# pylint: disable=too-many-public-methods, missing-docstring, eval-used, too-many-lines, no-self-use, disallowed-name, unspecified-encoding

"""
Unit tests for simpleeval.
--------------------------

Most of this stuff is pretty basic.

"""

import ast
import gc
import operator
import os
import platform
import sys
import unittest
import warnings

import simpleeval
from simpleeval import (
    BASIC_ALLOWED_ATTRS,
    AttributeDoesNotExist,
    EvalWithCompoundTypes,
    FeatureNotAvailable,
    FunctionNotDefined,
    InvalidExpression,
    ModuleWrapper,
    NameNotDefined,
    OperatorNotDefined,
    SimpleEval,
    simple_eval,
)


class DRYTest(unittest.TestCase):
    """Stuff we need to do every test, let's do here instead..
    Don't Repeat Yourself."""

    def setUp(self):
        """initialize a SimpleEval"""
        self.s = SimpleEval()

    def t(self, expr, should_be):  # pylint: disable=invalid-name
        """test an evaluation of an expression against an expected answer"""
        return self.assertEqual(self.s.eval(expr), should_be)


class TestBasic(DRYTest):
    """Simple expressions."""

    def test_maths_with_ints(self):
        """simple maths expressions"""

        self.t("21 + 21", 42)
        self.t("6*7", 42)
        self.t("20 + 1 + (10*2) + 1", 42)
        self.t("100/10", 10)
        self.t("12*12", 144)
        self.t("2 ** 10", 1024)
        self.t("100 % 9", 1)
        self.t("10 << 10", 10 << 10)
        self.t("10 << 10", 10240)
        self.t("1000 >> 2", 1000 >> 2)
        self.t("1000 >> 2", 250)

    def test_bools_and_or(self):
        self.t('True and ""', "")
        self.t("True and False", False)
        self.t("True or False", True)
        self.t("False or False", False)
        self.t("1 - 1 or 21", 21)
        self.t("1 - 1 and 11", 0)
        self.t("110 == 100 + 10 and True", True)
        self.t("110 != 100 + 10 and True", False)
        self.t("False or 42", 42)

        self.t("False or None", None)
        self.t("None or None", None)

        self.s.names = {"out": True, "position": 3}
        self.t(
            "(out and position <=6 and -10) or (out and position > 6 and -5) or (not out and 15)",
            -10,
        )

    def test_bit_ops(self):
        self.t("62 ^ 20", 42)
        self.t("62 ^ 100", 90)
        self.t("8 | 34", 42)
        self.t("100 & 63", 36)
        self.t("~ -43", 42)

    def test_not(self):
        self.t("not False", True)
        self.t("not True", False)
        self.t("not 0", True)
        self.t("not 1", False)

    def test_maths_with_floats(self):
        self.t("11.02 - 9.1", 1.92)
        self.t("29.1+39", 68.1)

    def test_comparisons(self):
        # GT & LT:
        self.t("1 > 0", True)
        self.t("100000 < 28", False)
        self.t("-2 < 11", True)
        self.t("+2 < 5", True)
        self.t("0 == 0", True)

        # GtE, LtE
        self.t("-2 <= -2", True)
        self.t("2 >= 2", True)
        self.t("1 >= 12", False)
        self.t("1.09 <= 1967392", True)

        self.t("1 < 2 < 3 < 4", 1 < 2 < 3 < 4)
        self.t("1 < 2 > 3 < 4", 1 < 2 > 3 < 4)

        # pylint: disable=comparison-with-itself
        self.t("1<2<1+1", 1 < 2 < 1 + 1)
        self.t("1 == 1 == 2", 1 == 1 == 2)
        self.t("1 == 1 < 2", 1 == 1 < 2)

    def test_mixed_comparisons(self):
        self.t("1 > 0.999999", True)
        self.t("1 == True", True)  # Note ==, not 'is'.
        self.t("0 == False", True)  # Note ==, not 'is'.
        self.t("False == False", True)
        self.t("False < True", True)

    def test_if_else(self):
        """x if y else z"""

        # and test if/else expressions:
        self.t("'a' if 1 == 1 else 'b'", "a")
        self.t("'a' if 1 > 2 else 'b'", "b")

        # and more complex expressions:
        self.t("'a' if 4 < 1 else 'b' if 1 == 2 else 'c'", "c")

    def test_default_conversions(self):
        """conversion between types"""

        self.t('int("20") + int(0.22*100)', 42)
        self.t('float("42")', 42.0)
        self.t('"Test Stuff!" + str(11)', "Test Stuff!11")

    def test_slicing(self):
        self.s.operators[ast.Slice] = (
            operator.getslice if hasattr(operator, "getslice") else operator.getitem
        )
        self.t("'hello'[1]", "e")
        self.t("'hello'[:]", "hello")
        self.t("'hello'[:3]", "hel")
        self.t("'hello'[3:]", "lo")
        self.t("'hello'[::2]", "hlo")
        self.t("'hello'[::-1]", "olleh")
        self.t("'hello'[3::]", "lo")
        self.t("'hello'[:3:]", "hel")
        self.t("'hello'[1:3]", "el")
        self.t("'hello'[1:3:]", "el")
        self.t("'hello'[1::2]", "el")
        self.t("'hello'[:1:2]", "h")
        self.t("'hello'[1:3:1]", "el")
        self.t("'hello'[1:3:2]", "e")

        with self.assertRaises(IndexError):
            self.t("'hello'[90]", 0)

        self.t('"spam" not in "my breakfast"', True)
        self.t('"silly" in "ministry of silly walks"', True)
        self.t('"I" not in "team"', True)
        self.t('"U" in "RUBBISH"', True)

    def test_is(self):
        self.t("1 is 1", True)
        self.t("1 is 2", False)
        self.t('1 is "a"', False)
        self.t("1 is None", False)
        self.t("None is None", True)

        self.t("1 is not 1", False)
        self.t("1 is not 2", True)
        self.t('1 is not "a"', True)
        self.t("1 is not None", True)
        self.t("None is not None", False)

    def test_fstring(self):
        if sys.version_info >= (3, 6, 0):
            self.t('f""', "")
            self.t('f"stuff"', "stuff")
            self.t('f"one is {1} and two is {2}"', "one is 1 and two is 2")
            self.t('f"1+1 is {1+1}"', "1+1 is 2")
            self.t("f\"{'dramatic':!<11}\"", "dramatic!!!")

    def test_set_not_allowed(self):
        with self.assertRaises(FeatureNotAvailable):
            self.t("{22}", False)

    def test_empty_string_not_allowed(self):
        with self.assertRaises(InvalidExpression):
            self.t("", False)


class TestEvaluator(DRYTest):
    """Tests for how the SimpleEval class does things"""

    def test_only_evaluate_first_statement(self):
        # it only evaluates the first statement:
        with warnings.catch_warnings(record=True) as ws:
            warnings.simplefilter("always")
            self.t("11; x = 21; x + x", 11)
        self.assertIsInstance(ws[0].message, simpleeval.MultipleExpressions)

    def test_parse_and_use_previously_parsed(self):
        expr = "x + x"
        nodes = self.s.parse(expr)
        self.s.names = {"x": 21}
        self.assertEqual(self.s.eval(expr, nodes), 42)

