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("<html><body>dummy</body></html>")
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 "
"<class 'Test'> (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: <class 'Test'>. 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)