From 565616dc753bb9d863d0e9c1ba4c05c0d9a16369 Mon Sep 17 00:00:00 2001
From: Jean-Paul Calderone <exarkun@twistedmatrix.com>
Date: Thu, 7 Mar 2019 15:04:37 -0500
Subject: [PATCH] Expand functionality of our base TestCase classes

---
 src/allmydata/test/common.py | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/src/allmydata/test/common.py b/src/allmydata/test/common.py
index 30e6b6818..aac08f5bf 100644
--- a/src/allmydata/test/common.py
+++ b/src/allmydata/test/common.py
@@ -1,4 +1,9 @@
 import os, random, struct
+import tempfile
+from tempfile import mktemp
+from functools import partial
+from unittest import case as _case
+
 import treq
 
 from zope.interface import implementer
@@ -845,11 +850,32 @@ class _TestCaseMixin(object):
     * Each test method will be run in a unique Eliot action context which
       identifies the test and collects all Eliot log messages emitted by that
       test (including setUp and tearDown messages).
+    * trial-compatible mktemp method
+    * unittest2-compatible assertRaises helper
     """
     @eliot_logged_test
     def run(self, result):
         return super(TestCase, self).run(result)
 
+    def setUp(self):
+        # Restore the original temporary directory.  Node ``init_tempdir``
+        # mangles it and many tests manage to get that method called.
+        self.addCleanup(
+            partial(setattr, tempfile, "tempdir", tempfile.tempdir),
+        )
+        return super(_TestCaseMixin, self).setUp()
+
+    class _DummyCase(_case.TestCase):
+        def dummy(self):
+            pass
+    _dummyCase = _DummyCase("dummy")
+
+    def mktemp(self):
+        return mktemp()
+
+    def assertRaises(self, *a, **kw):
+        return self._dummyCase.assertRaises(*a, **kw)
+
 
 class SyncTestCase(_TestCaseMixin, TestCase):
     """