from test import test_support

import types

import unittest

class FuncAttrsTest(unittest.TestCase):

    def setUp(self):

        class F:

            def a(self):

                pass

        def b():

            return 3

        self.f = F

        self.fi = F()

        self.b = b

    def cannot_set_attr(self,obj, name, value, exceptions):

        # This method is not called as a test (name doesn't start with 'test'),

        # but may be used by other tests.

        try: setattr(obj, name, value)

        except exceptions: pass

        else: self.fail("shouldn't be able to set %s to %r" % (name, value))

        try: delattr(obj, name)

        except exceptions: pass

        else: self.fail("shouldn't be able to del %s" % name)

class FunctionPropertiesTest(FuncAttrsTest):

    # Include the external setUp method that is common to all tests

    def test_module(self):

        self.assertEqual(self.b.__module__, __name__)

    def test_dir_includes_correct_attrs(self):

        self.b.known_attr = 7

        self.assert_('known_attr' in dir(self.b),

            "set attributes not in dir listing of method")

        # Test on underlying function object of method

        self.f.a.im_func.known_attr = 7

        self.assert_('known_attr' in dir(self.f.a),

            "set attribute on unbound method implementation in class not in "

                     "dir")

        self.assert_('known_attr' in dir(self.fi.a),

            "set attribute on unbound method implementations, should show up"

                     " in next dir")

    def test_duplicate_function_equality(self):

        # Body of `duplicate' is the exact same as self.b

        def duplicate():

            'my docstring'

            return 3

        self.assertNotEqual(self.b, duplicate)

    def test_copying_func_code(self):

        def test(): pass

        self.assertEqual(test(), None)

        test.func_code = self.b.func_code

        self.assertEqual(test(), 3) # self.b always returns 3, arbitrarily

    def test_func_globals(self):

        self.assertEqual(self.b.func_globals, globals())

        self.cannot_set_attr(self.b, 'func_globals', 2, TypeError)

    def test_func_name(self):

        self.assertEqual(self.b.__name__, 'b')

        self.assertEqual(self.b.func_name, 'b')

        self.b.__name__ = 'c'

        self.assertEqual(self.b.__name__, 'c')

        self.assertEqual(self.b.func_name, 'c')

        self.b.func_name = 'd'

        self.assertEqual(self.b.__name__, 'd')

        self.assertEqual(self.b.func_name, 'd')

        # __name__ and func_name must be a string

        self.cannot_set_attr(self.b, '__name__', 7, TypeError)

        self.cannot_set_attr(self.b, 'func_name', 7, TypeError)

        # __name__ must be available when in restricted mode. Exec will raise

        # AttributeError if __name__ is not available on f.

        s = """def f(): pass\nf.__name__"""

        exec s in {'__builtins__': {}}

        # Test on methods, too

        self.assertEqual(self.f.a.__name__, 'a')

        self.assertEqual(self.fi.a.__name__, 'a')

        self.cannot_set_attr(self.f.a, "__name__", 'a', AttributeError)

        self.cannot_set_attr(self.fi.a, "__name__", 'a', AttributeError)

    def test_func_code(self):

        num_one, num_two = 7, 8

        def a(): pass

        def b(): return 12

        def c(): return num_one

        def d(): return num_two

        def e(): return num_one, num_two

        for func in [a, b, c, d, e]:

            self.assertEqual(type(func.func_code), types.CodeType)

        self.assertEqual(c(), 7)

        self.assertEqual(d(), 8)

        d.func_code = c.func_code

        self.assertEqual(c.func_code, d.func_code)

        self.assertEqual(c(), 7)

        # self.assertEqual(d(), 7)

        try: b.func_code = c.func_code

        except ValueError: pass

        else: self.fail(

            "func_code with different numbers of free vars should not be "

            "possible")

        try: e.func_code = d.func_code

        except ValueError: pass

        else: self.fail(

            "func_code with different numbers of free vars should not be "

            "possible")

    def test_blank_func_defaults(self):

        self.assertEqual(self.b.func_defaults, None)

        del self.b.func_defaults

        self.assertEqual(self.b.func_defaults, None)

    def test_func_default_args(self):

        def first_func(a, b):

            return a+b

        def second_func(a=1, b=2):

            return a+b

        self.assertEqual(first_func.func_defaults, None)

        self.assertEqual(second_func.func_defaults, (1, 2))

        first_func.func_defaults = (1, 2)

        self.assertEqual(first_func.func_defaults, (1, 2))

        self.assertEqual(first_func(), 3)

        self.assertEqual(first_func(3), 5)

        self.assertEqual(first_func(3, 5), 8)

        del second_func.func_defaults

        self.assertEqual(second_func.func_defaults, None)

        try: second_func()

        except TypeError: pass

        else: self.fail(

            "func_defaults does not update; deleting it does not remove "

            "requirement")

class ImplicitReferencesTest(FuncAttrsTest):

    def test_im_class(self):

        self.assertEqual(self.f.a.im_class, self.f)

        self.assertEqual(self.fi.a.im_class, self.f)

        self.cannot_set_attr(self.f.a, "im_class", self.f, TypeError)

        self.cannot_set_attr(self.fi.a, "im_class", self.f, TypeError)

    def test_im_func(self):

        self.f.b = self.b

        self.assertEqual(self.f.b.im_func, self.b)

        self.assertEqual(self.fi.b.im_func, self.b)

        self.cannot_set_attr(self.f.b, "im_func", self.b, TypeError)

        self.cannot_set_attr(self.fi.b, "im_func", self.b, TypeError)

    def test_im_self(self):

        self.assertEqual(self.f.a.im_self, None)

        self.assertEqual(self.fi.a.im_self, self.fi)

        self.cannot_set_attr(self.f.a, "im_self", None, TypeError)

        self.cannot_set_attr(self.fi.a, "im_self", self.fi, TypeError)

    def test_im_func_non_method(self):