        # This can all be done with unittest.mock.patch in python3.3+ - when we drop
        # python2 - we can drop this nonsense.
        class MockedCalled(Exception):
            pass

        def go_boom(*args, **kwargs):
            raise MockedCalled("you should never see this.")

        self.s.parse = go_boom

        # Prove the mock is installed in self.s
        with self.assertRaises(MockedCalled):
            self.s.eval("10 + 10")

        # Prove it's not installed in the actual SimpleEval
        SimpleEval().eval("10 + 10")

        # Now running .eval with a previously parsed
        self.assertEqual(self.s.eval(expr, previously_parsed=nodes), 42)

        self.s.names = {"x": 100}
        self.assertEqual(self.s.eval(expr, nodes), 200)


class TestFunctions(DRYTest):
    """Functions for expressions to play with"""

    def test_load_file(self):
        """add in a function which loads data from an external file."""

        # write to the file:

        with open("testfile.txt", "w") as f:
            f.write("42")

        # define the function we'll send to the eval'er

        def load_file(filename):
            """load a file and return its contents"""
            with open(filename) as f2:
                return f2.read()

        # simple load:

        self.s.functions = {"read": load_file}
        self.t("read('testfile.txt')", "42")

        # and we should have *replaced* the default functions. Let's check:

        with self.assertRaises(simpleeval.FunctionNotDefined):
            self.t("int(read('testfile.txt'))", 42)

        # OK, so we can load in the default functions as well...

        self.s.functions.update(simpleeval.DEFAULT_FUNCTIONS)

        # now it works:

        self.t("int(read('testfile.txt'))", 42)

        os.remove("testfile.txt")

    def test_randoms(self):
        """test the rand() and randint() functions"""

        i = self.s.eval("randint(1000)")
        self.assertEqual(type(i), int)
        self.assertLessEqual(i, 1000)

        f = self.s.eval("rand()")
        self.assertEqual(type(f), float)

        self.t("randint(20)<20", True)
        self.t("rand()<1.0", True)

        # I don't know how to further test these functions.  Ideas?

    def test_methods(self):
        self.t('"WORD".lower()', "word")
        x = simpleeval.DISALLOW_METHODS
        simpleeval.DISALLOW_METHODS = []
        self.t('"{}:{}".format(1, 2)', "1:2")
        simpleeval.DISALLOW_METHODS = x

    def test_function_args_none(self):
        def foo():
            return 42

        self.s.functions["foo"] = foo
        self.t("foo()", 42)

    def test_function_args_required(self):
        def foo(to_return):
            return to_return

        self.s.functions["foo"] = foo
        with self.assertRaises(TypeError):
            self.t("foo()", 42)

        self.t("foo(12)", 12)
        self.t("foo(to_return=100)", 100)

    def test_function_args_defaults(self):
        def foo(to_return=9999):
            return to_return

        self.s.functions["foo"] = foo
        self.t("foo()", 9999)

        self.t("foo(12)", 12)
        self.t("foo(to_return=100)", 100)

    def test_function_args_bothtypes(self):
        def foo(mult, to_return=100):
            return to_return * mult

        self.s.functions["foo"] = foo
        with self.assertRaises(TypeError):
            self.t("foo()", 9999)

        self.t("foo(2)", 200)

        with self.assertRaises(TypeError):
            self.t("foo(to_return=100)", 100)

        self.t("foo(4, to_return=4)", 16)
        self.t("foo(mult=2, to_return=4)", 8)
        self.t("foo(2, 10)", 20)

    def test_function_with_list_args(self):
        # Regression test, makes sure we can pass lists (non-hashable) items as
        # kwargs to functions.

        def func(*args, **kwargs):
            return 42

        simple_eval("test(boo=x)", functions={"test": func}, names={"x": [1, 2]})


class TestOperators(DRYTest):
    """Test adding in new operators, removing them, make sure it works."""

    # TODO
    pass


class TestNewFeatures(DRYTest):
    """Tests which will break when new features are added..."""

    def test_lambda(self):
        with self.assertRaises(FeatureNotAvailable):
            self.t("lambda x:22", None)

    def test_lambda_application(self):
        with self.assertRaises(FeatureNotAvailable):
            self.t("(lambda x:22)(44)", None)


class TestTryingToBreakOut(DRYTest):
    """Test various weird methods to break the security sandbox..."""

    def test_import(self):
        """usual suspect. import"""
        # cannot import things:
        with self.assertRaises(FeatureNotAvailable):
            self.t("import sys", None)

    def test_long_running(self):
        """exponent operations can take a long time."""
        old_max = simpleeval.MAX_POWER

        self.t("9**9**5", 9**9**5)

        with self.assertRaises(simpleeval.NumberTooHigh):
            self.t("9**9**8", 0)

        # and does limiting work?

        simpleeval.MAX_POWER = 100

        with self.assertRaises(simpleeval.NumberTooHigh):
            self.t("101**2", 0)

        # good, so set it back:

        simpleeval.MAX_POWER = old_max

    def test_large_shifts(self):
        """Trying to << or >> large amounts can be too slow."""
        with self.assertRaises(simpleeval.NumberTooHigh):
            self.t("1<<25000", 0)

        with self.assertRaises(simpleeval.NumberTooHigh):
            self.t("%s<<25" % (simpleeval.MAX_SHIFT_BASE + 1), 0)

        with self.assertRaises(simpleeval.NumberTooHigh):
            self.t("1>>25000", 0)

        with self.assertRaises(simpleeval.NumberTooHigh):
            self.t("%s>>25" % (simpleeval.MAX_SHIFT_BASE + 1), 0)

        # and test we can change it:

        old_max = simpleeval.MAX_SHIFT
        simpleeval.MAX_SHIFT = 100

        with self.assertRaises(simpleeval.NumberTooHigh):
            self.t("1<<250", 0)

        with self.assertRaises(simpleeval.NumberTooHigh):
            self.t("1000>>250", 0)

