test positional args in HasTraits

IPython/utils/tests/test_traitlets.py

@@ -1,920 +1,932 b''
 # encoding: utf-8
 """
 Tests for IPython.utils.traitlets.
 
 Authors:
 
 * Brian Granger
 * Enthought, Inc.  Some of the code in this file comes from enthought.traits
   and is licensed under the BSD license.  Also, many of the ideas also come
   from enthought.traits even though our implementation is very different.
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import re
 import sys
 from unittest import TestCase
 
 import nose.tools as nt
 from nose import SkipTest
 
 from IPython.utils.traitlets import (
     HasTraits, MetaHasTraits, TraitType, Any, CBytes, Dict,
     Int, Long, Integer, Float, Complex, Bytes, Unicode, TraitError,
     Undefined, Type, This, Instance, TCPAddress, List, Tuple,
     ObjectName, DottedObjectName, CRegExp
 )
 from IPython.utils import py3compat
 from IPython.testing.decorators import skipif
 
 #-----------------------------------------------------------------------------
 # Helper classes for testing
 #-----------------------------------------------------------------------------
 
 
 class HasTraitsStub(HasTraits):
 
     def _notify_trait(self, name, old, new):
         self._notify_name = name
         self._notify_old = old
         self._notify_new = new
 
 
 #-----------------------------------------------------------------------------
 # Test classes
 #-----------------------------------------------------------------------------
 
 
 class TestTraitType(TestCase):
 
     def test_get_undefined(self):
         class A(HasTraits):
             a = TraitType
         a = A()
         self.assertEqual(a.a, Undefined)
 
     def test_set(self):
         class A(HasTraitsStub):
             a = TraitType
 
         a = A()
         a.a = 10
         self.assertEqual(a.a, 10)
         self.assertEqual(a._notify_name, 'a')
         self.assertEqual(a._notify_old, Undefined)
         self.assertEqual(a._notify_new, 10)
 
     def test_validate(self):
         class MyTT(TraitType):
             def validate(self, inst, value):
                 return -1
         class A(HasTraitsStub):
             tt = MyTT
 
         a = A()
         a.tt = 10
         self.assertEqual(a.tt, -1)
 
     def test_default_validate(self):
         class MyIntTT(TraitType):
             def validate(self, obj, value):
                 if isinstance(value, int):
                     return value
                 self.error(obj, value)
         class A(HasTraits):
             tt = MyIntTT(10)
         a = A()
         self.assertEqual(a.tt, 10)
 
         # Defaults are validated when the HasTraits is instantiated
         class B(HasTraits):
             tt = MyIntTT('bad default')
         self.assertRaises(TraitError, B)
 
     def test_is_valid_for(self):
         class MyTT(TraitType):
             def is_valid_for(self, value):
                 return True
         class A(HasTraits):
             tt = MyTT
 
         a = A()
         a.tt = 10
         self.assertEqual(a.tt, 10)
 
     def test_value_for(self):
         class MyTT(TraitType):
             def value_for(self, value):
                 return 20
         class A(HasTraits):
             tt = MyTT
 
         a = A()
         a.tt = 10
         self.assertEqual(a.tt, 20)
 
     def test_info(self):
         class A(HasTraits):
             tt = TraitType
         a = A()
         self.assertEqual(A.tt.info(), 'any value')
 
     def test_error(self):
         class A(HasTraits):
             tt = TraitType
         a = A()
         self.assertRaises(TraitError, A.tt.error, a, 10)
 
     def test_dynamic_initializer(self):
         class A(HasTraits):
             x = Int(10)
             def _x_default(self):
                 return 11
         class B(A):
             x = Int(20)
         class C(A):
             def _x_default(self):
                 return 21
 
