Use Flask test client's own environ dict if available (Fixes #2142)

Author: miguelgrinberg

pyproject.toml

@@ -12,9 +12,9 @@ classifiers = [
     "License :: OSI Approved :: MIT License",
     "Operating System :: OS Independent",
 ]
-requires-python = ">=3.6"
+requires-python = ">=3.8"
 dependencies = [
-    "Flask >= 0.9",
+    "Flask >= 2.1.0",
     "python-socketio >= 5.12.0",
 ]
 
@@ -30,6 +30,12 @@ Homepage = "https://github.com/miguelgrinberg/flask-socketio"
 docs = [
     "sphinx",
 ]
+dev = [
+    "tox",
+    "pytest",
+    "pytest-cov",
+    "redis",
+]
 
 [tool.setuptools]
 zip-safe = false

src/flask_socketio/test_client.py

@@ -2,7 +2,7 @@
 
 from socketio import packet
 from socketio.pubsub_manager import PubSubManager
-from werkzeug.test import EnvironBuilder
+from flask.testing import EnvironBuilder
 
 
 class SocketIOTestClient:
@@ -128,8 +128,16 @@ def connect(self, namespace=None, query_string=None, headers=None,
             if query_string[0] != '?':
                 query_string = '?' + query_string
             url += query_string
-        environ = EnvironBuilder(url, headers=headers).get_environ()
+        if self.flask_test_client:
+            # let Flask's test client build an environ dictionary
+            req = self.flask_test_client._request_from_builder_args(
+                args=(), kwargs={'path': url, 'headers': headers})
+            environ = req.environ
+        else:
+            environ = EnvironBuilder(
+                self.app, path=url, headers=headers).get_environ()
         environ['flask.app'] = self.app
+
         if self.flask_test_client:
             # inject cookies from Flask
             if hasattr(self.flask_test_client, '_add_cookies_to_wsgi'):