        # good, so set it back.

        simpleeval.MAX_SHIFT = old_max

        self.t("1<<250", 1 << 250)

    def test_encode_bignums(self):
        # thanks gk
        with self.assertRaises(simpleeval.IterableTooLong):
            self.t('(1).from_bytes(("123123123123123123123123").encode()*999999, "big")', 0)

    def test_string_length(self):
        with self.assertRaises(simpleeval.IterableTooLong):
            self.t("50000*'text'", 0)

        with self.assertRaises(simpleeval.IterableTooLong):
            self.t("'text'*50000", 0)

        with self.assertRaises(simpleeval.IterableTooLong):
            self.t("('text'*50000)*1000", 0)

        with self.assertRaises(simpleeval.IterableTooLong):
            self.t("(50000*'text')*1000", 0)

        self.t("'stuff'*20000", 20000 * "stuff")

        self.t("20000*'stuff'", 20000 * "stuff")

        with self.assertRaises(simpleeval.IterableTooLong):
            self.t("('stuff'*20000) + ('stuff'*20000) ", 0)

        with self.assertRaises(simpleeval.IterableTooLong):
            self.t("'stuff'*100000", 100000 * "stuff")

        with self.assertRaises(simpleeval.IterableTooLong):
            self.t("'" + (10000 * "stuff") + "'*100", 0)

        with self.assertRaises(simpleeval.IterableTooLong):
            self.t("'" + (50000 * "stuff") + "'", 0)

        if sys.version_info >= (3, 6, 0):
            with self.assertRaises(simpleeval.IterableTooLong):
                self.t("f'{\"foo\"*50000}'", 0)

    def test_bytes_array_test(self):
        self.t("'20000000000000000000'.encode() * 5000", "20000000000000000000".encode() * 5000)

        with self.assertRaises(simpleeval.IterableTooLong):
            self.t("'123121323123131231223'.encode() * 5000", 20)

    def test_list_length_test(self):
        self.t("'spam spam spam'.split() * 5000", ["spam", "spam", "spam"] * 5000)

        with self.assertRaises(simpleeval.IterableTooLong):
            self.t("('spam spam spam' * 5000).split() * 5000", None)

    def test_function_globals_breakout(self):
        """by accessing function.__globals__ or func_..."""
        # thanks perkinslr.

        self.s.functions["x"] = lambda y: y + y
        self.t("x(100)", 200)

        with self.assertRaises(simpleeval.FeatureNotAvailable):
            self.t("x.__globals__", None)

        class EscapeArtist(object):
            @staticmethod
            def trapdoor():
                return 42

            @staticmethod
            def _quasi_private():
                return 84

        self.s.names["houdini"] = EscapeArtist()

        with self.assertRaises(simpleeval.FeatureNotAvailable):
            self.t("houdini.trapdoor.__globals__", 0)

        with self.assertRaises(simpleeval.FeatureNotAvailable):
            self.t("houdini.trapdoor.func_globals", 0)

        with self.assertRaises(simpleeval.FeatureNotAvailable):
            self.t("houdini._quasi_private()", 0)

        # and test for changing '_' to '__':

        dis = simpleeval.DISALLOW_PREFIXES
        simpleeval.DISALLOW_PREFIXES = ["func_"]

        self.t("houdini.trapdoor()", 42)
        self.t("houdini._quasi_private()", 84)

        # and return things to normal

        simpleeval.DISALLOW_PREFIXES = dis

    def test_mro_breakout(self):
        class Blah(object):
            x = 42

        self.s.names["b"] = Blah

        with self.assertRaises(simpleeval.FeatureNotAvailable):
            self.t("b.mro()", None)

    def test_builtins_private_access(self):
        # explicit attempt of the exploit from perkinslr
        with self.assertRaises(simpleeval.FeatureNotAvailable):
            self.t(
                "True.__class__.__class__.__base__.__subclasses__()[-1]"
                ".__init__.func_globals['sys'].exit(1)",
                42,
            )

    def test_string_format(self):
        # python has so many ways to break out!
        with self.assertRaises(simpleeval.FeatureNotAvailable):
            self.t('"{string.__class__}".format(string="things")', 0)

        with self.assertRaises(simpleeval.FeatureNotAvailable):
            self.s.names["x"] = {"a": 1}
            self.t('"{a.__class__}".format_map(x)', 0)

        if sys.version_info >= (3, 6, 0):
            self.s.names["x"] = 42

            with self.assertRaises(simpleeval.FeatureNotAvailable):
                self.t('f"{x.__class__}"', 0)

            self.s.names["x"] = lambda y: y

            with self.assertRaises(simpleeval.FeatureNotAvailable):
                self.t('f"{x.__globals__}"', 0)

            class EscapeArtist(object):
                @staticmethod
                def trapdoor():
                    return 42

                @staticmethod
                def _quasi_private():
                    return 84

            self.s.names["houdini"] = EscapeArtist()  # let's just retest this, but in a f-string

            with self.assertRaises(simpleeval.FeatureNotAvailable):
                self.t('f"{houdini.trapdoor.__globals__}"', 0)

            with self.assertRaises(simpleeval.FeatureNotAvailable):
                self.t('f"{houdini.trapdoor.func_globals}"', 0)

            with self.assertRaises(simpleeval.FeatureNotAvailable):
                self.t('f"{houdini._quasi_private()}"', 0)

            # and test for changing '_' to '__':

            dis = simpleeval.DISALLOW_PREFIXES
            simpleeval.DISALLOW_PREFIXES = ["func_"]

            self.t('f"{houdini.trapdoor()}"', "42")
            self.t('f"{houdini._quasi_private()}"', "84")

            # and return things to normal

            simpleeval.DISALLOW_PREFIXES = dis

    def test_breakout_via_module_access(self):
        import os.path

        s = SimpleEval(names={"path": os.path})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("path.os.popen('id').read()")

    def test_breakout_via_module_access_attr(self):
        import os.path

        class Foo:
            p = os.path

        s = SimpleEval(names={"thing": Foo()})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("thing.p.os.popen('id').read()")

    def test_breakout_via_disallowed_functions_as_attrs(self):
        class Foo:
            p = exec

        s = SimpleEval(names={"thing": Foo()})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("thing.p('exit')")

    def test_breakout_forbidden_function_in_list(self):
        """Disallowed functions in lists should be blocked"""
        s = SimpleEval(names={"funcs": [exec, eval]})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("funcs[0]('exit')")

        with self.assertRaises(FeatureNotAvailable):
            s.eval("funcs[1]('1+1')")

    def test_breakout_module_in_list(self):
        """Modules in lists should be blocked"""
        import os.path

        s = SimpleEval(names={"things": [os.path, os.system]})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("things[0].os.popen('id').read()")

    def test_breakout_forbidden_function_in_dict_value(self):
        """Disallowed functions as dict values should be blocked"""
        s = SimpleEval(names={"funcs": {"bad": exec, "evil": eval}})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("funcs['bad']('exit')")

        with self.assertRaises(FeatureNotAvailable):
            s.eval("funcs['evil']('1+1')")

    def test_breakout_module_in_dict_value(self):
        """Modules as dict values should be blocked"""
        import os.path

        s = SimpleEval(names={"things": {"p": os.path, "s": os.system}})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("things['p'].os.popen('id').read()")

    def test_breakout_function_returning_forbidden_function(self):
        """Functions returning disallowed functions should be blocked"""