         a = A()
         self.assertEqual(a._trait_values, {})
         self.assertEqual(a._trait_dyn_inits.keys(), ['x'])
         self.assertEqual(a.x, 11)
         self.assertEqual(a._trait_values, {'x': 11})
         b = B()
         self.assertEqual(b._trait_values, {'x': 20})
         self.assertEqual(a._trait_dyn_inits.keys(), ['x'])
         self.assertEqual(b.x, 20)
         c = C()
         self.assertEqual(c._trait_values, {})
         self.assertEqual(a._trait_dyn_inits.keys(), ['x'])
         self.assertEqual(c.x, 21)
         self.assertEqual(c._trait_values, {'x': 21})
         # Ensure that the base class remains unmolested when the _default
         # initializer gets overridden in a subclass.
         a = A()
         c = C()
         self.assertEqual(a._trait_values, {})
         self.assertEqual(a._trait_dyn_inits.keys(), ['x'])
         self.assertEqual(a.x, 11)
         self.assertEqual(a._trait_values, {'x': 11})
 
 
 
 class TestHasTraitsMeta(TestCase):
 
     def test_metaclass(self):
         self.assertEqual(type(HasTraits), MetaHasTraits)
 
         class A(HasTraits):
             a = Int
 
         a = A()
         self.assertEqual(type(a.__class__), MetaHasTraits)
         self.assertEqual(a.a,0)
         a.a = 10
         self.assertEqual(a.a,10)
 
         class B(HasTraits):
             b = Int()
 
         b = B()
         self.assertEqual(b.b,0)
         b.b = 10
         self.assertEqual(b.b,10)
 
         class C(HasTraits):
             c = Int(30)
 
         c = C()
         self.assertEqual(c.c,30)
         c.c = 10
         self.assertEqual(c.c,10)
 
     def test_this_class(self):
         class A(HasTraits):
             t = This()
             tt = This()
         class B(A):
             tt = This()
             ttt = This()
         self.assertEqual(A.t.this_class, A)
         self.assertEqual(B.t.this_class, A)
         self.assertEqual(B.tt.this_class, B)
         self.assertEqual(B.ttt.this_class, B)
 
 class TestHasTraitsNotify(TestCase):
 
     def setUp(self):
         self._notify1 = []
         self._notify2 = []
 
     def notify1(self, name, old, new):
         self._notify1.append((name, old, new))
 
     def notify2(self, name, old, new):
         self._notify2.append((name, old, new))
 
     def test_notify_all(self):
 
         class A(HasTraits):
             a = Int
             b = Float
 
         a = A()
         a.on_trait_change(self.notify1)
         a.a = 0
         self.assertEqual(len(self._notify1),0)
         a.b = 0.0
         self.assertEqual(len(self._notify1),0)
         a.a = 10
         self.assertTrue(('a',0,10) in self._notify1)
         a.b = 10.0
         self.assertTrue(('b',0.0,10.0) in self._notify1)
         self.assertRaises(TraitError,setattr,a,'a','bad string')
         self.assertRaises(TraitError,setattr,a,'b','bad string')
         self._notify1 = []
         a.on_trait_change(self.notify1,remove=True)
         a.a = 20
         a.b = 20.0
         self.assertEqual(len(self._notify1),0)
 
     def test_notify_one(self):
 
         class A(HasTraits):
             a = Int
             b = Float
 
         a = A()
         a.on_trait_change(self.notify1, 'a')
         a.a = 0
         self.assertEqual(len(self._notify1),0)
         a.a = 10
         self.assertTrue(('a',0,10) in self._notify1)
         self.assertRaises(TraitError,setattr,a,'a','bad string')
 
     def test_subclass(self):
 
         class A(HasTraits):
             a = Int
 
         class B(A):
             b = Float
 
         b = B()
         self.assertEqual(b.a,0)
         self.assertEqual(b.b,0.0)
         b.a = 100
         b.b = 100.0
         self.assertEqual(b.a,100)
         self.assertEqual(b.b,100.0)
 
     def test_notify_subclass(self):
 
