Update json for Flask 2.3 (#1582)

* Update json for Flask 2.3

* Update docstrings

connexion/apps/flask_app.py

@@ -2,16 +2,16 @@
 This module defines a FlaskApp, a Connexion application to wrap a Flask application.
 """
 
-import datetime
 import logging
 import pathlib
-from decimal import Decimal
 from types import FunctionType  # NOQA
 
 import a2wsgi
 import flask
 import werkzeug.exceptions
-from flask import json, signals
+from flask import signals
+
+from connexion import jsonifier
 
 from ..apis.flask_api import FlaskApi
 from ..exceptions import ProblemException
@@ -36,7 +36,7 @@ def __init__(self, import_name, server="flask", extra_files=None, **kwargs):
 
     def create_app(self):
         app = flask.Flask(self.import_name, **self.server_args)
-        app.json_encoder = FlaskJSONEncoder
+        app.json = FlaskJSONProvider(app)
         app.url_map.converters["float"] = NumberConverter
         app.url_map.converters["int"] = IntegerConverter
         return app
@@ -183,24 +183,12 @@ def __call__(self, scope, receive, send):  # pragma: no cover
         return self.middleware(scope, receive, send)
 
 
-class FlaskJSONEncoder(json.JSONEncoder):
+class FlaskJSONProvider(flask.json.provider.DefaultJSONProvider):
+    """Custom JSONProvider which adds connexion defaults on top of Flask's"""
+
+    @jsonifier.wrap_default
     def default(self, o):
-        if isinstance(o, datetime.datetime):
-            if o.tzinfo:
-                # eg: '2015-09-25T23:14:42.588601+00:00'
-                return o.isoformat("T")
-            else:
-                # No timezone present - assume UTC.
-                # eg: '2015-09-25T23:14:42.588601Z'
-                return o.isoformat("T") + "Z"
-
-        if isinstance(o, datetime.date):
-            return o.isoformat()
-
-        if isinstance(o, Decimal):
-            return float(o)
-
-        return json.JSONEncoder.default(self, o)
+        return super().default(o)
 
 
 class NumberConverter(werkzeug.routing.BaseConverter):

connexion/jsonifier.py

@@ -3,21 +3,26 @@
 """
 
 import datetime
+import functools
 import json
+import typing as t
 import uuid
+from decimal import Decimal
 
 
-class JSONEncoder(json.JSONEncoder):
-    """The default Connexion JSON encoder. Handles extra types compared to the
+def wrap_default(default_fn: t.Callable) -> t.Callable:
+    """The Connexion defaults for JSON encoding. Handles extra types compared to the
     built-in :class:`json.JSONEncoder`.
 
     -   :class:`datetime.datetime` and :class:`datetime.date` are
         serialized to :rfc:`822` strings. This is the same as the HTTP
         date format.
+    -   :class:`decimal.Decimal` is serialized to a float.
     -   :class:`uuid.UUID` is serialized to a string.
     """
 
-    def default(self, o):
+    @functools.wraps(default_fn)
+    def wrapped_default(self, o):
         if isinstance(o, datetime.datetime):
             if o.tzinfo:
                 # eg: '2015-09-25T23:14:42.588601+00:00'
@@ -30,10 +35,25 @@ def default(self, o):
         if isinstance(o, datetime.date):
             return o.isoformat()
 
+        if isinstance(o, Decimal):
+            return float(o)
+
         if isinstance(o, uuid.UUID):
             return str(o)
 
-        return json.JSONEncoder.default(self, o)
+        return default_fn(o)
+
+    return wrapped_default
+
+
+class JSONEncoder(json.JSONEncoder):
+    """The default Connexion JSON encoder. Handles extra types compared to the
+    built-in :class:`json.JSONEncoder`.
+    """
+
+    @wrap_default
+    def default(self, o):
+        return super().default(o)
 
 
 class Jsonifier:
@@ -48,6 +68,7 @@ def __init__(self, json_=json, **kwargs):
         """
         self.json = json_
         self.dumps_args = kwargs
+        self.dumps_args.setdefault("cls", JSONEncoder)
 
     def dumps(self, data, **kwargs):
         """Central point where JSON serialization happens inside

connexion/middleware/swagger_ui.py

@@ -12,7 +12,6 @@
 from starlette.types import ASGIApp, Receive, Scope, Send
 
 from connexion.apis import AbstractSwaggerUIAPI
-from connexion.jsonifier import JSONEncoder, Jsonifier
 from connexion.middleware import AppMiddleware
 from connexion.utils import yamldumper
 