        def get_evil():
            return exec  # pragma: no cover

        s = SimpleEval(names={}, functions={"get_evil": get_evil})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("get_evil()('exit')")

    def test_breakout_function_returning_module(self):
        """Functions returning modules should be blocked"""
        import os.path

        def get_module():
            return os.path

        s = SimpleEval(names={}, functions={"get_module": get_module})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("get_module().os.popen('id').read()")

    def test_dunder_all_in_module(self):
        """__all__ should be blocked (starts with _)"""
        import os

        s = SimpleEval(names={"os": os})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("os.__all__")

    def test_dunder_dict_in_module(self):
        """__dict__ should be blocked (starts with _)"""
        import os

        s = SimpleEval(names={"os": os})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("os.__dict__")

    def test_forbidden_method_in_tuple(self):
        """Disallowed functions in tuples should be blocked"""
        s = SimpleEval(names={"funcs": (exec, eval)})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("funcs[0]('exit')")

    def test_module_in_tuple(self):
        """Modules in tuples should be blocked"""
        import os

        s = SimpleEval(names={"mods": (os.path, os.system)})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("mods[0].os.popen('id').read()")

    def test_breakout_via_nested_container_forbidden_func(self):
        """Disallowed functions nested in containers should be blocked"""
        s = SimpleEval(names={"data": {"nested": {"funcs": [exec]}}})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("data['nested']['funcs'][0]('exit')")

    def test_breakout_via_nested_container_module(self):
        """Modules nested in containers should be blocked"""
        import os

        s = SimpleEval(names={"data": {"mods": {"p": os.path}}})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("data['mods']['p'].os.popen('id').read()")

    def test_forbidden_methods_on_allowed_attrs(self):
        """Disallowed methods listed in DISALLOW_METHODS should be
        blocked"""
        s = SimpleEval()

        # format and format_map are in DISALLOW_METHODS
        with self.assertRaises(FeatureNotAvailable):
            s.eval("'test {0}'.format")

        with self.assertRaises(FeatureNotAvailable):
            s.eval("'test'.format_map({0: 'x'})")

        # __mro__ is in DISALLOW_METHODS
        with self.assertRaises(FeatureNotAvailable):
            s.eval("'test'.mro")

    def test_function_returning_forbidden_method(self):
        """Functions returning disallowed methods should be blocked"""

        def get_exec_module():
            import os  # pragma: no cover

            return os  # pragma: no cover

        s = SimpleEval(names={}, functions={"get_os": get_exec_module})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("get_os().__name__")

    def test_compound_module_submodule_access(self):
        """Accessing submodules of a passed module should be blocked"""
        import os.path

        s = SimpleEval(names={"path": os.path})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("path.os")

    def test_forbidden_func_via_class_method(self):
        """Accessing forbidden functions via class methods should be
        blocked"""

        class Container:
            @staticmethod
            def get_exec():
                return exec  # pragma: no cover

        s = SimpleEval(names={"c": Container()})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("c.get_exec()('exit')")

    def test_module_via_class_method(self):
        """Accessing modules via class methods should be blocked"""
        import os

        class Container:
            @staticmethod
            def get_os():
                return os

        s = SimpleEval(names={"c": Container()})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("c.get_os().popen('id').read()")

    def test_forbidden_func_via_property(self):
        """Accessing forbidden functions via properties should be
        blocked"""

        class Container:
            @property
            def evil(self):
                return exec

        s = SimpleEval(names={"c": Container()})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("c.evil('exit')")

    def test_module_via_property(self):
        """Accessing modules via properties should be blocked"""
        import os

        class Container:
            @property
            def mod(self):
                return os

        s = SimpleEval(names={"c": Container()})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("c.mod.popen('id').read()")

    def test_forbidden_function_direct_from_names(self):
        """Forbidden functions passed directly in names should
        be blocked when accessed"""
        s = SimpleEval(names={"evil": exec})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("evil")

    def test_module_direct_from_names(self):
        """Modules passed directly in names should be blocked
        when accessed"""
        import os

        s = SimpleEval(names={"m": os})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("m")

    def test_forbidden_function_via_callable_name_handler(self):
        """Forbidden functions from callable name handlers should
        be blocked"""

        def name_handler(node):
            if node.id == "evil":
                return exec

        s = SimpleEval(names=name_handler)

        with self.assertRaises(FeatureNotAvailable):
            s.eval("evil")

    def test_module_via_callable_name_handler(self):
        """Modules from callable name handlers should be blocked"""
        import os

        def name_handler(node):
            if node.id == "m":
                return os

        s = SimpleEval(names=name_handler)

        with self.assertRaises(FeatureNotAvailable):
            s.eval("m")

    def test_forbidden_function_passed_to_custom_function(self):
        """Passing forbidden functions to custom functions should be
        blocked - they can be executed by the custom function"""

        def evil_caller(func):
            return func("print('pwned')")  # pragma: no cover

        s = SimpleEval(names={"evil": exec}, functions={"evil_caller": evil_caller})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("evil_caller(evil)")

    def test_module_passed_to_custom_function(self):
        """Passing modules to custom functions should be blocked - they
        can be used by the custom function"""
        import os

        def os_caller(mod):
            return mod.system("id")  # pragma: no cover

        s = SimpleEval(names={"m": os}, functions={"os_caller": os_caller})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("os_caller(m)")  # pragma: no cover

    def test_forbidden_function_in_list_passed_to_custom_function(self):
        """Forbidden functions in containers passed to custom functions
        should be blocked"""

        def extract_and_call(items):
            return items[0]("print('pwned')")  # pragma: no cover

        s = SimpleEval(names={"funcs": [exec, eval]}, functions={"extract": extract_and_call})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("extract(funcs)")

    def test_module_in_list_passed_to_custom_function(self):
        """Modules in containers passed to custom functions should be
        blocked"""
        import os

        def extract_and_use(items):
            return items[0].system("id")  # pragma: no cover

        s = SimpleEval(names={"mods": [os.path, os]}, functions={"extract": extract_and_use})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("extract(mods)")

    def test_forbidden_function_in_dict_passed_to_custom_function(self):
        """Forbidden functions in dicts passed to custom functions should
        be blocked"""

        def extract_and_call(d):
            return d["bad"]("print('pwned')")  # pragma: no cover

        s = SimpleEval(
            names={"funcs": {"bad": exec, "good": print}}, functions={"extract": extract_and_call}
        )

        with self.assertRaises(FeatureNotAvailable):
            s.eval("extract(funcs)")

    def test_module_in_dict_passed_to_custom_function(self):
        """Modules in dicts passed to custom functions should be blocked"""
        import os

        def extract_and_use(d):
            return d["m"].system("id")  # pragma: no cover

        s = SimpleEval(
            names={"mods": {"m": os, "p": os.path}}, functions={"extract": extract_and_use}
        )