         class A(HasTraits):
             a = Int
 
         class B(A):
             b = Float
 
         b = B()
         b.on_trait_change(self.notify1, 'a')
         b.on_trait_change(self.notify2, 'b')
         b.a = 0
         b.b = 0.0
         self.assertEqual(len(self._notify1),0)
         self.assertEqual(len(self._notify2),0)
         b.a = 10
         b.b = 10.0
         self.assertTrue(('a',0,10) in self._notify1)
         self.assertTrue(('b',0.0,10.0) in self._notify2)
 
     def test_static_notify(self):
 
         class A(HasTraits):
             a = Int
             _notify1 = []
             def _a_changed(self, name, old, new):
                 self._notify1.append((name, old, new))
 
         a = A()
         a.a = 0
         # This is broken!!!
         self.assertEqual(len(a._notify1),0)
         a.a = 10
         self.assertTrue(('a',0,10) in a._notify1)
 
         class B(A):
             b = Float
             _notify2 = []
             def _b_changed(self, name, old, new):
                 self._notify2.append((name, old, new))
 
         b = B()
         b.a = 10
         b.b = 10.0
         self.assertTrue(('a',0,10) in b._notify1)
         self.assertTrue(('b',0.0,10.0) in b._notify2)
 
     def test_notify_args(self):
 
         def callback0():
             self.cb = ()
         def callback1(name):
             self.cb = (name,)
         def callback2(name, new):
             self.cb = (name, new)
         def callback3(name, old, new):
             self.cb = (name, old, new)
 
         class A(HasTraits):
             a = Int
 
         a = A()
         a.on_trait_change(callback0, 'a')
         a.a = 10
         self.assertEqual(self.cb,())
         a.on_trait_change(callback0, 'a', remove=True)
 
         a.on_trait_change(callback1, 'a')
         a.a = 100
         self.assertEqual(self.cb,('a',))
         a.on_trait_change(callback1, 'a', remove=True)
 
         a.on_trait_change(callback2, 'a')
         a.a = 1000
         self.assertEqual(self.cb,('a',1000))
         a.on_trait_change(callback2, 'a', remove=True)
 
         a.on_trait_change(callback3, 'a')
         a.a = 10000
         self.assertEqual(self.cb,('a',1000,10000))
         a.on_trait_change(callback3, 'a', remove=True)
 
         self.assertEqual(len(a._trait_notifiers['a']),0)
 
 
 class TestHasTraits(TestCase):
 
     def test_trait_names(self):
         class A(HasTraits):
             i = Int
             f = Float
         a = A()
         self.assertEqual(sorted(a.trait_names()),['f','i'])
         self.assertEqual(sorted(A.class_trait_names()),['f','i'])
 
     def test_trait_metadata(self):
         class A(HasTraits):
             i = Int(config_key='MY_VALUE')
         a = A()
         self.assertEqual(a.trait_metadata('i','config_key'), 'MY_VALUE')
 
     def test_traits(self):
         class A(HasTraits):
             i = Int
             f = Float
         a = A()
         self.assertEqual(a.traits(), dict(i=A.i, f=A.f))
         self.assertEqual(A.class_traits(), dict(i=A.i, f=A.f))
 
     def test_traits_metadata(self):
         class A(HasTraits):
             i = Int(config_key='VALUE1', other_thing='VALUE2')
             f = Float(config_key='VALUE3', other_thing='VALUE2')
             j = Int(0)
         a = A()
         self.assertEqual(a.traits(), dict(i=A.i, f=A.f, j=A.j))
         traits = a.traits(config_key='VALUE1', other_thing='VALUE2')
         self.assertEqual(traits, dict(i=A.i))
 
         # This passes, but it shouldn't because I am replicating a bug in
         # traits.
         traits = a.traits(config_key=lambda v: True)
         self.assertEqual(traits, dict(i=A.i, f=A.f, j=A.j))
 
     def test_init(self):
         class A(HasTraits):
             i = Int()
             x = Float()
         a = A(i=1, x=10.0)
         self.assertEqual(a.i, 1)
         self.assertEqual(a.x, 10.0)
 
