make bad file descriptor tests more robust

1 files changed, 17 insertions, 13 deletions

diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py
index 5c94d7d..cd310ea 100644
--- a/Lib/test/test_os.py
+++ b/Lib/test/test_os.py
@@ -540,55 +540,59 @@ class TestInvalidFD(unittest.TestCase):
     #We omit close because it doesn'r raise an exception on some platforms
     def get_single(f):
         def helper(self):
-            if  getattr(os, f, None):
-                self.assertRaises(OSError, getattr(os, f), 10)
+            if  hasattr(os, f):
+                self.check(getattr(os, f))
         return helper
     for f in singles:
         locals()["test_"+f] = get_single(f)
 
+    def check(self, f, *args):
+        self.assertRaises(OSError, f, test_support.make_bad_fd(), *args)
+
     def test_isatty(self):
         if hasattr(os, "isatty"):
-            self.assertEqual(os.isatty(10), False)
+            self.assertEqual(os.isatty(test_support.make_bad_fd()), False)
 
     def test_closerange(self):
         if hasattr(os, "closerange"):
-            self.assertEqual(os.closerange(10, 20), None)
+            fd = test_support.make_bad_fd()
+            self.assertEqual(os.closerange(fd, fd + 10), None)
 
     def test_dup2(self):
         if hasattr(os, "dup2"):
-            self.assertRaises(OSError, os.dup2, 10, 20)
+            self.check(os.dup2, 20)
 
     def test_fchmod(self):
         if hasattr(os, "fchmod"):
-            self.assertRaises(OSError, os.fchmod, 10, 0)
+            self.check(os.fchmod, 0)
 
     def test_fchown(self):
         if hasattr(os, "fchown"):
-            self.assertRaises(OSError, os.fchown, 10, -1, -1)
+            self.check(os.fchown, -1, -1)
 
     def test_fpathconf(self):
         if hasattr(os, "fpathconf"):
-            self.assertRaises(OSError, os.fpathconf, 10, "PC_NAME_MAX")
+            self.check(os.fpathconf, "PC_NAME_MAX")
 
     def test_ftruncate(self):
         if hasattr(os, "ftruncate"):
-            self.assertRaises(OSError, os.ftruncate, 10, 0)
+            self.check(os.ftruncate, 0)
 
     def test_lseek(self):
         if hasattr(os, "lseek"):
-            self.assertRaises(OSError, os.lseek, 10, 0, 0)
+            self.check(os.lseek, 0, 0)
 
     def test_read(self):
         if hasattr(os, "read"):
-            self.assertRaises(OSError, os.read, 10, 1)
+            self.check(os.read, 1)
 
     def test_tcsetpgrpt(self):
         if hasattr(os, "tcsetpgrp"):
-            self.assertRaises(OSError, os.tcsetpgrp, 10, 0)
+            self.check(os.tcsetpgrp, 0)
 
     def test_write(self):
         if hasattr(os, "write"):
-            self.assertRaises(OSError, os.write, 10, " ")
+            self.check(os.write, " ")
 
 if sys.platform != 'win32':
     class Win32ErrorTests(unittest.TestCase):