add tests for BitField...

just a warning, I've completely forgotten how this metaclass stuff
works...  But it still behaves as it should.

ui/medashare/metadata/BitField.py

@@ -1,3 +1,5 @@
+import unittest
+
 class BitFieldMetaClass:
 	def __init__(self, name, bases, dct):
 		for base in bases:
@@ -53,10 +55,28 @@ class BitFieldInstance(object):
 BitField = BitFieldMetaClass("BitField", (), {})
 __all__ = [ 'BitField' ]
 
-def bftest():
-	class foo(BitField):
-		bar = 3
-		foo = 4
-		bleh = 16
+class _BFTest(unittest.TestCase):
+	def test_bftest(self):
+		class foo(BitField):
+			bar = 3
+			foo = 4
+			bleh = 16
+
+		i = foo(16)
+
+		self.assertEqual(int(i), 16)
+		self.assertFalse(i.bar)
+		self.assertTrue(i.foo)
+		self.assertFalse(i.bleh)
+
+		with self.assertRaises(AttributeError):
+			i.asldfkj
+
+		i.bar = True
+
+		self.assertTrue(i.bar)
+
+		self.assertEqual(int(i), 2**4 | 2**3)
 
-	return foo(16)
+		self.assertEqual(repr(i), "BitFieldInstance('foo', {'bar': 3, 'foo': 4, 'bleh': 16}, 24)")
+		self.assertEqual(str(i), '<bar,foo>')

ui/medashare/tests.py

@@ -10,3 +10,4 @@ from .magic import _TestMagic
 from .metadata.crw import _TestCRW
 from .metadata.crw import _TestFileMock
 from .metadata.crw import _TestSparseCover
+from .metadata.BitField import _BFTest