrate sessions on their next save.
- Validate JSON objects before transactional replacement and expiry.
- Preserve tagged serialization for datetime, tuple, and other types.
- Cover command contracts, error handling, and session round-trips.
- Document server requirements, permissions, and migration limits.
- Normalize indentation and whitespace across code, tests, and examples.
- Bump the package and lockfile to 4.1.0 and update the changelog.
- Refresh the locked pycparser dependency to 3.12.

tests/test_session_cookie.py

@@ -2,59 +2,59 @@ import pytest
 from itsdangerous import Signer
 
 def _cookie_value(response, name="session"):
-    header = response.headers.get("Set-Cookie")
-    assert header is not None, "no Set-Cookie header was sent"
-    assert header.startswith(f"{name}=")
-    return header[len(name) + 1:].split(";", 1)[0]
+  header = response.headers.get("Set-Cookie")
+  assert header is not None, "no Set-Cookie header was sent"
+  assert header.startswith(f"{name}=")
+  return header[len(name) + 1:].split(";", 1)[0]
 
 @pytest.mark.asyncio
 async def test_unsigned_cookie_is_plain_sid(app_factory):
-    """Regression: str sid used to blow up with AttributeError on .decode()."""
-    app = app_factory(SESSION_USE_SIGNER=False)
-    client = app.test_client()
+  """Regression: str sid used to blow up with AttributeError on .decode()."""
+  app = app_factory(SESSION_USE_SIGNER=False)
+  client = app.test_client()
 
-    response = await client.get("/")
+  response = await client.get("/")
 
-    assert response.status_code == 200
-    data = await response.get_json()
-    assert data["hits"] == 1
-    assert _cookie_value(response) == data["sid"]
+  assert response.status_code == 200
+  data = await response.get_json()
+  assert data["hits"] == 1
+  assert _cookie_value(response) == data["sid"]
 
 @pytest.mark.asyncio
 async def test_signed_cookie_is_signed_sid(app_factory):
-    app = app_factory(SESSION_USE_SIGNER=True)
-    client = app.test_client()
+  app = app_factory(SESSION_USE_SIGNER=True)
+  client = app.test_client()
 
-    response = await client.get("/")
+  response = await client.get("/")
 
-    assert response.status_code == 200
-    data = await response.get_json()
-    cookie = _cookie_value(response)
-    assert cookie != data["sid"]
+  assert response.status_code == 200
+  data = await response.get_json()
+  cookie = _cookie_value(response)
+  assert cookie != data["sid"]
 
-    signer = Signer(app.secret_key, salt="quart-session",
-                    key_derivation="hmac")
-    assert signer.unsign(cookie).decode() == data["sid"]
+  signer = Signer(app.secret_key, salt="quart-session",
+          key_derivation="hmac")
+  assert signer.unsign(cookie).decode() == data["sid"]
 
 @pytest.mark.asyncio
 @pytest.mark.parametrize("use_signer", [False, True])
 async def test_session_survives_next_request(app_factory, use_signer):
-    app = app_factory(SESSION_USE_SIGNER=use_signer)
-    client = app.test_client()
+  app = app_factory(SESSION_USE_SIGNER=use_signer)
+  client = app.test_client()
 
-    first = await client.get("/")
-    second = await client.get("/")
+  first = await client.get("/")
+  second = await client.get("/")
 
-    assert (await first.get_json())["hits"] == 1
-    assert (await second.get_json())["hits"] == 2
+  assert (await first.get_json())["hits"] == 1
+  assert (await second.get_json())["hits"] == 2
 
 @pytest.mark.asyncio
 async def test_signer_without_secret_key_sets_no_cookie(app_factory):
-    app = app_factory(SESSION_USE_SIGNER=True)
-    app.secret_key = None
-    client = app.test_client()
+  app = app_factory(SESSION_USE_SIGNER=True)
+  app.secret_key = None
+  client = app.test_client()
 
-    response = await client.get("/")
+  response = await client.get("/")
 
-    assert response.status_code == 200
-    assert response.headers.get("Set-Cookie") is None
+  assert response.status_code == 200
+  assert response.headers.get("Set-Cookie") is None