From 29cc2a3e8ecdfbf9b8546a589e3a9acfbda08095 Mon Sep 17 00:00:00 2001
From: Ishaan Kapur <64529428+ishaanlabs-gg@users.noreply.github.com>
Date: Thu, 2 Jul 2026 21:44:59 +0530
Subject: [PATCH] Fix pytest 9.1 monkeypatch sentinel imports

---
 src/flask/cli.py         | 13 ++++++++++++-
 tests/conftest.py        | 16 ++++++++++------
 tests/test_blueprints.py |  7 ++++++-
 tests/test_cli.py        | 11 ++++++++---
 tests/test_views.py      |  7 ++++++-
 5 files changed, 42 insertions(+), 12 deletions(-)

diff --git a/src/flask/cli.py b/src/flask/cli.py
index 1a9159ec7c..bd8845138f 100644
--- a/src/flask/cli.py
+++ b/src/flask/cli.py
@@ -777,7 +777,18 @@ def show_server_banner(debug: bool, app_import_path: str | None) -> None:
         click.echo(f" * Debug mode: {'on' if debug else 'off'}")
 
 
-class CertParamType(click.ParamType[t.Any]):
+if t.TYPE_CHECKING:
+
+    class _CertParamTypeBase(click.ParamType[t.Any]):
+        pass
+
+else:
+
+    class _CertParamTypeBase(click.ParamType):
+        pass
+
+
+class CertParamType(_CertParamTypeBase):
     """Click option type for the ``--cert`` option. Allows either an
     existing file, the string ``'adhoc'``, or an import for a
     :class:`~ssl.SSLContext` object.
diff --git a/tests/conftest.py b/tests/conftest.py
index 0414b9e22f..913f63ae57 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -7,6 +7,10 @@
 from flask import Flask
 from flask.globals import app_ctx as _app_ctx
 
+_MONKEYPATCH_NOTSET = (
+    monkeypatch.NOTSET if hasattr(monkeypatch, "NOTSET") else monkeypatch.notset
+)
+
 
 @pytest.fixture(scope="session", autouse=True)
 def _standard_os_environ():
@@ -16,15 +20,15 @@ def _standard_os_environ():
     """
     mp = monkeypatch.MonkeyPatch()
     out = (
-        (os.environ, "FLASK_ENV_FILE", monkeypatch.notset),
-        (os.environ, "FLASK_APP", monkeypatch.notset),
-        (os.environ, "FLASK_DEBUG", monkeypatch.notset),
-        (os.environ, "FLASK_RUN_FROM_CLI", monkeypatch.notset),
-        (os.environ, "WERKZEUG_RUN_MAIN", monkeypatch.notset),
+        (os.environ, "FLASK_ENV_FILE", _MONKEYPATCH_NOTSET),
+        (os.environ, "FLASK_APP", _MONKEYPATCH_NOTSET),
+        (os.environ, "FLASK_DEBUG", _MONKEYPATCH_NOTSET),
+        (os.environ, "FLASK_RUN_FROM_CLI", _MONKEYPATCH_NOTSET),
+        (os.environ, "WERKZEUG_RUN_MAIN", _MONKEYPATCH_NOTSET),
     )
 
     for _, key, value in out:
-        if value is monkeypatch.notset:
+        if value is _MONKEYPATCH_NOTSET:
             mp.delenv(key, False)
         else:
             mp.setenv(key, value)
diff --git a/tests/test_blueprints.py b/tests/test_blueprints.py
index 6eb7d1d521..dc93f8faaa 100644
--- a/tests/test_blueprints.py
+++ b/tests/test_blueprints.py
@@ -1,6 +1,11 @@
 import pytest
 from jinja2 import TemplateNotFound
-from werkzeug.http import parse_cache_control_header
+from werkzeug.datastructures.cache_control import ResponseCacheControl
+
+if hasattr(ResponseCacheControl, "from_header"):
+    parse_cache_control_header = ResponseCacheControl.from_header
+else:
+    from werkzeug.http import parse_cache_control_header
 
 import flask
 
diff --git a/tests/test_cli.py b/tests/test_cli.py
index 2a34088bd5..2673bb412a 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -11,7 +11,7 @@
 
 import click
 import pytest
-from _pytest.monkeypatch import notset
+from _pytest import monkeypatch as _pytest_monkeypatch
 from click.testing import CliRunner
 
 from flask import Blueprint
@@ -31,6 +31,11 @@
 
 cwd = Path.cwd()
 test_path = (Path(__file__) / ".." / "test_apps").resolve()
+_MONKEYPATCH_NOTSET = (
+    _pytest_monkeypatch.NOTSET
+    if hasattr(_pytest_monkeypatch, "NOTSET")
+    else _pytest_monkeypatch.notset
+)
 
 
 @pytest.fixture
@@ -537,7 +542,7 @@ def dotenv_not_available():
 def test_load_dotenv(monkeypatch):
     # can't use monkeypatch.delitem since the keys don't exist yet
     for item in ("FOO", "BAR", "SPAM", "HAM"):
-        monkeypatch._setitem.append((os.environ, item, notset))
+        monkeypatch._setitem.append((os.environ, item, _MONKEYPATCH_NOTSET))
 
     monkeypatch.setenv("EGGS", "3")
     monkeypatch.chdir(test_path)
@@ -560,7 +565,7 @@ def test_load_dotenv(monkeypatch):
 @need_dotenv
 def test_dotenv_path(monkeypatch):
     for item in ("FOO", "BAR", "EGGS"):
-        monkeypatch._setitem.append((os.environ, item, notset))
+        monkeypatch._setitem.append((os.environ, item, _MONKEYPATCH_NOTSET))
 
     load_dotenv(test_path / ".flaskenv")
     assert Path.cwd() == cwd
diff --git a/tests/test_views.py b/tests/test_views.py
index d002b50439..2cfa30af3d 100644
--- a/tests/test_views.py
+++ b/tests/test_views.py
@@ -1,5 +1,10 @@
 import pytest
-from werkzeug.http import parse_set_header
+from werkzeug.datastructures import HeaderSet
+
+if hasattr(HeaderSet, "from_header"):
+    parse_set_header = HeaderSet.from_header
+else:
+    from werkzeug.http import parse_set_header
 
 import flask.views
 from flask.testing import FlaskClient