| from test import support |
| import unittest |
| from types import MethodType |
| |
| def funcattrs(**kwds): |
| def decorate(func): |
| func.__dict__.update(kwds) |
| return func |
| return decorate |
| |
| class MiscDecorators (object): |
| @staticmethod |
| def author(name): |
| def decorate(func): |
| func.__dict__['author'] = name |
| return func |
| return decorate |
| |
| # ----------------------------------------------- |
| |
| class DbcheckError (Exception): |
| def __init__(self, exprstr, func, args, kwds): |
| # A real version of this would set attributes here |
| Exception.__init__(self, "dbcheck %r failed (func=%s args=%s kwds=%s)" % |
| (exprstr, func, args, kwds)) |
| |
| |
| def dbcheck(exprstr, globals=None, locals=None): |
| "Decorator to implement debugging assertions" |
| def decorate(func): |
| expr = compile(exprstr, "dbcheck-%s" % func.__name__, "eval") |
| def check(*args, **kwds): |
| if not eval(expr, globals, locals): |
| raise DbcheckError(exprstr, func, args, kwds) |
| return func(*args, **kwds) |
| return check |
| return decorate |
| |
| # ----------------------------------------------- |
| |
| def countcalls(counts): |
| "Decorator to count calls to a function" |
| def decorate(func): |
| func_name = func.__name__ |
| counts[func_name] = 0 |
| def call(*args, **kwds): |
| counts[func_name] += 1 |
| return func(*args, **kwds) |
| call.__name__ = func_name |
| return call |
| return decorate |
| |
| # ----------------------------------------------- |
| |
| def memoize(func): |
| saved = {} |
| def call(*args): |
| try: |
| return saved[args] |
| except KeyError: |
| res = func(*args) |
| saved[args] = res |
| return res |
| except TypeError: |
| # Unhashable argument |
| return func(*args) |
| call.__name__ = func.__name__ |
| return call |
| |
| # ----------------------------------------------- |
| |
| class TestDecorators(unittest.TestCase): |
| |
| def test_single(self): |
| class C(object): |
| @staticmethod |
| def foo(): return 42 |
| self.assertEqual(C.foo(), 42) |
| self.assertEqual(C().foo(), 42) |
| |
| def check_wrapper_attrs(self, method_wrapper, format_str): |
| def func(x): |
| return x |
| wrapper = method_wrapper(func) |
| |
| self.assertIs(wrapper.__func__, func) |
| self.assertIs(wrapper.__wrapped__, func) |
| |
| for attr in ('__module__', '__qualname__', '__name__', |
| '__doc__', '__annotations__'): |
| self.assertIs(getattr(wrapper, attr), |
| getattr(func, attr)) |
| |
| self.assertEqual(repr(wrapper), format_str.format(func)) |
| return wrapper |
| |
| def test_staticmethod(self): |
| wrapper = self.check_wrapper_attrs(staticmethod, '<staticmethod({!r})>') |
| |
| # bpo-43682: Static methods are callable since Python 3.10 |
| self.assertEqual(wrapper(1), 1) |
| |
| def test_classmethod(self): |
| wrapper = self.check_wrapper_attrs(classmethod, '<classmethod({!r})>') |
| |
| self.assertRaises(TypeError, wrapper, 1) |
| |
| def test_dotted(self): |
| decorators = MiscDecorators() |
| @decorators.author('Cleese') |
| def foo(): return 42 |
| self.assertEqual(foo(), 42) |
| self.assertEqual(foo.author, 'Cleese') |
| |
| def test_argforms(self): |
| # A few tests of argument passing, as we use restricted form |
| # of expressions for decorators. |
| |
| def noteargs(*args, **kwds): |
| def decorate(func): |
| setattr(func, 'dbval', (args, kwds)) |
| return func |
| return decorate |
| |
| args = ( 'Now', 'is', 'the', 'time' ) |
| kwds = dict(one=1, two=2) |
| @noteargs(*args, **kwds) |
| def f1(): return 42 |
| self.assertEqual(f1(), 42) |
| self.assertEqual(f1.dbval, (args, kwds)) |
| |
| @noteargs('terry', 'gilliam', eric='idle', john='cleese') |
| def f2(): return 84 |
| self.assertEqual(f2(), 84) |
| self.assertEqual(f2.dbval, (('terry', 'gilliam'), |
| dict(eric='idle', john='cleese'))) |
| |
| @noteargs(1, 2,) |
| def f3(): pass |
| self.assertEqual(f3.dbval, ((1, 2), {})) |
| |
| def test_dbcheck(self): |
| @dbcheck('args[1] is not None') |
| def f(a, b): |
| return a + b |
| self.assertEqual(f(1, 2), 3) |
| self.assertRaises(DbcheckError, f, 1, None) |
| |
| def test_memoize(self): |
| counts = {} |
| |
| @memoize |
| @countcalls(counts) |
| def double(x): |