@@ -207,7 +206,3 @@ async def _get_swagger_ui_config(self, request):
             media_type="application/json",
             content=self.jsonifier.dumps(self.options.openapi_console_ui_config),
         )
-
-    @classmethod
-    def _set_jsonifier(cls):
-        cls.jsonifier = Jsonifier(cls=JSONEncoder)

setup.py

@@ -25,15 +25,15 @@ def read_version(package):
     'PyYAML>=5.1,<7',
     'requests>=2.27,<3',
     'inflection>=0.3.1,<0.6',
-    'werkzeug>=2,<3',
+    'werkzeug>=2.2.1,<3',
     'starlette>=0.15,<1',
     'httpx>=0.15,<1',
 ]
 
 swagger_ui_require = 'swagger-ui-bundle>=0.0.2,<0.1'
 
 flask_require = [
-    'flask>=2,<3',
+    'flask>=2.2,<3',
     'a2wsgi>=1.4,<2',
 ]
 

tests/api/test_responses.py

@@ -2,7 +2,7 @@
 from struct import unpack
 
 import yaml
-from connexion.apps.flask_app import FlaskJSONEncoder
+from connexion.apps.flask_app import FlaskJSONProvider
 from werkzeug.test import Client, EnvironBuilder
 
 
@@ -279,15 +279,15 @@ def test_nested_additional_properties(simple_openapi_app):
     assert response == {"nested": {"object": True}}
 
 
-def test_custom_encoder(simple_app):
-    class CustomEncoder(FlaskJSONEncoder):
+def test_custom_provider(simple_app):
+    class CustomProvider(FlaskJSONProvider):
         def default(self, o):
             if o.__class__.__name__ == "DummyClass":
                 return "cool result"
-            return FlaskJSONEncoder.default(self, o)
+            return super().default(o)
 
     flask_app = simple_app.app
-    flask_app.json_encoder = CustomEncoder
+    flask_app.json = CustomProvider(flask_app)
     app_client = flask_app.test_client()
 
     resp = app_client.get("/v1.0/custom-json-response")

tests/test_flask_encoder.py

@@ -4,39 +4,42 @@
 from decimal import Decimal
 
 import pytest
-from connexion.apps.flask_app import FlaskJSONEncoder
+from connexion.apps.flask_app import FlaskJSONProvider
 
 from conftest import build_app_from_fixture
 
 SPECS = ["swagger.yaml", "openapi.yaml"]
 
 
-def test_json_encoder():
-    s = json.dumps({1: 2}, cls=FlaskJSONEncoder)
+def test_json_encoder(simple_app):
+    flask_app = simple_app.app
+
+    s = FlaskJSONProvider(flask_app).dumps({1: 2})
     assert '{"1": 2}' == s
 
-    s = json.dumps(datetime.date.today(), cls=FlaskJSONEncoder)
+    s = FlaskJSONProvider(flask_app).dumps(datetime.date.today())
     assert len(s) == 12
 
-    s = json.dumps(datetime.datetime.utcnow(), cls=FlaskJSONEncoder)
+    s = FlaskJSONProvider(flask_app).dumps(datetime.datetime.utcnow())
     assert s.endswith('Z"')
 
-    s = json.dumps(Decimal(1.01), cls=FlaskJSONEncoder)
+    s = FlaskJSONProvider(flask_app).dumps(Decimal(1.01))
     assert s == "1.01"
 
-    s = json.dumps(math.expm1(1e-10), cls=FlaskJSONEncoder)
+    s = FlaskJSONProvider(flask_app).dumps(math.expm1(1e-10))
     assert s == "1.00000000005e-10"
 
 
-def test_json_encoder_datetime_with_timezone():
+def test_json_encoder_datetime_with_timezone(simple_app):
     class DummyTimezone(datetime.tzinfo):
         def utcoffset(self, dt):
             return datetime.timedelta(0)
 
         def dst(self, dt):
             return datetime.timedelta(0)
 
-    s = json.dumps(datetime.datetime.now(DummyTimezone()), cls=FlaskJSONEncoder)
+    flask_app = simple_app.app
+    s = FlaskJSONProvider(flask_app).dumps(datetime.datetime.now(DummyTimezone()))
     assert s.endswith('+00:00"')