+    def test_positional_args(self):
+        class A(HasTraits):
+            i = Int(0)
+            def __init__(self, i):
+                super(A, self).__init__()
+                self.i = i
+        
+        a = A(5)
+        self.assertEqual(a.i, 5)
+        # should raise TypeError if no positional arg given
+        self.assertRaises(TypeError, A)
+
 #-----------------------------------------------------------------------------
 # Tests for specific trait types
 #-----------------------------------------------------------------------------
 
 
 class TestType(TestCase):
 
     def test_default(self):
 
         class B(object): pass
         class A(HasTraits):
             klass = Type
 
         a = A()
         self.assertEqual(a.klass, None)
 
         a.klass = B
         self.assertEqual(a.klass, B)
         self.assertRaises(TraitError, setattr, a, 'klass', 10)
 
     def test_value(self):
 
         class B(object): pass
         class C(object): pass
         class A(HasTraits):
             klass = Type(B)
 
         a = A()
         self.assertEqual(a.klass, B)
         self.assertRaises(TraitError, setattr, a, 'klass', C)
         self.assertRaises(TraitError, setattr, a, 'klass', object)
         a.klass = B
 
     def test_allow_none(self):
 
         class B(object): pass
         class C(B): pass
         class A(HasTraits):
             klass = Type(B, allow_none=False)
 
         a = A()
         self.assertEqual(a.klass, B)
         self.assertRaises(TraitError, setattr, a, 'klass', None)
         a.klass = C
         self.assertEqual(a.klass, C)
 
     def test_validate_klass(self):
 
         class A(HasTraits):
             klass = Type('no strings allowed')
 
         self.assertRaises(ImportError, A)
 
         class A(HasTraits):
             klass = Type('rub.adub.Duck')
 
         self.assertRaises(ImportError, A)
 
     def test_validate_default(self):
 
         class B(object): pass
         class A(HasTraits):
             klass = Type('bad default', B)
 
         self.assertRaises(ImportError, A)
 
         class C(HasTraits):
             klass = Type(None, B, allow_none=False)
 
         self.assertRaises(TraitError, C)
 
     def test_str_klass(self):
 
         class A(HasTraits):
             klass = Type('IPython.utils.ipstruct.Struct')
 
         from IPython.utils.ipstruct import Struct
         a = A()
         a.klass = Struct
         self.assertEqual(a.klass, Struct)
 
         self.assertRaises(TraitError, setattr, a, 'klass', 10)
 
 class TestInstance(TestCase):
 
     def test_basic(self):
         class Foo(object): pass
         class Bar(Foo): pass
         class Bah(object): pass
 
         class A(HasTraits):
             inst = Instance(Foo)
 
         a = A()
         self.assertTrue(a.inst is None)
         a.inst = Foo()
         self.assertTrue(isinstance(a.inst, Foo))
         a.inst = Bar()
         self.assertTrue(isinstance(a.inst, Foo))
         self.assertRaises(TraitError, setattr, a, 'inst', Foo)
         self.assertRaises(TraitError, setattr, a, 'inst', Bar)
         self.assertRaises(TraitError, setattr, a, 'inst', Bah())
 
     def test_unique_default_value(self):
         class Foo(object): pass
         class A(HasTraits):
             inst = Instance(Foo,(),{})
 
         a = A()
         b = A()
         self.assertTrue(a.inst is not b.inst)
 
     def test_args_kw(self):
         class Foo(object):
             def __init__(self, c): self.c = c
         class Bar(object): pass
         class Bah(object):
             def __init__(self, c, d):
                 self.c = c; self.d = d
 
         class A(HasTraits):
             inst = Instance(Foo, (10,))
         a = A()
         self.assertEqual(a.inst.c, 10)
 
         class B(HasTraits):
             inst = Instance(Bah, args=(10,), kw=dict(d=20))
         b = B()
         self.assertEqual(b.inst.c, 10)
         self.assertEqual(b.inst.d, 20)
 