| return x * 2 |
| self.assertEqual(double.__name__, 'double') |
| |
| self.assertEqual(counts, dict(double=0)) |
| |
| # Only the first call with a given argument bumps the call count: |
| # |
| self.assertEqual(double(2), 4) |
| self.assertEqual(counts['double'], 1) |
| self.assertEqual(double(2), 4) |
| self.assertEqual(counts['double'], 1) |
| self.assertEqual(double(3), 6) |
| self.assertEqual(counts['double'], 2) |
| |
| # Unhashable arguments do not get memoized: |
| # |
| self.assertEqual(double([10]), [10, 10]) |
| self.assertEqual(counts['double'], 3) |
| self.assertEqual(double([10]), [10, 10]) |
| self.assertEqual(counts['double'], 4) |
| |
| def test_errors(self): |
| |
| # Test SyntaxErrors: |
| for stmt in ("x,", "x, y", "x = y", "pass", "import sys"): |
| compile(stmt, "test", "exec") # Sanity check. |
| with self.assertRaises(SyntaxError): |
| compile(f"@{stmt}\ndef f(): pass", "test", "exec") |
| |
| # Test TypeErrors that used to be SyntaxErrors: |
| for expr in ("1.+2j", "[1, 2][-1]", "(1, 2)", "True", "...", "None"): |
| compile(expr, "test", "eval") # Sanity check. |
| with self.assertRaises(TypeError): |
| exec(f"@{expr}\ndef f(): pass") |
| |
| def unimp(func): |
| raise NotImplementedError |
| context = dict(nullval=None, unimp=unimp) |
| |
| for expr, exc in [ ("undef", NameError), |
| ("nullval", TypeError), |
| ("nullval.attr", AttributeError), |
| ("unimp", NotImplementedError)]: |
| codestr = "@%s\ndef f(): pass\nassert f() is None" % expr |
| code = compile(codestr, "test", "exec") |
| self.assertRaises(exc, eval, code, context) |
| |
| def test_expressions(self): |
| for expr in ( |
| "(x,)", "(x, y)", "x := y", "(x := y)", "x @y", "(x @ y)", "x[0]", |
| "w[x].y.z", "w + x - (y + z)", "x(y)()(z)", "[w, x, y][z]", "x.y", |
| ): |
| compile(f"@{expr}\ndef f(): pass", "test", "exec") |
| |
| def test_double(self): |
| class C(object): |
| @funcattrs(abc=1, xyz="haha") |
| @funcattrs(booh=42) |
| def foo(self): return 42 |
| self.assertEqual(C().foo(), 42) |
| self.assertEqual(C.foo.abc, 1) |
| self.assertEqual(C.foo.xyz, "haha") |
| self.assertEqual(C.foo.booh, 42) |
| |
| def test_order(self): |
| # Test that decorators are applied in the proper order to the function |
| # they are decorating. |
| def callnum(num): |
| """Decorator factory that returns a decorator that replaces the |
| passed-in function with one that returns the value of 'num'""" |
| def deco(func): |
| return lambda: num |
| return deco |
| @callnum(2) |
| @callnum(1) |
| def foo(): return 42 |
| self.assertEqual(foo(), 2, |
| "Application order of decorators is incorrect") |
| |
| def test_eval_order(self): |
| # Evaluating a decorated function involves four steps for each |
| # decorator-maker (the function that returns a decorator): |
| # |
| # 1: Evaluate the decorator-maker name |
| # 2: Evaluate the decorator-maker arguments (if any) |
| # 3: Call the decorator-maker to make a decorator |
| # 4: Call the decorator |
| # |
| # When there are multiple decorators, these steps should be |
| # performed in the above order for each decorator, but we should |
| # iterate through the decorators in the reverse of the order they |
| # appear in the source. |
| |
| actions = [] |
| |
| def make_decorator(tag): |
| actions.append('makedec' + tag) |
| def decorate(func): |
| actions.append('calldec' + tag) |
| return func |
| return decorate |
| |
| class NameLookupTracer (object): |
| def __init__(self, index): |
| self.index = index |
| |
| def __getattr__(self, fname): |
| if fname == 'make_decorator': |
| opname, res = ('evalname', make_decorator) |
| elif fname == 'arg': |
| opname, res = ('evalargs', str(self.index)) |
| else: |
| assert False, "Unknown attrname %s" % fname |
| actions.append('%s%d' % (opname, self.index)) |
| return res |
| |
| c1, c2, c3 = map(NameLookupTracer, [ 1, 2, 3 ]) |
| |
| expected_actions = [ 'evalname1', 'evalargs1', 'makedec1', |
| 'evalname2', 'evalargs2', 'makedec2', |
| 'evalname3', 'evalargs3', 'makedec3', |
| 'calldec3', 'calldec2', 'calldec1' ] |
| |
| actions = [] |
| @c1.make_decorator(c1.arg) |
| @c2.make_decorator(c2.arg) |
| @c3.make_decorator(c3.arg) |
| def foo(): return 42 |
