Create global instance of command-line options

This eases testing of option values inside the code.  This instance
is implemented as the read-only copy of the obtained 'options' object,
so callers won't be able to modify its contents.

Signed-off-by: Eygene Ryabinkin <rea@codelabs.ru>

test/tests/test_00_globals.py

@@ -0,0 +1,51 @@
+#!/usr/bin/env python
+# Copyright 2013 Eygene A. Ryabinkin
+
+from offlineimap import globals
+import unittest
+
+class Opt:
+	def __init__(self):
+		self.one = "baz"
+		self.two = 42
+		self.three = True
+
+
+class TestOfflineimapGlobals(unittest.TestCase):
+
+	@classmethod
+	def setUpClass(klass):
+		klass.o = Opt()
+		globals.set_options (klass.o)
+
+	def test_initial_state(self):
+		for k in self.o.__dict__.keys():
+			self.assertTrue(getattr(self.o, k) ==
+			  getattr(globals.options, k))
+
+	def test_object_changes(self):
+		self.o.one = "one"
+		self.o.two = 119
+		self.o.three = False
+		return self.test_initial_state()
+
+	def test_modification(self):
+		with self.assertRaises(AttributeError):
+			globals.options.two = True
+
+	def test_deletion(self):
+		with self.assertRaises(RuntimeError):
+			del globals.options.three
+
+	def test_nonexistent_key(self):
+		with self.assertRaises(AttributeError):
+			a = globals.options.nosuchoption
+
+	def test_double_init(self):
+		with self.assertRaises(ValueError):
+			globals.set_options (True)
+
+
+if __name__ == "__main__":
+	suite = unittest.TestLoader().loadTestsFromTestCase(TestOfflineimapGlobals)
+	unittest.TextTestRunner(verbosity=2).run(suite)