[tor-commits] [stem/master] Test when tail() is unable to read the file

[atagar at torproject.org]

commit e5046f73a1bfe49cfa7a0b312d11c558c7e47818
Author: Damian Johnson <atagar at torproject.org>
Date:   Wed Apr 1 09:51:31 2015 -0700

    Test when tail() is unable to read the file
---
 stem/util/system.py            |    2 ++
 test/unit/descriptor/reader.py |    5 ++---
 test/unit/util/system.py       |    9 +++++++++
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/stem/util/system.py b/stem/util/system.py
index fd62b9d..56f3da5 100644
--- a/stem/util/system.py
+++ b/stem/util/system.py
@@ -756,6 +756,8 @@ def tail(target, lines = None):
   :param int lines: number of lines to read
 
   :returns: **list** of lines the file ends with
+
+  :raises: **IOError** if unable to read the file
   """
 
   if isinstance(target, str):
diff --git a/test/unit/descriptor/reader.py b/test/unit/descriptor/reader.py
index debb88a..eaea7ea 100644
--- a/test/unit/descriptor/reader.py
+++ b/test/unit/descriptor/reader.py
@@ -635,8 +635,7 @@ class TestDescriptorReader(unittest.TestCase):
     it is located.
     """
 
-    test_listing_file = open(self.test_listing_path, 'w')
-    test_listing_file.write(contents)
-    test_listing_file.close()
+    with open(self.test_listing_path, 'w') as test_listing_file:
+      test_listing_file.write(contents)
 
     return self.test_listing_path
diff --git a/test/unit/util/system.py b/test/unit/util/system.py
index 98cfb8d..e3de4d8 100644
--- a/test/unit/util/system.py
+++ b/test/unit/util/system.py
@@ -9,6 +9,7 @@ import functools
 import ntpath
 import os
 import posixpath
+import tempfile
 import unittest
 
 from stem import str_type
@@ -391,6 +392,14 @@ class TestSystem(unittest.TestCase):
     self.assertEqual(14, len(system.tail(path)))
     self.assertEqual(14, len(system.tail(path, 200)))
 
+    self.assertRaises(IOError, system.tail, '/path/doesnt/exist')
+
+    fd, temp_path = tempfile.mkstemp()
+    os.chmod(temp_path, 0o077)  # remove read permissions
+    self.assertRaises(IOError, system.tail, temp_path)
+    os.close(fd)
+    os.remove(temp_path)
+
   @patch('stem.util.system.call')
   @patch('stem.util.system.is_available', Mock(return_value = True))
   def test_bsd_jail_id(self, call_mock):