From f1946be8e487d2029b39198fc2ee7e3046ce8a15 Mon Sep 17 00:00:00 2001
From: eeshsaxena <eeshsaxena@gmail.com>
Date: Mon, 20 Jul 2026 07:19:48 +0530
Subject: [PATCH] tests: replace private _pytest.monkeypatch.notset with public
 delenv API

pytest 9.1 removed the notset sentinel from _pytest.monkeypatch, moving
it to _pytest.compat.NOTSET (a private location). Importing from either
private path breaks on pytest 9.1+.

Both usages only needed notset to signal 'delete this env var before the
test runs'. monkeypatch.delenv(key, raising=False) does exactly that using
the stable public API, so drop the sentinel entirely.

tests/conftest.py:
- Remove 'from _pytest import monkeypatch' import.
- Replace notset sentinel tuple with a plain tuple of key names.
- Use pytest.MonkeyPatch() directly (public class).
- _reset_os_environ now calls monkeypatch.delenv() per key instead of
  appending to the private _setitem list.

tests/test_cli.py:
- Remove 'from _pytest.monkeypatch import notset'.
- Replace _setitem.append(..., notset) with monkeypatch.delenv(raising=False)
  in test_load_dotenv and test_dotenv_path.

Fixes #6071
---
 tests/conftest.py | 41 ++++++++++++++++++-----------------------
 tests/test_cli.py |  6 ++----
 2 files changed, 20 insertions(+), 27 deletions(-)

diff --git a/tests/conftest.py b/tests/conftest.py
index 0414b9e22f..aefe3cf54d 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -2,43 +2,38 @@
 import sys
 
 import pytest
-from _pytest import monkeypatch
 
 from flask import Flask
 from flask.globals import app_ctx as _app_ctx
 
+_FLASK_ENV_KEYS = (
+    "FLASK_ENV_FILE",
+    "FLASK_APP",
+    "FLASK_DEBUG",
+    "FLASK_RUN_FROM_CLI",
+    "WERKZEUG_RUN_MAIN",
+)
+
 
 @pytest.fixture(scope="session", autouse=True)
 def _standard_os_environ():
-    """Set up ``os.environ`` at the start of the test session to have
-    standard values. Returns a list of operations that is used by
-    :func:`._reset_os_environ` after each test.
-    """
-    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),
-    )
+    """Remove Flask-related environment variables at the start of the test
+    session so they don't leak in from the developer's shell."""
+    mp = pytest.MonkeyPatch()
 
-    for _, key, value in out:
-        if value is monkeypatch.notset:
-            mp.delenv(key, False)
-        else:
-            mp.setenv(key, value)
+    for key in _FLASK_ENV_KEYS:
+        mp.delenv(key, raising=False)
 
-    yield out
+    yield
     mp.undo()
 
 
 @pytest.fixture(autouse=True)
 def _reset_os_environ(monkeypatch, _standard_os_environ):
-    """Reset ``os.environ`` to the standard environ after each test,
-    in case a test changed something without cleaning up.
-    """
-    monkeypatch._setitem.extend(_standard_os_environ)
+    """Remove Flask-related environment variables before each test in case a
+    previous test set them without cleaning up."""
+    for key in _FLASK_ENV_KEYS:
+        monkeypatch.delenv(key, raising=False)
 
 
 @pytest.fixture
diff --git a/tests/test_cli.py b/tests/test_cli.py
index 2a34088bd5..e605b2b63e 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -11,7 +11,6 @@
 
 import click
 import pytest
-from _pytest.monkeypatch import notset
 from click.testing import CliRunner
 
 from flask import Blueprint
@@ -535,9 +534,8 @@ def dotenv_not_available():
 
 @need_dotenv
 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.delenv(item, raising=False)
 
     monkeypatch.setenv("EGGS", "3")
     monkeypatch.chdir(test_path)
@@ -560,7 +558,7 @@ 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.delenv(item, raising=False)
 
     load_dotenv(test_path / ".flaskenv")
     assert Path.cwd() == cwd