add some docstrings, fix comments

src/allmydata/test/test_client.py

@@ -214,6 +214,9 @@ class Basic(testutil.ReallyEqualMixin, testutil.NonASCIIPathMixin, unittest.Test
         self.failUnlessRaises(ValueError, client.create_client, basedir)
 
     def test_web_apiauthtoken(self):
+        """
+        Client loads the proper API auth token from disk
+        """
         basedir = u"client.Basic.test_web_apiauthtoken"
         create_node_dir(basedir, "testing")
 
@@ -243,6 +246,9 @@ class Basic(testutil.ReallyEqualMixin, testutil.NonASCIIPathMixin, unittest.Test
     # TODO: also test config options for SFTP.
 
     def test_ftp_create(self):
+        """
+        configuration for sftpd results in it being started
+        """
         basedir = u"client.Basic.test_ftp_create"
         create_node_dir(basedir, "testing")
         with open(os.path.join(basedir, "tahoe.cfg"), "w") as f:

src/allmydata/test/test_introducer.py

@@ -42,6 +42,9 @@ class Node(testutil.SignalMixin, testutil.ReallyEqualMixin, unittest.TestCase):
         IntroducerNode  # pyflakes
 
     def test_create(self):
+        """
+        A brand new introducer creates its config dir
+        """
         basedir = "introducer.IntroducerNode.test_create"
         create_introducer(basedir)
         self.assertTrue(os.path.exists(basedir))

src/allmydata/test/test_node.py

@@ -138,6 +138,9 @@ class TestCase(testutil.SignalMixin, unittest.TestCase):
         self.failUnless(config.nickname == nickname)
 
     def test_config_required(self):
+        """
+        Asking for missing (but required) configuration is an error
+        """
         basedir = u"test_node/test_config_required"
         config = read_config(basedir, "portnum")
 
@@ -145,6 +148,9 @@ class TestCase(testutil.SignalMixin, unittest.TestCase):
             config.get_config_from_file("it_does_not_exist", required=True)
 
     def test_private_config_unreadable(self):
+        """
+        Asking for inaccessible private config is an error
+        """
         if "win32" in sys.platform.lower() or "cygwin" in sys.platform.lower():
             # We don't know how to test that unprivileged users can't read this
             # thing.  (Also we don't know exactly how to set the permissions so