fix : restore wsgi.input stream after middleware body read so request.get_json() works in views

adiuvare/integrations/flask.py

@@ -1,4 +1,5 @@
 import asyncio
+import io
 import json
 
 from werkzeug.wrappers import Request, Response
@@ -14,14 +15,18 @@ def __init__(self, app, guard, flask_app=None) -> None:
         self._flask = flask_app
 
     def __call__(self, environ, start_response):
+        content_length = int(environ.get("CONTENT_LENGTH") or 0)
+        body_bytes = environ["wsgi.input"].read(content_length) if content_length > 0 else b""
+        environ["wsgi.input"] = io.BytesIO(body_bytes)
+
         req = Request(environ)
         raw_ip = req.headers.get("x-forwarded-for", "")
         ip = raw_ip.split(",", 1)[0].strip() or req.remote_addr or "127.0.0.1"
         route_cfg = self._route_cfg(req)
         if route_cfg.get("exempt"):
             return self._app(environ, start_response)
 
-        body_text = req.get_data(as_text=True)
+        body_text = body_bytes.decode("utf-8", errors="replace")
         query_text = req.query_string.decode("utf-8") if req.query_string else ""
         payload = ctx_payload(body_text, query_text)
 

tests/test_flask.py

@@ -461,4 +461,26 @@ def test_threadsafe_items_returns_all_identities():
 
     assert len(result) == 5
     for i in range(5):
-        assert f"user-{i}" in identities
+        assert f"user-{i}" in identities
+
+
+def test_flask_request_json_readable_after_middleware_inspection():
+
+    app = Flask(__name__)
+    guard = Guard()
+    guard.use(app, framework="flask")
+
+    @app.post("/notes")
+    def create_note():
+        data = request.get_json(silent=True)
+        assert data is not None
+        return jsonify(received=data), 201
+
+    client = app.test_client()
+    res = client.post(
+        "/notes",
+        json={"title": "Shopping List", "body": "milk, bread"},
+        headers={"x-user-id": "u1"},
+    )
+    assert res.status_code == 201
+    assert res.get_json() == {"received": {"title": "Shopping List", "body": "milk, bread"}}