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|
import functools
from unittest import TestCase
from rules.predicates import (
NO_VALUE,
Predicate,
always_allow,
always_deny,
always_false,
always_true,
predicate,
)
class PredicateKwonlyTests(TestCase):
def test_predicate_kwargonly(self):
def p(foo, *, bar):
return True
with self.assertRaises(TypeError):
predicate(p)
def p2(foo, *a, bar):
return True
with self.assertRaises(TypeError):
predicate(p2)
def p3(foo, *, bar="bar"):
return True
# Should not fail
predicate(p3)
class PredicateTests(TestCase):
def test_always_true(self):
assert always_true()
def test_always_false(self):
assert not always_false()
def test_always_allow(self):
assert always_allow()
def test_always_deny(self):
assert not always_deny()
def test_lambda_predicate(self):
p = Predicate(lambda x: x == "a")
assert p.name == "<lambda>"
assert p.num_args == 1
assert p("a")
def test_lambda_predicate_custom_name(self):
p = Predicate(lambda x: x == "a", name="mypred")
assert p.name == "mypred"
assert p.num_args == 1
assert p("a")
def test_function_predicate(self):
def mypred(x):
return x == "a"
p = Predicate(mypred)
assert p.name == "mypred"
assert p.num_args == 1
assert p("a")
def test_function_predicate_custom_name(self):
def mypred(x):
return x == "a"
p = Predicate(mypred, name="foo")
assert p.name == "foo"
assert p.num_args == 1
assert p("a")
def test_partial_function_predicate(self):
def mypred(one, two, three):
return one < two < three
p = Predicate(functools.partial(mypred, 1))
assert p.name == "mypred"
assert p.num_args == 2 # 3 - 1 partial
assert p(2, 3)
p = Predicate(functools.partial(mypred, 1, 2))
assert p.name == "mypred"
assert p.num_args == 1 # 3 - 2 partial
assert p(3)
def test_method_predicate(self):
class SomeClass(object):
def some_method(self, arg1, arg2):
return arg1 == arg2
obj = SomeClass()
p = Predicate(obj.some_method)
assert p.name == "some_method"
assert p.num_args == 2
assert p(2, 2)
def test_partial_method_predicate(self):
class SomeClass(object):
def some_method(self, arg1, arg2):
return arg1 == arg2
obj = SomeClass()
p = Predicate(functools.partial(obj.some_method, 2))
assert p.name == "some_method"
assert p.num_args == 1
assert p(2)
def test_class_predicate(self):
class callableclass(object):
def __call__(self, arg1, arg2):
return arg1 == arg2
fn = callableclass()
p = Predicate(fn)
assert p.name == "callableclass"
assert p.num_args == 2
assert p("a", "a")
def test_class_predicate_custom_name(self):
class callableclass(object):
def __call__(self, arg):
return arg == "a"
fn = callableclass()
p = Predicate(fn, name="bar")
assert p.name == "bar"
assert p.num_args == 1
assert p("a")
def test_predicate_predicate(self):
def mypred(x):
return x == "a"
p = Predicate(Predicate(mypred))
assert p.name == "mypred"
assert p.num_args == 1
assert p("a")
def test_predicate_predicate_custom_name(self):
def mypred(x):
return x == "a"
p = Predicate(Predicate(mypred, name="foo"))
assert p.name == "foo"
assert p.num_args == 1
assert p("a")
def test_predicate_bind(self):
@predicate(bind=True)
def is_bound(self):
return self is is_bound
assert is_bound()
p = None
def mypred(self):
return self is p
p = Predicate(mypred, bind=True)
assert p()
def test_decorator(self):
@predicate
def mypred(arg1, arg2):
return True
assert mypred.name == "mypred"
assert mypred.num_args == 2
def test_decorator_noargs(self):
@predicate()
def mypred(arg1, arg2):
return True
assert mypred.name == "mypred"
assert mypred.num_args == 2
def test_decorator_custom_name(self):
@predicate("foo")
def mypred():
return True
assert mypred.name == "foo"
assert mypred.num_args == 0
@predicate(name="bar")
def myotherpred():
return False
assert myotherpred.name == "bar"
assert myotherpred.num_args == 0
def test_repr(self):
@predicate
def mypred(arg1, arg2):
return True
assert repr(mypred).startswith("<Predicate:mypred object at 0x")
def test_AND(self):
p_AND1 = always_true & always_false
assert not p_AND1()
assert p_AND1.name == "(always_true & always_false)"
p_AND2 = always_false & always_true
assert not p_AND2()
assert p_AND2.name == "(always_false & always_true)"
p_AND3 = always_true & always_true
assert p_AND3()
assert p_AND3.name == "(always_true & always_true)"
p_AND4 = always_false & always_false
assert not p_AND4()
assert p_AND4.name == "(always_false & always_false)"
def test_OR(self):
p_OR1 = always_true | always_false
assert p_OR1()
assert p_OR1.name == "(always_true | always_false)"
p_OR2 = always_false | always_true
assert p_OR2()
assert p_OR2.name == "(always_false | always_true)"
p_OR3 = always_true | always_true
assert p_OR3()
assert p_OR3.name == "(always_true | always_true)"
p_OR4 = always_false | always_false
assert not p_OR4()
assert p_OR4.name == "(always_false | always_false)"
def test_XOR(self):
p_XOR1 = always_true ^ always_false
assert p_XOR1()
assert p_XOR1.name == "(always_true ^ always_false)"
p_XOR2 = always_false ^ always_true
assert p_XOR2()