        with self.assertRaises(FeatureNotAvailable):
            s.eval("extract(mods)")


class TestModuleWrapper(unittest.TestCase):
    """Test the ModuleWrapper class itself"""

    def test_module_wrapper_requires_module(self):
        """ModuleWrapper should reject non-module types"""
        with self.assertRaises(TypeError):
            ModuleWrapper("not a module")

        with self.assertRaises(TypeError):
            ModuleWrapper(42)

        with self.assertRaises(TypeError):
            ModuleWrapper({})

    def test_module_wrapper_allows_valid_module(self):
        """ModuleWrapper should accept valid modules"""
        import os.path

        wrapper = ModuleWrapper(os.path)
        self.assertIsNotNone(wrapper)

    def test_module_wrapper_blocks_private_attrs(self):
        """ModuleWrapper should block access to private attributes"""
        import os.path

        wrapper = ModuleWrapper(os.path)

        with self.assertRaises(FeatureNotAvailable):
            wrapper.__all__

        with self.assertRaises(FeatureNotAvailable):
            wrapper._internal

    def test_module_wrapper_allows_public_attrs(self):
        """ModuleWrapper should allow access to public attributes"""
        import os.path

        wrapper = ModuleWrapper(os.path)
        # Should not raise
        _ = wrapper.exists

    def test_module_wrapper_blocks_disallowed_methods(self):
        """ModuleWrapper should block access to methods in DISALLOW_METHODS"""
        import os

        wrapper = ModuleWrapper(os)

        with self.assertRaises(FeatureNotAvailable):
            wrapper.mro

    def test_module_wrapper_with_allowed_attrs_allows_whitelisted(self):
        """ModuleWrapper with allowed_attrs should allow whitelisted
        attributes"""
        import os.path

        wrapper = ModuleWrapper(os.path, allowed_attrs={"exists", "join"})

        # Should not raise
        _ = wrapper.exists
        _ = wrapper.join

    def test_module_wrapper_with_allowed_attrs_blocks_non_whitelisted(self):
        """ModuleWrapper with allowed_attrs should block non-whitelisted
        attributes"""
        import os.path

        wrapper = ModuleWrapper(os.path, allowed_attrs={"exists"})

        with self.assertRaises(FeatureNotAvailable):
            wrapper.join

    def test_module_wrapper_getattr_returns_actual_attribute(self):
        """ModuleWrapper.__getattr__ should return the actual module
        attribute"""
        import os.path

        wrapper = ModuleWrapper(os.path)
        result = wrapper.exists

        # Should be the actual function
        self.assertEqual(result, os.path.exists)


class TestModuleWrapperAccess(DRYTest):
    """Test ModuleWrapper integration with SimpleEval"""

    def test_unwrapped_module_blocked(self):
        """Unwrapped modules in names should be blocked"""
        import os.path

        s = SimpleEval(names={"path": os.path})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("path")

    def test_wrapped_module_allowed(self):
        """ModuleWrapper should allow module access in eval"""
        import os.path

        s = SimpleEval(names={"path": ModuleWrapper(os.path)})

        result = s.eval("path.exists('/etc/passwd')")
        self.assertTrue(isinstance(result, bool))

    def test_wrapped_module_private_attrs_blocked(self):
        """ModuleWrapper should block private attrs in eval"""
        import os.path

        s = SimpleEval(names={"path": ModuleWrapper(os.path)})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("path.__all__")

    def test_wrapped_module_with_whitelist(self):
        """ModuleWrapper with whitelist should allow whitelisted attrs"""
        import os.path

        s = SimpleEval(names={"path": ModuleWrapper(os.path, allowed_attrs={"exists"})})

        result = s.eval("path.exists('/etc/passwd')")
        self.assertTrue(isinstance(result, bool))

    def test_wrapped_module_with_whitelist_blocks_others(self):
        """ModuleWrapper with whitelist should block non-whitelisted
        attrs"""
        import os.path

        s = SimpleEval(names={"path": ModuleWrapper(os.path, allowed_attrs={"exists"})})

        with self.assertRaises(FeatureNotAvailable):
            s.eval("path.join('a', 'b')")

    def test_wrapped_module_passed_to_function(self):
        """ModuleWrapper can be passed to custom functions"""

        def process_path(path_mod):
            return path_mod.exists("/etc/passwd")

        import os.path

        s = SimpleEval(names={"path": ModuleWrapper(os.path)}, functions={"process": process_path})

        result = s.eval("process(path)")
        self.assertTrue(isinstance(result, bool))

    def test_wrapped_module_in_container(self):
        """ModuleWrapper can be stored in containers"""
        import os.path

        s = SimpleEval(names={"items": [ModuleWrapper(os.path), 1, 2]})

        result = s.eval("items")
        self.assertEqual(len(result), 3)

    def test_wrapped_module_in_dict_container(self):
        """ModuleWrapper can be stored in dicts"""
        import os.path

        s = SimpleEval(names={"data": {"path": ModuleWrapper(os.path), "value": 42}})

        result = s.eval("data['value']")
        self.assertEqual(result, 42)


class TestCompoundTypes(DRYTest):
    """Test the compound-types edition of the library"""

    def setUp(self):
        self.s = EvalWithCompoundTypes()

    def test_dict(self):
        self.t("{}", {})
        self.t('{"foo": "bar"}', {"foo": "bar"})
        self.t('{"foo": "bar"}["foo"]', "bar")
        self.t("dict()", {})
        self.t("dict(a=1)", {"a": 1})

    def test_dict_contains(self):
        self.t('{"a":22}["a"]', 22)
        with self.assertRaises(KeyError):
            self.t('{"a":22}["b"]', 22)

        self.t('{"a": 24}.get("b", 11)', 11)
        self.t('"a" in {"a": 24}', True)

    def test_dict_star_expression(self):
        self.s.names["x"] = {"a": 1, "b": 2}
        self.t('{"a": 0, **x, "c": 3}', {"a": 1, "b": 2, "c": 3})

