Address PR feedback

Author: vimalloc

flask_jwt_extended/config.py

@@ -11,6 +11,7 @@
 from flask import current_app
 from jwt.algorithms import requires_cryptography
 
+from flask_jwt_extended.json_encoder import get_current_json_encoder
 from flask_jwt_extended.json_encoder import JSONEncoder
 from flask_jwt_extended.typing import ExpiresDelta
 
@@ -284,7 +285,7 @@ def error_msg_key(self) -> str:
 
     @property
     def json_encoder(self) -> Type[JSONEncoder]:
-        return JSONEncoder
+        return get_current_json_encoder(current_app)
 
     @property
     def decode_audience(self) -> Union[str, Iterable[str]]:

flask_jwt_extended/json_encoder.py

@@ -1,12 +1,12 @@
+
 import json
 from typing import Any
 
 
-try:
-    # Flask 2.2 deprecated the flask.json.JSONEncoder (see below), lets recreate
-    # a class with the same semantics as the old JSONEncoder.
+try:  # pragma: no cover
+    from flask.json.provider import DefaultJSONProvider  # type: ignore
 
-    from flask.json.provider import DefaultJSONProvider
+    USING_CUSTOM_ENCODER = True
 
     class JSONEncoder(json.JSONEncoder):
         """The default JSON encoder. Handles extra types compared to the
@@ -32,5 +32,14 @@ def default(self, o: Any) -> Any:
             """
             return DefaultJSONProvider.default(o)
 
-except ModuleNotFoundError:  # pragma: no cover
-    from flask.json import JSONEncoder  # type: ignore  # noqa: F401
+except ModuleNotFoundError:
+    from flask.json import JSONEncoder  # type: ignore
+
+    USING_CUSTOM_ENCODER = False
+
+
+def get_current_json_encoder(current_app):  # pragma: no cover
+    if USING_CUSTOM_ENCODER:
+        return JSONEncoder
+    else:
+        return current_app.json_encoder