         class C(HasTraits):
             inst = Instance(Foo)
         c = C()
         self.assertTrue(c.inst is None)
 
     def test_bad_default(self):
         class Foo(object): pass
 
         class A(HasTraits):
             inst = Instance(Foo, allow_none=False)
 
         self.assertRaises(TraitError, A)
 
     def test_instance(self):
         class Foo(object): pass
 
         def inner():
             class A(HasTraits):
                 inst = Instance(Foo())
 
         self.assertRaises(TraitError, inner)
 
 
 class TestThis(TestCase):
 
     def test_this_class(self):
         class Foo(HasTraits):
             this = This
 
         f = Foo()
         self.assertEqual(f.this, None)
         g = Foo()
         f.this = g
         self.assertEqual(f.this, g)
         self.assertRaises(TraitError, setattr, f, 'this', 10)
 
     def test_this_inst(self):
         class Foo(HasTraits):
             this = This()
 
         f = Foo()
         f.this = Foo()
         self.assertTrue(isinstance(f.this, Foo))
 
     def test_subclass(self):
         class Foo(HasTraits):
             t = This()
         class Bar(Foo):
             pass
         f = Foo()
         b = Bar()
         f.t = b
         b.t = f
         self.assertEqual(f.t, b)
         self.assertEqual(b.t, f)
 
     def test_subclass_override(self):
         class Foo(HasTraits):
             t = This()
         class Bar(Foo):
             t = This()
         f = Foo()
         b = Bar()
         f.t = b
         self.assertEqual(f.t, b)
         self.assertRaises(TraitError, setattr, b, 't', f)
 
 class TraitTestBase(TestCase):
     """A best testing class for basic trait types."""
 
     def assign(self, value):
         self.obj.value = value
 
     def coerce(self, value):
         return value
 
     def test_good_values(self):
         if hasattr(self, '_good_values'):
             for value in self._good_values:
                 self.assign(value)
                 self.assertEqual(self.obj.value, self.coerce(value))
 
     def test_bad_values(self):
         if hasattr(self, '_bad_values'):
             for value in self._bad_values:
                 try:
                     self.assertRaises(TraitError, self.assign, value)
                 except AssertionError:
                     assert False, value
 
     def test_default_value(self):
         if hasattr(self, '_default_value'):
             self.assertEqual(self._default_value, self.obj.value)
 
     def tearDown(self):
         # restore default value after tests, if set
         if hasattr(self, '_default_value'):
             self.obj.value = self._default_value
 
 
 class AnyTrait(HasTraits):
 
     value = Any
 
 class AnyTraitTest(TraitTestBase):
 
     obj = AnyTrait()
 
     _default_value = None
     _good_values   = [10.0, 'ten', u'ten', [10], {'ten': 10},(10,), None, 1j]
     _bad_values    = []
 
 
 class IntTrait(HasTraits):
 
     value = Int(99)
 
 class TestInt(TraitTestBase):
 
     obj = IntTrait()
     _default_value = 99
     _good_values   = [10, -10]
     _bad_values    = ['ten', u'ten', [10], {'ten': 10},(10,), None, 1j,
                       10.1, -10.1, '10L', '-10L', '10.1', '-10.1', u'10L',
                       u'-10L', u'10.1', u'-10.1',  '10', '-10', u'10', u'-10']
     if not py3compat.PY3:
         _bad_values.extend([10L, -10L, 10*sys.maxint, -10*sys.maxint])
 
 
 class LongTrait(HasTraits):
 
     value = Long(99L)
 
 class TestLong(TraitTestBase):
 
     obj = LongTrait()
 