        # Behavior should be the same when a method is added via an attr

        # assignment

        self.f.id = types.MethodType(id, None, self.f)

        self.assertEqual(self.fi.id(), id(self.fi))

        self.assertNotEqual(self.fi.id(), id(self.f))

        # Test usage

        try: self.f.id.unknown_attr

        except AttributeError: pass

        else: self.fail("using unknown attributes should raise AttributeError")

        # Test assignment and deletion

        self.cannot_set_attr(self.f.id, 'unknown_attr', 2, AttributeError)

        self.cannot_set_attr(self.fi.id, 'unknown_attr', 2, AttributeError)

    def test_implicit_method_properties(self):

        self.f.a.im_func.known_attr = 7

        self.assertEqual(self.f.a.known_attr, 7)

        self.assertEqual(self.fi.a.known_attr, 7)

class ArbitraryFunctionAttrTest(FuncAttrsTest):

    def test_set_attr(self):

        self.b.known_attr = 7

        self.assertEqual(self.b.known_attr, 7)

        for func in [self.f.a, self.fi.a]:

            try: func.known_attr = 7

            except AttributeError: pass

            else: self.fail("setting attributes on methods should raise error")

    def test_delete_unknown_attr(self):

        try: del self.b.unknown_attr

        except AttributeError: pass

        else: self.fail("deleting unknown attribute should raise TypeError")

    def test_setting_attrs_duplicates(self):

        try: self.f.a.klass = self.f

        except AttributeError: pass

        else: self.fail("setting arbitrary attribute in unbound function "

                        " should raise AttributeError")

        self.f.a.im_func.klass = self.f

        for method in [self.f.a, self.fi.a, self.fi.a.im_func]:

            self.assertEqual(method.klass, self.f)

    def test_unset_attr(self):

        for func in [self.b, self.f.a, self.fi.a]:

            try:  func.non_existant_attr

            except AttributeError: pass

            else: self.fail("using unknown attributes should raise "

                            "AttributeError")

class FunctionDictsTest(FuncAttrsTest):

    def test_setting_dict_to_invalid(self):

        self.cannot_set_attr(self.b, '__dict__', None, TypeError)

        self.cannot_set_attr(self.b, 'func_dict', None, TypeError)

        from UserDict import UserDict

        d = UserDict({'known_attr': 7})

        self.cannot_set_attr(self.f.a.im_func, '__dict__', d, TypeError)

        self.cannot_set_attr(self.fi.a.im_func, '__dict__', d, TypeError)

    def test_setting_dict_to_valid(self):

        d = {'known_attr': 7}

        self.b.__dict__ = d

        # Setting dict is only possible on the underlying function objects

        self.f.a.im_func.__dict__ = d

        # Test assignment

        self.assertEqual(d, self.b.__dict__)

        self.assertEqual(d, self.b.func_dict)

        # ... and on all the different ways of referencing the method's func

        self.assertEqual(d, self.f.a.im_func.__dict__)

        self.assertEqual(d, self.f.a.__dict__)

        self.assertEqual(d, self.fi.a.im_func.__dict__)

        self.assertEqual(d, self.fi.a.__dict__)

        # Test value

        self.assertEqual(self.b.known_attr, 7)

        self.assertEqual(self.b.__dict__['known_attr'], 7)

        self.assertEqual(self.b.func_dict['known_attr'], 7)

        # ... and again, on all the different method's names

        self.assertEqual(self.f.a.im_func.known_attr, 7)

        self.assertEqual(self.f.a.known_attr, 7)

        self.assertEqual(self.fi.a.im_func.known_attr, 7)

        self.assertEqual(self.fi.a.known_attr, 7)

    def test_delete_func_dict(self):

        try: del self.b.__dict__

        except TypeError: pass

        else: self.fail("deleting function dictionary should raise TypeError")

        try: del self.b.func_dict

        except TypeError: pass

        else: self.fail("deleting function dictionary should raise TypeError")

    def test_unassigned_dict(self):

        self.assertEqual(self.b.__dict__, {})

    def test_func_as_dict_key(self):

        value = "Some string"

        d = {}

        d[self.b] = value

        self.assertEqual(d[self.b], value)

class FunctionDocstringTest(FuncAttrsTest):

    def test_set_docstring_attr(self):

        self.assertEqual(self.b.__doc__, None)

        self.assertEqual(self.b.func_doc, None)

        docstr = "A test method that does nothing"

        self.b.__doc__ = self.f.a.im_func.__doc__ = docstr

        self.assertEqual(self.b.__doc__, docstr)

        self.assertEqual(self.b.func_doc, docstr)

        self.assertEqual(self.f.a.__doc__, docstr)

        self.assertEqual(self.fi.a.__doc__, docstr)

        self.cannot_set_attr(self.f.a, "__doc__", docstr, AttributeError)

        self.cannot_set_attr(self.fi.a, "__doc__", docstr, AttributeError)

    def test_delete_docstring(self):

        self.b.__doc__ = "The docstring"

        del self.b.__doc__

        self.assertEqual(self.b.__doc__, None)

        self.assertEqual(self.b.func_doc, None)

        self.b.func_doc = "The docstring"

        del self.b.func_doc

        self.assertEqual(self.b.__doc__, None)

        self.assertEqual(self.b.func_doc, None)

def test_main():

    test_support.run_unittest(FunctionPropertiesTest, ImplicitReferencesTest,

                              ArbitraryFunctionAttrTest, FunctionDictsTest,

                              FunctionDocstringTest)

if __name__ == "__main__":

    test_main()