        # and multiple star expressions should be fine too...
        self.s.names["y"] = {"x": 1, "y": 2}
        self.t('{"a": 0, **x, **y, "c": 3}', {"a": 1, "b": 2, "c": 3, "x": 1, "y": 2})

    def test_dict_invalid_star_expression(self):
        self.s.names["x"] = {"a": 1, "b": 2}
        self.s.names["y"] = {"x": 1, "y": 2}
        self.s.names["z"] = 42

        with self.assertRaises(TypeError):
            self.t('{"a": 0, **x, **y, **z, "c": 3}', {"a": 1, "b": 2, "c": 3})

    def test_tuple(self):
        self.t("()", ())
        self.t("(1,)", (1,))
        self.t("(1, 2, 3, 4, 5, 6)", (1, 2, 3, 4, 5, 6))
        self.t("(1, 2) + (3, 4)", (1, 2, 3, 4))
        self.t("(1, 2, 3)[1]", 2)
        self.t("tuple()", ())
        self.t('tuple("foo")', ("f", "o", "o"))

    def test_tuple_contains(self):
        self.t('("a","b")[1]', "b")
        with self.assertRaises(IndexError):
            self.t('("a","b")[5]', "b")
        self.t('"a" in ("b","c","a")', True)

    def test_list(self):
        self.t("[]", [])
        self.t("[1]", [1])
        self.t("[1, 2, 3, 4, 5]", [1, 2, 3, 4, 5])
        self.t("[1, 2, 3][1]", 2)
        self.t("list()", [])
        self.t('list("foo")', ["f", "o", "o"])

    def test_list_contains(self):
        self.t('["a","b"][1]', "b")
        with self.assertRaises(IndexError):
            self.t('("a","b")[5]', "b")

        self.t('"b" in ["a","b"]', True)

    def test_list_star_expression(self):
        self.s.names["x"] = [1, 2, 3]
        self.t('["a", *x, "b"]', ["a", 1, 2, 3, "b"])

    def test_list_invalid_star_expression(self):
        self.s.names["x"] = [1, 2, 3]
        self.s.names["y"] = 42

        with self.assertRaises(TypeError):
            self.t('["a", *x, *y, "b"]', ["a", 1, 2, 3, "b"])

    def test_set(self):
        self.t("{1}", {1})
        self.t("{1, 2, 1, 2, 1, 2, 1}", {1, 2})
        self.t("set()", set())
        self.t('set("foo")', {"f", "o"})

        self.t("2 in {1,2,3,4}", True)
        self.t("22 not in {1,2,3,4}", True)

    def test_not(self):
        self.t("not []", True)
        self.t("not [0]", False)
        self.t("not {}", True)
        self.t("not {0: 1}", False)
        self.t("not {0}", False)

    def test_use_func(self):
        self.s = EvalWithCompoundTypes(functions={"map": map, "str": str})
        self.t("list(map(str, [-1, 0, 1]))", ["-1", "0", "1"])
        with self.assertRaises(NameNotDefined):
            self.s.eval("list(map(bad, [-1, 0, 1]))")

        with self.assertRaises(FunctionNotDefined):
            self.s.eval("dir(str)")
        with self.assertRaises(FeatureNotAvailable):
            self.s.eval("str.__dict__")

        self.s = EvalWithCompoundTypes(functions={"dir": dir, "str": str})
        self.t("dir(str)", dir(str))


class TestComprehensions(DRYTest):
    """Test the comprehensions support of the compound-types edition of the class."""

    def setUp(self):
        self.s = EvalWithCompoundTypes()

    def test_basic(self):
        self.t("[a + 1 for a in [1,2,3]]", [2, 3, 4])

    def test_with_self_reference(self):
        self.t("[a + a for a in [1,2,3]]", [2, 4, 6])

    def test_with_if(self):
        self.t("[a for a in [1,2,3,4,5] if a <= 3]", [1, 2, 3])

    def test_with_multiple_if(self):
        self.t("[a for a in [1,2,3,4,5] if a <= 3 and a > 1 ]", [2, 3])

    def test_attr_access_fails(self):
        with self.assertRaises(FeatureNotAvailable):
            self.t("[a.__class__ for a in [1,2,3]]", None)

    def test_unpack(self):
        self.t("[a+b for a,b in ((1,2),(3,4))]", [3, 7])

    def test_nested_unpack(self):
        self.t("[a+b+c for a, (b, c) in ((1,(1,1)),(3,(2,2)))]", [3, 7])

    def test_dictcomp_basic(self):
        self.t("{a:a + 1 for a in [1,2,3]}", {1: 2, 2: 3, 3: 4})

    def test_dictcomp_with_self_reference(self):
        self.t("{a:a + a for a in [1,2,3]}", {1: 2, 2: 4, 3: 6})

    def test_dictcomp_with_if(self):
        self.t("{a:a for a in [1,2,3,4,5] if a <= 3}", {1: 1, 2: 2, 3: 3})

    def test_dictcomp_with_multiple_if(self):
        self.t("{a:a for a in [1,2,3,4,5] if a <= 3 and a > 1 }", {2: 2, 3: 3})

    def test_dictcomp_unpack(self):
        self.t("{a:a+b for a,b in ((1,2),(3,4))}", {1: 3, 3: 7})

    def test_dictcomp_nested_unpack(self):
        self.t("{a:a+b+c for a, (b, c) in ((1,(1,1)),(3,(2,2)))}", {1: 3, 3: 7})

    def test_other_places(self):
        self.s.functions = {"sum": sum}
        self.t("sum([a+1 for a in [1,2,3,4,5]])", 20)
        self.t("sum(a+1 for a in [1,2,3,4,5])", 20)

    def test_external_names_work(self):
        self.s.names = {"x": [22, 102, 12.3]}
        self.t("[a/2 for a in x]", [11.0, 51.0, 6.15])

        self.s.names = lambda x: ord(x.id)
        self.t("[a + a for a in [b, c, d]]", [ord(x) * 2 for x in "bcd"])

    def test_multiple_generators(self):
        self.s.functions = {"range": range}
        s = "[j for i in range(100) if i > 10 for j in range(i) if j < 20]"
        self.t(s, eval(s))

    def test_triple_generators(self):
        self.s.functions = {"range": range}
        s = "[(a,b,c) for a in range(4) for b in range(a) for c in range(b)]"
        self.t(s, eval(s))

    def test_too_long_generator(self):
        self.s.functions = {"range": range}
        s = "[j for i in range(1000) if i > 10 for j in range(i) if j < 20]"
        with self.assertRaises(simpleeval.IterableTooLong):
            self.s.eval(s)

    def test_too_long_generator_2(self):
        self.s.functions = {"range": range}
        s = "[j for i in range(100) if i > 1 for j in range(i+10) if j < 100 for k in range(i*j)]"
        with self.assertRaises(simpleeval.IterableTooLong):
            self.s.eval(s)

    def test_nesting_generators_to_cheat(self):
        self.s.functions = {"range": range}
        s = "[[[c for c in range(a)] for a in range(b)] for b in range(200)]"

        with self.assertRaises(simpleeval.IterableTooLong):
            self.s.eval(s)

    def test_no_leaking_names(self):
        # see issue #52, failing list comprehensions could leak locals
        with self.assertRaises(simpleeval.NameNotDefined):
            self.s.eval('[x if x == "2" else y for x in "123"]')

        with self.assertRaises(simpleeval.NameNotDefined):
            self.s.eval("x")


class TestNames(DRYTest):
    """'names', what other languages call variables..."""