     _default_value = 99L
     _good_values   = [10, -10, 10L, -10L]
     _bad_values    = ['ten', u'ten', [10], [10l], {'ten': 10},(10,),(10L,),
                       None, 1j, 10.1, -10.1, '10', '-10', '10L', '-10L', '10.1',
                       '-10.1', u'10', u'-10', u'10L', u'-10L', u'10.1',
                       u'-10.1']
     if not py3compat.PY3:
         # maxint undefined on py3, because int == long
         _good_values.extend([10*sys.maxint, -10*sys.maxint])
 
     @skipif(py3compat.PY3, "not relevant on py3")
     def test_cast_small(self):
         """Long casts ints to long"""
         self.obj.value = 10
         self.assertEqual(type(self.obj.value), long)
 
 
 class IntegerTrait(HasTraits):
     value = Integer(1)
 
 class TestInteger(TestLong):
     obj = IntegerTrait()
     _default_value = 1
 
     def coerce(self, n):
         return int(n)
 
     @skipif(py3compat.PY3, "not relevant on py3")
     def test_cast_small(self):
         """Integer casts small longs to int"""
         if py3compat.PY3:
             raise SkipTest("not relevant on py3")
 
         self.obj.value = 100L
         self.assertEqual(type(self.obj.value), int)
 
 
 class FloatTrait(HasTraits):
 
     value = Float(99.0)
 
 class TestFloat(TraitTestBase):
 
     obj = FloatTrait()
 
     _default_value = 99.0
     _good_values   = [10, -10, 10.1, -10.1]
     _bad_values    = ['ten', u'ten', [10], {'ten': 10},(10,), None,
                       1j, '10', '-10', '10L', '-10L', '10.1', '-10.1', u'10',
                       u'-10', u'10L', u'-10L', u'10.1', u'-10.1']
     if not py3compat.PY3:
         _bad_values.extend([10L, -10L])
 
 
 class ComplexTrait(HasTraits):
 
     value = Complex(99.0-99.0j)
 
 class TestComplex(TraitTestBase):
 
     obj = ComplexTrait()
 
     _default_value = 99.0-99.0j
     _good_values   = [10, -10, 10.1, -10.1, 10j, 10+10j, 10-10j,
                       10.1j, 10.1+10.1j, 10.1-10.1j]
     _bad_values    = [u'10L', u'-10L', 'ten', [10], {'ten': 10},(10,), None]
     if not py3compat.PY3:
         _bad_values.extend([10L, -10L])
 
 
 class BytesTrait(HasTraits):
 
     value = Bytes(b'string')
 
 class TestBytes(TraitTestBase):
 
     obj = BytesTrait()
 
     _default_value = b'string'
     _good_values   = [b'10', b'-10', b'10L',
                       b'-10L', b'10.1', b'-10.1', b'string']
     _bad_values    = [10, -10, 10L, -10L, 10.1, -10.1, 1j, [10],
                       ['ten'],{'ten': 10},(10,), None,  u'string']
 
 
 class UnicodeTrait(HasTraits):
 
     value = Unicode(u'unicode')
 
 class TestUnicode(TraitTestBase):
 
     obj = UnicodeTrait()
 
     _default_value = u'unicode'
     _good_values   = ['10', '-10', '10L', '-10L', '10.1',
                       '-10.1', '', u'', 'string', u'string', u"€"]
     _bad_values    = [10, -10, 10L, -10L, 10.1, -10.1, 1j,
                       [10], ['ten'], [u'ten'], {'ten': 10},(10,), None]
 
 
 class ObjectNameTrait(HasTraits):
     value = ObjectName("abc")
 
 class TestObjectName(TraitTestBase):
     obj = ObjectNameTrait()
 
     _default_value = "abc"
     _good_values = ["a", "gh", "g9", "g_", "_G", u"a345_"]
     _bad_values = [1, "", u"€", "9g", "!", "#abc", "aj@", "a.b", "a()", "a[0]",
                                                             object(), object]
     if sys.version_info[0] < 3:
         _bad_values.append(u"þ")
     else:
         _good_values.append(u"þ")  # þ=1 is valid in Python 3 (PEP 3131).
 
