from test import support import types import unittest class FuncAttrsTest(unittest.TestCase): def setUp(self): class F: def a(self): pass def b(): return 3 self.fi = F() self.F = F self.b = b def cannot_set_attr(self, obj, name, value, exceptions): 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.assertTrue('known_attr' in dir(self.b), "set attributes not in dir listing of method") # Test on underlying function object of method self.F.a.known_attr = 7 self.assertTrue('known_attr' in dir(self.fi.a), "set attribute on function " "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___code__(self): def test(): pass self.assertEqual(test(), None) test.__code__ = self.b.__code__ self.assertEqual(test(), 3) # self.b always returns 3, arbitrarily def test___globals__(self): self.assertIs(self.b.__globals__, globals()) self.cannot_set_attr(self.b, '__globals__', 2, (AttributeError, TypeError)) def test___closure__(self): a = 12 def f(): print(a) c = f.__closure__ self.assertTrue(isinstance(c, tuple)) self.assertEqual(len(c), 1) # don't have a type object handy self.assertEqual(c[0].__class__.__name__, "cell") self.cannot_set_attr(f, "__closure__", c, AttributeError) def test_empty_cell(self): def f(): print(a) try: f.__closure__[0].cell_contents except ValueError: pass else: self.fail("shouldn't be able to read an empty cell") a = 12 def test___name__(self): self.assertEqual(self.b.__name__, 'b') self.b.__name__ = 'c' self.assertEqual(self.b.__name__, 'c') self.b.__name__ = 'd' self.assertEqual(self.b.__name__, 'd') # __name__ and __name__ must be a string self.cannot_set_attr(self.b, '__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, {'__builtins__': {}}) # Test on methods, too self.assertEqual(self.fi.a.__name__, 'a') self.cannot_set_attr(self.fi.a, "__name__", 'a', AttributeError) def test___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.__code__), types.CodeType) self.assertEqual(c(), 7) self.assertEqual(d(), 8) d.__code__ = c.__code__ self.assertEqual(c.__code__, d.__code__) self.assertEqual(c(), 7) # self.assertEqual(d(), 7) try: b.__code__ = c.__code__ except ValueError: pass else: self.fail("__code__ with different numbers of free vars should " "not be possible") try: e.__code__ = d.__code__ except ValueError: pass else: self.fail("__code__ with different numbers of free vars should " "not be possible") def test_blank_func_defaults(self): self.assertEqual(self.b.__defaults__, None) del self.b.__defaults__ self.assertEqual(self.b.__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.__defaults__, None) self.assertEqual(second_func.__defaults__, (1, 2)) first_func.__defaults__ = (1, 2) self.assertEqual(first_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.__defaults__ self.assertEqual(second_func.__defaults__, None) try: second_func() except TypeError: pass else: self.fail("__defaults__ does not update; deleting it does not " "remove requirement") class InstancemethodAttrTest(FuncAttrsTest): def test___class__(self): self.assertEqual(self.fi.a.__self__.__class__, self.F) self.cannot_set_attr(self.fi.a, "__class__", self.F, TypeError) def test___func__(self): self.assertEqual(self.fi.a.__func__, self.F.a) self.cannot_set_attr(self.fi.a, "__func__", self.F.a, AttributeError) def test___self__(self): self.assertEqual(self.fi.a.__self__, self.fi) self.cannot_set_attr(self.fi.a, "__self__", self.fi, AttributeError) def test___func___non_method(self): # Behavior should be the same when a method is added via an attr # assignment self.fi.id = types.MethodType(id, self.fi) self.assertEqual(self.fi.id(), id(self.fi)) # Test usage try: self.fi.id.unknown_attr except AttributeError: pass else: self.fail("using unknown attributes should raise AttributeError") # Test assignment and deletion self.cannot_set_attr(self.fi.id, 'unknown_attr', 2, AttributeError) class ArbitraryFunctionAttrTest(FuncAttrsTest): def test_set_attr(self): self.b.known_attr = 7 self.assertEqual(self.b.known_attr, 7) try: self.fi.a.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_unset_attr(self): for func in [self.b, self.fi.a]: try: func.non_existent_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) from collections import UserDict d = UserDict({'known_attr': 7}) self.cannot_set_attr(self.fi.a.__func__, '__dict__', d, TypeError) def test_setting_dict_to_valid(self): d = {'known_attr': 7} self.b.__dict__ = d # Test assignment self.assertIs(d, self.b.__dict__) # ... and on all the different ways of referencing the method's func self.F.a.__dict__ = d self.assertIs(d, self.fi.a.__func__.__dict__) self.assertIs(d, self.fi.a.__dict__) # Test value self.assertEqual(self.b.known_attr, 7) self.assertEqual(self.b.__dict__['known_attr'], 7) # ... and again, on all the different method's names self.assertEqual(self.fi.a.__func__.known_attr, 7) self.assertEqual(self.fi.a.known_attr, 7) def test_delete___dict__(self): try: del self.b.__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) docstr = "A test method that does nothing" self.b.__doc__ = docstr self.F.a.__doc__ = docstr self.assertEqual(self.b.__doc__, docstr) self.assertEqual(self.fi.a.__doc__, docstr) 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) def cell(value): """Create a cell containing the given value.""" def f(): print(a) a = value return f.__closure__[0] def empty_cell(empty=True): """Create an empty cell.""" def f(): print(a) # the intent of the following line is simply "if False:"; it's # spelt this way to avoid the danger that a future optimization # might simply remove an "if False:" code block. if not empty: a = 1729 return f.__closure__[0] class CellTest(unittest.TestCase): def test_comparison(self): # These tests are here simply to exercise the comparison code; # their presence should not be interpreted as providing any # guarantees about the semantics (or even existence) of cell # comparisons in future versions of CPython. self.assertTrue(cell(2) < cell(3)) self.assertTrue(empty_cell() < cell('saturday')) self.assertTrue(empty_cell() == empty_cell()) self.assertTrue(cell(-36) == cell(-36.0)) self.assertTrue(cell(True) > empty_cell()) class StaticMethodAttrsTest(unittest.TestCase): def test_func_attribute(self): def f(): pass c = classmethod(f) self.assertTrue(c.__func__ is f) s = staticmethod(f) self.assertTrue(s.__func__ is f) def test_main(): support.run_unittest(FunctionPropertiesTest, InstancemethodAttrTest, ArbitraryFunctionAttrTest, FunctionDictsTest, FunctionDocstringTest, CellTest, StaticMethodAttrsTest) if __name__ == "__main__": test_main()