    def test_none(self):
        """what to do when names isn't defined, or is 'none'"""
        with self.assertRaises(NameNotDefined):
            self.t("a == 2", None)

        self.s.names["s"] = 21

        # or if you attempt to assign an unknown name to another
        with self.assertRaises(NameNotDefined):
            with warnings.catch_warnings(record=True) as ws:
                warnings.simplefilter("always")
                self.t("s += a", 21)
        self.assertIsInstance(ws[0].message, simpleeval.AssignmentAttempted)

        self.s.names = None

        with self.assertRaises(InvalidExpression):
            self.t("s", 21)

        self.s.names = {"a": {"b": {"c": 42}}}

        with self.assertRaises(AttributeDoesNotExist):
            self.t("a.b.d**2", 42)

    def test_dict(self):
        """using a normal dict for names lookup"""

        self.s.names = {"a": 42}
        self.t("a + a", 84)

        self.s.names["also"] = 100

        self.t("a + also - a", 100)

        # however, you can't assign to those names:
        with warnings.catch_warnings(record=True) as ws:
            warnings.simplefilter("always")
            self.t("a = 200", 200)
        self.assertIsInstance(ws[0].message, simpleeval.AssignmentAttempted)

        self.assertEqual(self.s.names["a"], 42)

        # or assign to lists

        self.s.names["b"] = [0]

        with warnings.catch_warnings(record=True) as ws:
            warnings.simplefilter("always")
            self.t("b[0] = 11", 11)
        self.assertIsInstance(ws[0].message, simpleeval.AssignmentAttempted)

        self.assertEqual(self.s.names["b"], [0])

        # but you can get items from a list:

        self.s.names["b"] = [6, 7]

        self.t("b[0] * b[1]", 42)

        # or from a dict

        self.s.names["c"] = {"i": 11}

        self.t("c['i']", 11)
        self.t("c.get('i')", 11)
        self.t("c.get('j', 11)", 11)
        self.t("c.get('j')", None)

        # you still can't assign though:

        with warnings.catch_warnings(record=True) as ws:
            warnings.simplefilter("always")
            self.t("c['b'] = 99", 99)
        self.assertIsInstance(ws[0].message, simpleeval.AssignmentAttempted)

        self.assertFalse("b" in self.s.names["c"])

        # and going all 'inception' on it doesn't work either:

        self.s.names["c"]["c"] = {"c": 11}

        with warnings.catch_warnings(record=True) as ws:
            warnings.simplefilter("always")
            self.t("c['c']['c'] = 21", 21)
        self.assertIsInstance(ws[0].message, simpleeval.AssignmentAttempted)

        self.assertEqual(self.s.names["c"]["c"]["c"], 11)

    def test_dict_attr_access(self):
        # nested dict

        self.assertEqual(self.s.ATTR_INDEX_FALLBACK, True)

        self.s.names = {"a": {"b": {"c": 42}}}

        self.t("a.b.c*2", 84)

        with warnings.catch_warnings(record=True) as ws:
            warnings.simplefilter("always")
            self.t("a.b.c = 11", 11)
        self.assertIsInstance(ws[0].message, simpleeval.AssignmentAttempted)

        self.assertEqual(self.s.names["a"]["b"]["c"], 42)

        # TODO: Wat?
        with warnings.catch_warnings(record=True) as ws:
            warnings.simplefilter("always")
            self.t("a.d = 11", 11)

        with self.assertRaises(KeyError):
            self.assertEqual(self.s.names["a"]["d"], 11)

    def test_dict_attr_access_disabled(self):
        # nested dict

        self.s.ATTR_INDEX_FALLBACK = False
        self.assertEqual(self.s.ATTR_INDEX_FALLBACK, False)

        self.s.names = {"a": {"b": {"c": 42}}}

        with self.assertRaises(simpleeval.AttributeDoesNotExist):
            self.t("a.b.c * 2", 84)

        self.t("a['b']['c'] * 2", 84)

        self.assertEqual(self.s.names["a"]["b"]["c"], 42)

    def test_object(self):
        """using an object for name lookup"""
        # pylint: disable=attribute-defined-outside-init

        class TestObject(object):
            @staticmethod
            def method_thing():
                return 42

        o = TestObject()
        o.a = 23
        o.b = 42
        o.c = TestObject()
        o.c.d = 9001

        self.s.names = {"o": o}

        self.t("o", o)
        self.t("o.a", 23)
        self.t("o.b + o.c.d", 9043)

        self.t("o.method_thing()", 42)

        with self.assertRaises(AttributeDoesNotExist):
            self.t("o.d", None)

    def test_func(self):
        """using a function for 'names lookup'"""

        def resolver(_):
            """all names now equal 1024!"""
            return 1024

        self.s.names = resolver

        self.t("a", 1024)
        self.t("a + b - c - d", 0)

        # the function can do stuff with the value it's sent:

        def my_name(node):
            """all names equal their textual name, twice."""
            return node.id + node.id

        self.s.names = my_name

        self.t("a", "aa")

    def test_from_doc(self):
        """the 'name first letter as value' example from the docs"""

        def name_handler(node):
            """return the alphabet number of the first letter of
            the name's textual name"""
            return ord(node.id[0].lower()) - 96

        self.s.names = name_handler
        self.t("a", 1)
        self.t("a + b", 3)

    def test_name_handler_name_not_found(self):
        def name_handler(node):
            if node.id[0] == "a":
                return 21
            raise NameNotDefined(node.id[0], "not found")

        self.s.names = name_handler
        self.s.functions = {"b": lambda: 100}
        self.t("a + a", 42)

        self.t("b()", 100)

        with self.assertRaises(NameNotDefined):
            self.t("c", None)

    def test_name_handler_raises_error(self):
        # What happens if our name-handler raises a different kind of error?
        # we want it to ripple up all the way...

        def name_handler(_node):
            return {}["test"]

        self.s.names = name_handler

        # This should never be accessed:
        self.s.functions = {"c": 42}

        with self.assertRaises(KeyError):
            self.t("c", None)


class TestWhitespace(DRYTest):
    """test that incorrect whitespace (preceding/trailing) doesn't matter."""

