Flask 2.2.x doesn't allow to load multiple app at the same time.

[Natim]

How to reproduce

app1 = Flask(name)
app2 = Flask(name)

with app1.test_client() as app1_client, app2.test_client() as app2_client:
    login_resp = app1_client.post(
        "/login",
        data={
            "email": email,
            "password": password,
        },)

    app2_client.cookie_jar = app1_client.cookie_jar

    res = app2_client.get("/v1/me")
    assert res.status_code == 200

Running this code raises a LookupError: <ContextVar name='flask.request_ctx' at 0x7faa98896de0>

../venv/lib/python3.10/site-packages/flask/ctx.py:399: in pop
    self.app.do_teardown_request(exc)
../venv/lib/python3.10/site-packages/flask/app.py:2370: in do_teardown_request
    for name in chain(request.blueprints, (None,)):
../venv/lib/python3.10/site-packages/werkzeug/local.py:316: in __get__
    obj = instance._get_current_object()  # type: ignore[misc]
../venv/lib/python3.10/site-packages/werkzeug/local.py:509: in _get_current_object
    raise RuntimeError(unbound_message) from None
E   RuntimeError: Working outside of request context.
E   
E   This typically means that you attempted to use functionality that needed
E   an active HTTP request. Consult the documentation on testing for
E   information about how to avoid this problem.

During handling of the above exception, another exception occurred:
.... in test_login:
    with app1.test_client() as app1_client, app2.test_client() as app2_client:
./venv/lib/python3.10/site-packages/flask/testing.py:250: in __exit__
    self._context_stack.close()
/usr/local/lib/python3.10/contextlib.py:584: in close
    self.__exit__(None, None, None)
/usr/local/lib/python3.10/contextlib.py:576: in __exit__
    raise exc_details[1]
/usr/local/lib/python3.10/contextlib.py:561: in __exit__
    if cb(*exc_details):
../venv/lib/python3.10/site-packages/flask/ctx.py:432: in __exit__
    self.pop(exc_value)
../venv/lib/python3.10/site-packages/flask/ctx.py:405: in pop
    ctx = _cv_request.get()
E   LookupError: <ContextVar name='flask.request_ctx' at 0x7faa98896de0>

Going back to Flask 2.1.3 fixes the issue.

Environment:

• Python version: 3.10.4
• Flask version: 2.2.2

[davidism]

I see what you're trying to do, but I'm not sure how this ever would have worked correctly (even if it appeared to work previously). The test is running in one thread. You're opening two apps, that should have different preserved contexts, in the same thread, so there is only one context.

Instead, you should open each client context separately, and only for exactly how long you need it. In the example shown, you don't need to preserve contexts for either client, so you can remove the with block.