Updated script that can be controled by Nodejs web app

lib/python3.13/site-packages/greenlet/tests/fail_slp_switch.py

@@ -0,0 +1,29 @@
+# -*- coding: utf-8 -*-
+"""
+A test helper for seeing what happens when slp_switch()
+fails.
+"""
+# pragma: no cover
+
+import greenlet
+
+
+print('fail_slp_switch is running', flush=True)
+
+runs = []
+def func():
+    runs.append(1)
+    greenlet.getcurrent().parent.switch()
+    runs.append(2)
+    greenlet.getcurrent().parent.switch()
+    runs.append(3)
+
+g = greenlet._greenlet.UnswitchableGreenlet(func)
+g.switch()
+assert runs == [1]
+g.switch()
+assert runs == [1, 2]
+g.force_slp_switch_error = True
+
+# This should crash.
+g.switch()