from functools import update_wrapper, wraps from unittest import TestCase from django.contrib.admin.views.decorators import staff_member_required from django.contrib.auth.decorators import ( login_required, permission_required, user_passes_test, ) from django.http import HttpResponse from django.test import SimpleTestCase from django.utils.decorators import method_decorator from django.utils.functional import keep_lazy, keep_lazy_text, lazy from django.utils.safestring import mark_safe from django.views.decorators.cache import cache_control, cache_page, never_cache from django.views.decorators.http import ( condition, require_GET, require_http_methods, require_POST, require_safe, ) from django.views.decorators.vary import vary_on_cookie, vary_on_headers def fully_decorated(request): """Expected __doc__""" return HttpResponse("dummy") fully_decorated.anything = "Expected __dict__" def compose(*functions): # compose(f, g)(*args, **kwargs) == f(g(*args, **kwargs)) functions = list(reversed(functions)) def _inner(*args, **kwargs): result = functions[0](*args, **kwargs) for f in functions[1:]: result = f(result) return result return _inner full_decorator = compose( # django.views.decorators.http require_http_methods(["GET"]), require_GET, require_POST, require_safe, condition(lambda r: None, lambda r: None), # django.views.decorators.vary vary_on_headers("Accept-language"), vary_on_cookie, # django.views.decorators.cache cache_page(60 * 15), cache_control(private=True), never_cache, # django.contrib.auth.decorators # Apply user_passes_test twice to check #9474 user_passes_test(lambda u: True), login_required, permission_required("change_world"), # django.contrib.admin.views.decorators staff_member_required, # django.utils.functional keep_lazy(HttpResponse), keep_lazy_text, lazy, # django.utils.safestring mark_safe, ) fully_decorated = full_decorator(fully_decorated) class DecoratorsTest(TestCase): def test_attributes(self): """ Built-in decorators set certain attributes of the wrapped function. """ self.assertEqual(fully_decorated.__name__, "fully_decorated") self.assertEqual(fully_decorated.__doc__, "Expected __doc__") self.assertEqual(fully_decorated.__dict__["anything"], "Expected __dict__") def test_user_passes_test_composition(self): """ The user_passes_test decorator can be applied multiple times (#9474). """ def test1(user): user.decorators_applied.append("test1") return True def test2(user): user.decorators_applied.append("test2") return True def callback(request): return request.user.decorators_applied callback = user_passes_test(test1)(callback) callback = user_passes_test(test2)(callback) class DummyUser: pass class DummyRequest: pass request = DummyRequest() request.user = DummyUser() request.user.decorators_applied = [] response = callback(request) self.assertEqual(response, ["test2", "test1"]) # For testing method_decorator, a decorator that assumes a single argument. # We will get type arguments if there is a mismatch in the number of arguments. def simple_dec(func): @wraps(func) def wrapper(arg): return func("test:" + arg) return wrapper simple_dec_m = method_decorator(simple_dec) # For testing method_decorator, two decorators that add an attribute to the function def myattr_dec(func): def wrapper(*args, **kwargs): return func(*args, **kwargs) wrapper.myattr = True return wrapper myattr_dec_m = method_decorator(myattr_dec) def myattr2_dec(func): def wrapper(*args, **kwargs): return func(*args, **kwargs) wrapper.myattr2 = True return wrapper myattr2_dec_m = method_decorator(myattr2_dec) class ClsDec: def __init__(self, myattr): self.myattr = myattr def __call__(self, f): def wrapper(): return f() and self.myattr return update_wrapper(wrapper, f) class MethodDecoratorTests(SimpleTestCase): """ Tests for method_decorator """ def test_preserve_signature(self): class Test: @simple_dec_m def say(self, arg): return arg self.assertEqual("test:hello", Test().say("hello")) def test_preserve_attributes(self): # Sanity check myattr_dec and myattr2_dec @myattr_dec def func(): pass self.assertIs(getattr(func, "myattr", False), True) @myattr2_dec def func(): pass self.assertIs(getattr(func, "myattr2", False), True) @myattr_dec @myattr2_dec def func(): pass self.assertIs(getattr(func, "myattr", False), True) self.assertIs(getattr(func, "myattr2", False), False) # Decorate using method_decorator() on the method. class TestPlain: @myattr_dec_m @myattr2_dec_m def method(self): "A method" pass # Decorate using method_decorator() on both the class and the method. # The decorators applied to the methods are applied before the ones # applied to the class. @method_decorator(myattr_dec_m, "method") class TestMethodAndClass: @method_decorator(myattr2_dec_m) def