 
 class DottedObjectNameTrait(HasTraits):
     value = DottedObjectName("a.b")
 
 class TestDottedObjectName(TraitTestBase):
     obj = DottedObjectNameTrait()
 
     _default_value = "a.b"
     _good_values = ["A", "y.t", "y765.__repr__", "os.path.join", u"os.path.join"]
     _bad_values = [1, u"abc.€", "_.@", ".", ".abc", "abc.", ".abc."]
     if sys.version_info[0] < 3:
         _bad_values.append(u"t.þ")
     else:
         _good_values.append(u"t.þ")
 
 
 class TCPAddressTrait(HasTraits):
 
     value = TCPAddress()
 
 class TestTCPAddress(TraitTestBase):
 
     obj = TCPAddressTrait()
 
     _default_value = ('127.0.0.1',0)
     _good_values = [('localhost',0),('192.168.0.1',1000),('www.google.com',80)]
     _bad_values = [(0,0),('localhost',10.0),('localhost',-1)]
 
 class ListTrait(HasTraits):
 
     value = List(Int)
 
 class TestList(TraitTestBase):
 
     obj = ListTrait()
 
     _default_value = []
     _good_values = [[], [1], range(10)]
     _bad_values = [10, [1,'a'], 'a', (1,2)]
 
 class LenListTrait(HasTraits):
 
     value = List(Int, [0], minlen=1, maxlen=2)
 
 class TestLenList(TraitTestBase):
 
     obj = LenListTrait()
 
     _default_value = [0]
     _good_values = [[1], range(2)]
     _bad_values = [10, [1,'a'], 'a', (1,2), [], range(3)]
 
 class TupleTrait(HasTraits):
 
     value = Tuple(Int)
 
 class TestTupleTrait(TraitTestBase):
 
     obj = TupleTrait()
 
     _default_value = None
     _good_values = [(1,), None,(0,)]
     _bad_values = [10, (1,2), [1],('a'), ()]
 
     def test_invalid_args(self):
         self.assertRaises(TypeError, Tuple, 5)
         self.assertRaises(TypeError, Tuple, default_value='hello')
         t = Tuple(Int, CBytes, default_value=(1,5))
 
 class LooseTupleTrait(HasTraits):
 
     value = Tuple((1,2,3))
 
 class TestLooseTupleTrait(TraitTestBase):
 
     obj = LooseTupleTrait()
 
     _default_value = (1,2,3)
     _good_values = [(1,), None, (0,), tuple(range(5)), tuple('hello'), ('a',5), ()]
     _bad_values = [10, 'hello', [1], []]
 
     def test_invalid_args(self):
         self.assertRaises(TypeError, Tuple, 5)
         self.assertRaises(TypeError, Tuple, default_value='hello')
         t = Tuple(Int, CBytes, default_value=(1,5))
 
 
 class MultiTupleTrait(HasTraits):
 
     value = Tuple(Int, Bytes, default_value=[99,b'bottles'])
 
 class TestMultiTuple(TraitTestBase):
 
     obj = MultiTupleTrait()
 
     _default_value = (99,b'bottles')
     _good_values = [(1,b'a'), (2,b'b')]
     _bad_values = ((),10, b'a', (1,b'a',3), (b'a',1), (1, u'a'))
 
 class CRegExpTrait(HasTraits):
 
     value = CRegExp(r'')
 
 class TestCRegExp(TraitTestBase):
 
     def coerce(self, value):
         return re.compile(value)
 
     obj = CRegExpTrait()
 
     _default_value = re.compile(r'')
     _good_values = [r'\d+', re.compile(r'\d+')]
     _bad_values = [r'(', None, ()]
 
 class DictTrait(HasTraits):
     value = Dict()
 
 def test_dict_assignment():
     d = dict()
     c = DictTrait()
     c.value = d
     d['a'] = 5
     nt.assert_equal(d, c.value)
     nt.assert_true(c.value is d)