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#  All rights reserved.
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import unittest

from ..trait_types import Int
from ..has_traits import HasTraits


class Foo(HasTraits):

    bar = Int

    def _bar_default(self):
        return 4


class TestTraitDefaultInitializer(unittest.TestCase):
    """ Test basic usage of the default method.

    """

    def test_default_value(self):
        foo = Foo()
        self.assertEqual(foo.bar, 4)

    def test_default_value_override(self):
        foo = Foo(bar=3)
        self.assertEqual(foo.bar, 3)

    def test_reset_to_default(self):
        foo = Foo(bar=3)
        foo.reset_traits(traits=['bar'])
        self.assertEqual(foo.bar, 4)

    def test_error_propagation_in_default_methods(self):

        class FooException(Foo):

            def _bar_default(self):
                1 / 0

        foo = FooException()
        self.assertRaises(ZeroDivisionError, lambda: foo.bar)

        class FooKeyError(Foo):

            def _bar_default(self):
                raise KeyError()

        # Check that KeyError is propagated (issue #70).
        foo = FooKeyError()
        self.assertRaises(KeyError, lambda: foo.bar)