method(self): "A method" pass # Decorate using an iterable of function decorators. @method_decorator((myattr_dec, myattr2_dec), "method") class TestFunctionIterable: def method(self): "A method" pass # Decorate using an iterable of method decorators. decorators = (myattr_dec_m, myattr2_dec_m) @method_decorator(decorators, "method") class TestMethodIterable: def method(self): "A method" pass tests = ( TestPlain, TestMethodAndClass, TestFunctionIterable, TestMethodIterable, ) for Test in tests: with self.subTest(Test=Test): self.assertIs(getattr(Test().method, "myattr", False), True) self.assertIs(getattr(Test().method, "myattr2", False), True) self.assertIs(getattr(Test.method, "myattr", False), True) self.assertIs(getattr(Test.method, "myattr2", False), True) self.assertEqual(Test.method.__doc__, "A method") self.assertEqual(Test.method.__name__, "method") def test_new_attribute(self): """A decorator that sets a new attribute on the method.""" def decorate(func): func.x = 1 return func class MyClass: @method_decorator(decorate) def method(self): return True obj = MyClass() self.assertEqual(obj.method.x, 1) self.assertIs(obj.method(), True) def test_bad_iterable(self): decorators = {myattr_dec_m, myattr2_dec_m} msg = "'set' object is not subscriptable" with self.assertRaisesMessage(TypeError, msg): @method_decorator(decorators, "method") class TestIterable: def method(self): "A method" pass # Test for argumented decorator def test_argumented(self): class Test: @method_decorator(ClsDec(False)) def method(self): return True self.assertIs(Test().method(), False) def test_descriptors(self): def original_dec(wrapped): def _wrapped(arg): return wrapped(arg) return _wrapped method_dec = method_decorator(original_dec) class bound_wrapper: def __init__(self, wrapped): self.wrapped = wrapped self.__name__ = wrapped.__name__ def __call__(self, arg): return self.wrapped(arg) def __get__(self, instance, cls=None): return self class descriptor_wrapper: def __init__(self, wrapped): self.wrapped = wrapped self.__name__ = wrapped.__name__ def __get__(self, instance, cls=None): return bound_wrapper(self.wrapped.__get__(instance, cls)) class Test: @method_dec @descriptor_wrapper def method(self, arg): return arg self.assertEqual(Test().method(1), 1) def test_class_decoration(self): """ @method_decorator can be used to decorate a class and its methods. """ def deco(func): def _wrapper(*args, **kwargs): return True return _wrapper @method_decorator(deco, name="method") class Test: def method(self): return False self.assertTrue(Test().method()) def test_tuple_of_decorators(self): """ @method_decorator can accept a tuple of decorators. """ def add_question_mark(func): def _wrapper(*args, **kwargs): return func(*args, **kwargs) + "?" return _wrapper def add_exclamation_mark(func): def _wrapper(*args, **kwargs): return func(*args, **kwargs) + "!" return _wrapper # The order should be consistent with the usual order in which # decorators are applied, e.g. # @add_exclamation_mark # @add_question_mark # def func(): # ... decorators = (add_exclamation_mark, add_question_mark) @method_decorator(decorators, name="method") class TestFirst: def method(self): return "hello world" class TestSecond: @method_decorator(decorators) def method(self): return "hello world" self.assertEqual(TestFirst().method(), "hello world?!") self.assertEqual(TestSecond().method(), "hello world?!") def test_invalid_non_callable_attribute_decoration(self): """ @method_decorator on a non-callable attribute raises an error. """ msg = ( "Cannot decorate 'prop' as it isn't a callable attribute of " " (1)" ) with self.assertRaisesMessage(TypeError, msg): @method_decorator(lambda: None, name="prop") class Test: prop = 1 @classmethod def __module__(cls): return "tests" def test_invalid_method_name_to_decorate(self): """ @method_decorator on a nonexistent method raises an error. """ msg = ( "The keyword argument `name` must be the name of a method of the " "decorated class: . Got 'nonexistent_method' instead" ) with self.assertRaisesMessage(ValueError, msg): @method_decorator(lambda: None, name="nonexistent_method") class Test: @classmethod def __module__(cls): return "tests" def test_wrapper_assignments(self): """@method_decorator preserves wrapper assignments.""" func_name = None func_module = None def decorator(func): @wraps(func) def inner(*args, **kwargs): nonlocal func_name, func_module func_name = getattr(func, "__name__", None) func_module = getattr(func, "__module__", None) return func(*args, **kwargs) return inner class Test: @method_decorator(decorator) def method(self): return "tests" Test().method() self.assertEqual(func_name, "method") self.assertIsNotNone(func_module)