| self.assertEqual(foo(), 42) |
| |
| self.assertEqual(actions, expected_actions) |
| |
| # Test the equivalence claim in chapter 7 of the reference manual. |
| # |
| actions = [] |
| def bar(): return 42 |
| bar = c1.make_decorator(c1.arg)(c2.make_decorator(c2.arg)(c3.make_decorator(c3.arg)(bar))) |
| self.assertEqual(bar(), 42) |
| self.assertEqual(actions, expected_actions) |
| |
| def test_wrapped_descriptor_inside_classmethod(self): |
| class BoundWrapper: |
| def __init__(self, wrapped): |
| self.__wrapped__ = wrapped |
| |
| def __call__(self, *args, **kwargs): |
| return self.__wrapped__(*args, **kwargs) |
| |
| class Wrapper: |
| def __init__(self, wrapped): |
| self.__wrapped__ = wrapped |
| |
| def __get__(self, instance, owner): |
| bound_function = self.__wrapped__.__get__(instance, owner) |
| return BoundWrapper(bound_function) |
| |
| def decorator(wrapped): |
| return Wrapper(wrapped) |
| |
| class Class: |
| @decorator |
| @classmethod |
| def inner(cls): |
| # This should already work. |
| return 'spam' |
| |
| @classmethod |
| @decorator |
| def outer(cls): |
| # Raised TypeError with a message saying that the 'Wrapper' |
| # object is not callable. |
| return 'eggs' |
| |
| self.assertEqual(Class.inner(), 'spam') |
| self.assertEqual(Class.outer(), 'eggs') |
| self.assertEqual(Class().inner(), 'spam') |
| self.assertEqual(Class().outer(), 'eggs') |
| |
| def test_wrapped_classmethod_inside_classmethod(self): |
| class MyClassMethod1: |
| def __init__(self, func): |
| self.func = func |
| |
| def __call__(self, cls): |
| if hasattr(self.func, '__get__'): |
| return self.func.__get__(cls, cls)() |
| return self.func(cls) |
| |
| def __get__(self, instance, owner=None): |
| if owner is None: |
| owner = type(instance) |
| return MethodType(self, owner) |
| |
| class MyClassMethod2: |
| def __init__(self, func): |
| if isinstance(func, classmethod): |
| func = func.__func__ |
| self.func = func |
| |
| def __call__(self, cls): |
| return self.func(cls) |
| |
| def __get__(self, instance, owner=None): |
| if owner is None: |
| owner = type(instance) |
| return MethodType(self, owner) |
| |
| for myclassmethod in [MyClassMethod1, MyClassMethod2]: |
| class A: |
| @myclassmethod |
| def f1(cls): |
| return cls |
| |
| @classmethod |
| @myclassmethod |
| def f2(cls): |
| return cls |
| |
| @myclassmethod |
| @classmethod |
| def f3(cls): |
| return cls |
| |
| @classmethod |
| @classmethod |
| def f4(cls): |
| return cls |
| |
| @myclassmethod |
| @MyClassMethod1 |
| def f5(cls): |
| return cls |
| |
| @myclassmethod |
| @MyClassMethod2 |
| def f6(cls): |
| return cls |
| |
| self.assertIs(A.f1(), A) |
| self.assertIs(A.f2(), A) |
| self.assertIs(A.f3(), A) |
| self.assertIs(A.f4(), A) |
| self.assertIs(A.f5(), A) |
| self.assertIs(A.f6(), A) |
| a = A() |
| self.assertIs(a.f1(), A) |
| self.assertIs(a.f2(), A) |
| self.assertIs(a.f3(), A) |
| self.assertIs(a.f4(), A) |
| self.assertIs(a.f5(), A) |
| self.assertIs(a.f6(), A) |
| |
| def f(cls): |
| return cls |
| |
| self.assertIs(myclassmethod(f).__get__(a)(), A) |
| self.assertIs(myclassmethod(f).__get__(a, A)(), A) |
| self.assertIs(myclassmethod(f).__get__(A, A)(), A) |
| self.assertIs(myclassmethod(f).__get__(A)(), type(A)) |
| self.assertIs(classmethod(f).__get__(a)(), A) |
| self.assertIs(classmethod(f).__get__(a, A)(), A) |
| self.assertIs(classmethod(f).__get__(A, A)(), A) |
| self.assertIs(classmethod(f).__get__(A)(), type(A)) |
| |
| class TestClassDecorators(unittest.TestCase): |
| |
| def test_simple(self): |
| def plain(x): |
| x.extra = 'Hello' |
| return x |
| @plain |
| class C(object): pass |
| self.assertEqual(C.extra, 'Hello') |
| |
| def test_double(self): |
| def ten(x): |
| x.extra = 10 |
| return x |
| def add_five(x): |
| x.extra += 5 |
| return x |
| |
| @add_five |
| @ten |
| class C(object): pass |
| self.assertEqual(C.extra, 15) |
| |
| def test_order(self): |
| def applied_first(x): |
| x.extra = 'first' |
| return x |
| def applied_second(x): |
| x.extra = 'second' |
| return x |
| @applied_second |
| @applied_first |
| class C(object): pass |
| self.assertEqual(C.extra, 'second') |
| |
| if __name__ == "__main__": |
| unittest.main() |
