Issue #23842: Added tests for os.major(), os.minor() and os.makedev().

Lib/test/test_posix.py

@@ -443,6 +443,36 @@ class PosixTester(unittest.TestCase):
         else:
             self.assertTrue(stat.S_ISFIFO(posix.stat(support.TESTFN).st_mode))
 
+    @unittest.skipUnless(hasattr(posix, 'stat'), 'test needs posix.stat()')
+    @unittest.skipUnless(hasattr(posix, 'makedev'), 'test needs posix.makedev()')
+    def test_makedev(self):
+        st = posix.stat(support.TESTFN)
+        dev = st.st_dev
+        self.assertIsInstance(dev, int)
+        self.assertGreaterEqual(dev, 0)
+
+        major = posix.major(dev)
+        self.assertIsInstance(major, int)
+        self.assertGreaterEqual(major, 0)
+        self.assertEqual(posix.major(dev), major)
+        self.assertRaises(TypeError, posix.major, float(dev))
+        self.assertRaises(TypeError, posix.major)
+        self.assertRaises((ValueError, OverflowError), posix.major, -1)
+
+        minor = posix.minor(dev)
+        self.assertIsInstance(minor, int)
+        self.assertGreaterEqual(minor, 0)
+        self.assertEqual(posix.minor(dev), minor)
+        self.assertRaises(TypeError, posix.minor, float(dev))
+        self.assertRaises(TypeError, posix.minor)
+        self.assertRaises((ValueError, OverflowError), posix.minor, -1)
+
+        self.assertEqual(posix.makedev(major, minor), dev)
+        self.assertRaises(TypeError, posix.makedev, float(major), minor)
+        self.assertRaises(TypeError, posix.makedev, major, float(minor))
+        self.assertRaises(TypeError, posix.makedev, major)
+        self.assertRaises(TypeError, posix.makedev)
+
     def _test_all_chown_common(self, chown_func, first_param, stat_func):
         """Common code for chown, fchown and lchown tests."""
         def check_stat(uid, gid):