assert p_XOR2.name == "(always_false ^ always_true)"
p_XOR3 = always_true ^ always_true
assert not p_XOR3()
assert p_XOR3.name == "(always_true ^ always_true)"
p_XOR4 = always_false ^ always_false
assert not p_XOR4()
assert p_XOR4.name == "(always_false ^ always_false)"
def test_INV(self):
p_INV1 = ~always_true
assert not p_INV1()
assert p_INV1.name == "~always_true"
p_INV2 = ~always_false
assert p_INV2()
assert p_INV2.name == "~always_false"
p_INV3 = ~(~always_true)
assert p_INV3()
assert p_INV3.name == "always_true"
p_INV4 = ~(~always_false)
assert not p_INV4()
assert p_INV4.name == "always_false"
def test_var_args(self):
@predicate
def p(*args, **kwargs):
assert len(args) > 0
assert len(kwargs) == 0
assert p.num_args == 0
p.test("a")
p.test("a", "b")
def test_no_args(self):
@predicate
def p(*args, **kwargs):
assert len(args) == 0
assert len(kwargs) == 0
assert p.num_args == 0
p.test()
def test_one_arg(self):
@predicate
def p(a=None, *args, **kwargs):
assert len(args) == 0
assert len(kwargs) == 0
assert a == "a"
assert p.num_args == 1
p.test("a")
def test_two_args(self):
@predicate
def p(a=None, b=None, *args, **kwargs):
assert len(args) == 0
assert len(kwargs) == 0
assert a == "a"
assert b == "b"
assert p.num_args == 2
p.test("a", "b")
def test_no_mask(self):
@predicate
def p(a=None, b=None, *args, **kwargs):
assert len(args) == 0
assert len(kwargs) == 1
assert "c" in kwargs
assert a == "a"
assert b == "b"
p("a", b="b", c="c")
def test_no_value_marker(self):
@predicate
def p(a, b=None):
assert a == "a"
assert b is None
assert not NO_VALUE
p.test("a")
p.test("a", NO_VALUE)
def test_short_circuit(self):
@predicate
def skipped_predicate(self):
return None
@predicate
def shorted_predicate(self):
raise Exception("this predicate should not be evaluated")
assert (always_false & shorted_predicate).test() is False
assert (always_true | shorted_predicate).test() is True
def raises(pred):
try:
pred.test()
return False
except Exception as e:
return "evaluated" in str(e)
assert raises(always_true & shorted_predicate)
assert raises(always_false | shorted_predicate)
assert raises(skipped_predicate & shorted_predicate)
assert raises(skipped_predicate | shorted_predicate)
def test_skip_predicate(self):
@predicate(bind=True)
def requires_two_args(self, a, b):
return a == b if len(self.context.args) > 1 else None
@predicate
def passthrough(a):
return a
assert (requires_two_args & passthrough).test(True, True) is True
assert (requires_two_args & passthrough).test(True, False) is False
# because requires_two_args is called with only one argument
# its result is not taken into account, only the result of the
# other predicate matters.
assert (requires_two_args & passthrough).test(True) is True
assert (requires_two_args & passthrough).test(False) is False
assert (requires_two_args | passthrough).test(True) is True
assert (requires_two_args | passthrough).test(False) is False
# test that order does not matter
assert (passthrough & requires_two_args).test(True) is True
assert (passthrough & requires_two_args).test(False) is False
assert (passthrough | requires_two_args).test(True) is True
assert (passthrough | requires_two_args).test(False) is False
# test that inversion does not modify the result
assert (~requires_two_args & passthrough).test(True) is True
assert (~requires_two_args & passthrough).test(False) is False
assert (~requires_two_args | passthrough).test(True) is True
assert (~requires_two_args | passthrough).test(False) is False
assert (passthrough & ~requires_two_args).test(True) is True
assert (passthrough & ~requires_two_args).test(False) is False
assert (passthrough | ~requires_two_args).test(True) is True
assert (passthrough | ~requires_two_args).test(False) is False
# test that when all predicates are skipped, result is False
assert requires_two_args.test(True) is False
assert (requires_two_args | requires_two_args).test(True) is False
assert (requires_two_args & requires_two_args).test(True) is False
# test that a skipped predicate doesn't alter the result at all
assert (requires_two_args | requires_two_args | passthrough).test(True) is True
assert (requires_two_args & requires_two_args & passthrough).test(True) is True
def test_invocation_context(self):
@predicate
def p1():
assert id(p1.context) == id(p2.context)
assert p1.context.args == ("a",)
return True
@predicate
def p2():
assert id(p1.context) == id(p2.context)
assert p2.context.args == ("a",)
return True
p = p1 & p2
assert p.test("a")
assert p.context is None
def test_invocation_context_nested(self):
@predicate
def p1():
assert p1.context.args == ("b1",)
return True
@predicate
def p2():
assert p2.context.args == ("b2",)
return True
@predicate
def p():
assert p1.context.args == ("a",)
return p1.test("b1") & p2.test("b2")
assert p.test("a")
assert p.context is None
def test_invocation_context_storage(self):
@predicate
def p1(a):
p1.context["p1.a"] = a
return True
@predicate
def p2(a):
return p2.context["p1.a"] == a
p = p1 & p2
assert p.test("a")
|
