RAHHH

backend/lib/python3.12/site-packages/twisted/internet/test/test_default.py

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+# Copyright (c) Twisted Matrix Laboratories.
+# See LICENSE for details.
+
+"""
+Tests for L{twisted.internet.default}.
+"""
+from __future__ import annotations
+
+import select
+import sys
+from typing import Callable
+
+from twisted.internet import default
+from twisted.internet.default import _getInstallFunction, install
+from twisted.internet.interfaces import IReactorCore
+from twisted.internet.test.test_main import NoReactor
+from twisted.python.reflect import requireModule
+from twisted.python.runtime import Platform
+from twisted.trial.unittest import SynchronousTestCase
+
+unix = Platform("posix", "other")
+linux = Platform("posix", "linux2")
+windows = Platform("nt", "win32")
+osx = Platform("posix", "darwin")
+
+
+class PollReactorTests(SynchronousTestCase):
+    """
+    Tests for the cases of L{twisted.internet.default._getInstallFunction}
+    in which it picks the poll(2) or epoll(7)-based reactors.
+    """
+
+    def assertIsPoll(self, install: Callable[..., object]) -> None:
+        """
+        Assert the given function will install the poll() reactor, or select()
+        if poll() is unavailable.
+        """
+        if hasattr(select, "poll"):
+            self.assertEqual(install.__module__, "twisted.internet.pollreactor")
+        else:
+            self.assertEqual(install.__module__, "twisted.internet.selectreactor")
+
+    def test_unix(self) -> None:
+        """
+        L{_getInstallFunction} chooses the poll reactor on arbitrary Unix
+        platforms, falling back to select(2) if it is unavailable.
+        """
+        install = _getInstallFunction(unix)
+        self.assertIsPoll(install)
+
+    def test_linux(self) -> None:
+        """
+        L{_getInstallFunction} chooses the epoll reactor on Linux, or poll if
+        epoll is unavailable.
+        """
+        install = _getInstallFunction(linux)
+        if requireModule("twisted.internet.epollreactor") is None:
+            self.assertIsPoll(install)
+        else:
+            self.assertEqual(install.__module__, "twisted.internet.epollreactor")
+
+
+class SelectReactorTests(SynchronousTestCase):
+    """
+    Tests for the cases of L{twisted.internet.default._getInstallFunction}
+    in which it picks the select(2)-based reactor.
+    """
+
+    def test_osx(self) -> None:
+        """
+        L{_getInstallFunction} chooses the select reactor on macOS.
+        """
+        install = _getInstallFunction(osx)
+        self.assertEqual(install.__module__, "twisted.internet.selectreactor")
+
+    def test_windows(self) -> None:
+        """
+        L{_getInstallFunction} chooses the select reactor on Windows.
+        """
+        install = _getInstallFunction(windows)
+        self.assertEqual(install.__module__, "twisted.internet.selectreactor")
+
+
+class InstallationTests(SynchronousTestCase):
+    """
+    Tests for actual installation of the reactor.
+    """
+
+    def test_install(self) -> None:
+        """
+        L{install} installs a reactor.
+        """
+        with NoReactor():
+            install()
+            self.assertIn("twisted.internet.reactor", sys.modules)
+
+    def test_reactor(self) -> None:
+        """
+        Importing L{twisted.internet.reactor} installs the default reactor if
+        none is installed.
+        """
+        installed: list[bool] = []
+
+        def installer() -> object:
+            installed.append(True)
+            return install()
+
+        self.patch(default, "install", installer)
+
+        with NoReactor():
+            from twisted.internet import reactor
+
+            self.assertTrue(IReactorCore.providedBy(reactor))
+            self.assertEqual(installed, [True])