Fix test_non_numeric_pid (and put it in a better place too)

src/allmydata/scripts/tahoe_run.py

@@ -182,7 +182,7 @@ class DaemonizeTahoeNodePlugin(object):
         return DaemonizeTheRealService(self.nodetype, self.basedir, so)
 
 
-def run(config):
+def run(config, runApp=twistd.runApp):
     """
     Runs a Tahoe-LAFS node in the foreground.
 
@@ -202,10 +202,7 @@ def run(config):
     if not nodetype:
         print("%s is not a recognizable node directory" % quoted_basedir, file=err)
         return 1
-    # Now prepare to turn into a twistd process. This os.chdir is the point
-    # of no return.
-    os.chdir(basedir)
-    twistd_args = ["--nodaemon"]
+    twistd_args = ["--nodaemon", "--rundir", basedir]
     twistd_args.extend(config.twistd_args)
     twistd_args.append("DaemonizeTahoeNode") # point at our DaemonizeTahoeNodePlugin
 
@@ -229,5 +226,5 @@ def run(config):
 
     # We always pass --nodaemon so twistd.runApp does not daemonize.
     print("running node in %s" % (quoted_basedir,), file=out)
-    twistd.runApp(twistd_config)
+    runApp(twistd_config)
     return 0

src/allmydata/test/cli/test_cli.py

@@ -2,10 +2,8 @@ import os.path
 from six.moves import cStringIO as StringIO
 import urllib
 import re
-from mock import patch
 
 from twisted.trial import unittest
-from twisted.python.filepath import FilePath
 from twisted.internet.testing import (
     MemoryReactor,
 )
@@ -1308,30 +1306,3 @@ class Options(ReallyEqualMixin, unittest.TestCase):
                               ["--node-directory=there", "run", some_twistd_option])
         self.failUnlessRaises(usage.UsageError, self.parse,
                               ["run", "--basedir=here", some_twistd_option])
-
-
-class Run(unittest.TestCase):
-
-    @patch('allmydata.scripts.tahoe_run.os.chdir')
-    @patch('allmydata.scripts.tahoe_run.twistd')
-    def test_non_numeric_pid(self, mock_twistd, chdir):
-        """
-        If the pidfile exists but does not contain a numeric value, a complaint to
-        this effect is written to stderr.
-        """
-        basedir = FilePath(self.mktemp().decode("ascii"))
-        basedir.makedirs()
-        basedir.child(u"twistd.pid").setContent(b"foo")
-        basedir.child(u"tahoe-client.tac").setContent(b"")
-
-        config = tahoe_run.RunOptions()
-        config.stdout = StringIO()
-        config.stderr = StringIO()
-        config['basedir'] = basedir.path
-        config.twistd_args = []
-
-        result_code = tahoe_run.run(config)
-        self.assertIn("invalid PID file", config.stderr.getvalue())
-        self.assertTrue(len(mock_twistd.mock_calls), 1)
-        self.assertEqual(mock_twistd.mock_calls[0][0], 'runApp')
-        self.assertEqual(0, result_code)

src/allmydata/test/cli/test_run.py

@@ -9,6 +9,7 @@ from six.moves import (
 from testtools.matchers import (
     Contains,
     Equals,
+    HasLength,
 )
 
 from twisted.python.filepath import (
@@ -23,6 +24,8 @@ from twisted.internet.test.modulehelpers import (
 
 from ...scripts.tahoe_run import (
     DaemonizeTheRealService,
+    RunOptions,
+    run,
 )
 
 from ...scripts.runner import (
@@ -125,3 +128,39 @@ class DaemonizeTheRealServiceTests(SyncTestCase):
             """,
             "Privacy requested",
         )
+
+
+class RunTests(SyncTestCase):
+    """
+    Tests for ``run``.
+    """
+    def test_non_numeric_pid(self):
+        """
+        If the pidfile exists but does not contain a numeric value, a complaint to
+        this effect is written to stderr.
+        """
+        basedir = FilePath(self.mktemp().decode("ascii"))
+        basedir.makedirs()
+        basedir.child(u"twistd.pid").setContent(b"foo")
+        basedir.child(u"tahoe-client.tac").setContent(b"")
+
+        config = RunOptions()
+        config.stdout = StringIO()
+        config.stderr = StringIO()
+        config['basedir'] = basedir.path
+        config.twistd_args = []
+
+        runs = []
+        result_code = run(config, runApp=runs.append)
+        self.assertThat(
+            config.stderr.getvalue(),
+            Contains("found invalid PID file in"),
+        )
+        self.assertThat(
+            runs,
+            HasLength(1),
+        )
+        self.assertThat(
+            result_code,
+            Equals(0),
+        )