    def test_no_whitespace(self):
        self.t("200 + 200", 400)

    def test_trailing(self):
        self.t("200 + 200       ", 400)

    def test_preceding_whitespace(self):
        self.t("    200 + 200", 400)

    def test_preceding_tab_whitespace(self):
        self.t("\t200 + 200", 400)

    def test_preceding_mixed_whitespace(self):
        self.t("  \t 200 + 200", 400)

    def test_both_ends_whitespace(self):
        self.t("  \t 200 + 200  ", 400)


class TestSimpleEval(unittest.TestCase):
    """test the 'simple_eval' wrapper function"""

    def test_basic_run(self):
        self.assertEqual(simple_eval("6*7"), 42)

    def test_default_functions(self):
        self.assertEqual(simple_eval("rand() < 1.0 and rand() > -0.01"), True)
        self.assertEqual(simple_eval("randint(200) < 200 and rand() > 0"), True)


class TestMethodChaining(unittest.TestCase):
    def test_chaining_correct(self):
        """
        Contributed by Khalid Grandi (xaled).
        """

        class A(object):
            def __init__(self):
                self.a = "0"

            def add(self, b):
                self.a += "-add" + str(b)
                return self

            def sub(self, b):
                self.a += "-sub" + str(b)
                return self

            def tostring(self):
                return str(self.a)

        x = A()
        self.assertEqual(
            simple_eval("x.add(1).sub(2).sub(3).tostring()", names={"x": x}), "0-add1-sub2-sub3"
        )


class TestExtendingClass(unittest.TestCase):
    """
    It should be pretty easy to extend / inherit from the SimpleEval class,
    to further lock things down, or unlock stuff, or whatever.
    """

    def test_methods_forbidden(self):
        # Example from README
        class EvalNoMethods(simpleeval.SimpleEval):
            def _eval_call(self, node):
                if isinstance(node.func, ast.Attribute):
                    raise simpleeval.FeatureNotAvailable("No methods please, we're British")
                return super(EvalNoMethods, self)._eval_call(node)

        e = EvalNoMethods()

        self.assertEqual(e.eval('"stuff happens"'), "stuff happens")
        self.assertEqual(e.eval("22 + 20"), 42)
        self.assertEqual(e.eval('int("42")'), 42)

        with self.assertRaises(simpleeval.FeatureNotAvailable):
            e.eval('"  blah  ".strip()')


class TestExceptions(unittest.TestCase):
    """
    confirm a few attributes exist properly and haven't been
    eaten by 2to3 or whatever... (see #41)
    """

    def test_functionnotdefined(self):
        try:
            raise FunctionNotDefined("foo", "foo in bar")
        except FunctionNotDefined as e:
            assert hasattr(e, "func_name")
            assert getattr(e, "func_name") == "foo"
            assert hasattr(e, "expression")
            assert getattr(e, "expression") == "foo in bar"

    def test_namenotdefined(self):
        try:
            raise NameNotDefined("foo", "foo in bar")
        except NameNotDefined as e:
            assert hasattr(e, "name")
            assert getattr(e, "name") == "foo"
            assert hasattr(e, "expression")
            assert getattr(e, "expression") == "foo in bar"

    def test_attributedoesnotexist(self):
        try:
            raise AttributeDoesNotExist("foo", "foo in bar")
        except AttributeDoesNotExist as e:
            assert hasattr(e, "attr")
            assert getattr(e, "attr") == "foo"
            assert hasattr(e, "expression")
            assert getattr(e, "expression") == "foo in bar"


class TestUnusualComparisons(DRYTest):
    def test_custom_comparison_returner(self):
        class Blah(object):
            def __gt__(self, other):
                return self

        b = Blah()
        self.s.names = {"b": b}
        self.t("b > 2", b)

    def test_custom_comparison_doesnt_return_boolable(self):
        """
        SqlAlchemy, bless it's cotton socks, returns BinaryExpression objects
        when asking for comparisons between things.  These BinaryExpressions
        raise a TypeError if you try and check for Truthyiness.
        """

        class BinaryExpression(object):
            def __init__(self, value):
                self.value = value

            def __eq__(self, other):
                return self.value == getattr(other, "value", other)

            def __repr__(self):  # pragma: no cover
                return "<BinaryExpression:{}>".format(self.value)

            def __bool__(self):  # pragma: no cover
                # This is the only important part, to match SqlAlchemy - the rest
                # of the methods are just to make testing a bit easier...
                raise TypeError("Boolean value of this clause is not defined")

        class Blah(object):
            def __gt__(self, other):
                return BinaryExpression("GT")

            def __lt__(self, other):
                return BinaryExpression("LT")

        b = Blah()
        # These should not crash:
        self.assertEqual(b > 2, BinaryExpression("GT"))
        self.assertEqual(b < 2, BinaryExpression("LT"))

        # And should also work in simpleeval
        self.s.names = {"b": b}
        self.t("b > 2", BinaryExpression("GT"))
        self.t("1 < 5 > b", BinaryExpression("LT"))


class TestGetItemUnhappy(DRYTest):
    # Again, SqlAlchemy doing unusual things.  Throwing it's own errors, rather than
    # expected types...

    def test_getitem_not_implemented(self):
        class Meh(object):
            def __getitem__(self, key):
                raise NotImplementedError("booya!")

            def __getattr__(self, key):
                return 42

        m = Meh()

        self.assertEqual(m.anything, 42)
        with self.assertRaises(NotImplementedError):
            m["nothing"]  # pylint: disable=pointless-statement

        self.s.names = {"m": m}
        self.t("m.anything", 42)

        with self.assertRaises(NotImplementedError):
            self.t("m['nothing']", None)

        self.s.ATTR_INDEX_FALLBACK = False

        self.t("m.anything", 42)

        with self.assertRaises(NotImplementedError):
            self.t("m['nothing']", None)


class TestShortCircuiting(DRYTest):
    def test_shortcircuit_if(self):
        x = []

        def foo(y):
            x.append(y)
            return y

        self.s.functions = {"foo": foo}
        self.t("foo(1) if foo(2) else foo(3)", 1)
        self.assertListEqual(x, [2, 1])

        x = []
        self.t("42 if True else foo(99)", 42)
        self.assertListEqual(x, [])

    def test_shortcircuit_comparison(self):
        x = []

        def foo(y):
            x.append(y)
            return y

        self.s.functions = {"foo": foo}
        self.t("foo(11) < 12", True)
        self.assertListEqual(x, [11])
        x = []

        self.t("1 > 2 < foo(22)", False)
        self.assertListEqual(x, [])


class TestDisallowedFunctions(DRYTest):
    def test_functions_in_disallowed_functions_list(self):
        # a bit of double-entry testing. probably pointless.
        assert simpleeval.DISALLOW_FUNCTIONS.issuperset(
            {
                type,
                isinstance,
                eval,
                getattr,
                setattr,
                help,
                repr,
                compile,
                open,
                exec,
                os.popen,
                os.system,
            }
        )

    def test_functions_are_disallowed_at_init(self):
        for dangerous_function in simpleeval.DISALLOW_FUNCTIONS:
            with self.assertRaises(FeatureNotAvailable):
                SimpleEval(functions={"foo": dangerous_function})

    def test_functions_are_disallowed_in_expressions(self):
        for dangerous_function in simpleeval.DISALLOW_FUNCTIONS:
            with self.assertRaises(FeatureNotAvailable):
                s = SimpleEval()
                s.functions["foo"] = dangerous_function
                s.eval("foo(42)")

    def test_breakout_via_generator(self):
        # Thanks decorator-factory
        class Foo:
            def bar(self):
                yield "Hello, world!"

        # Test the generator does work - also adds the `yield` to codecov...
        assert list(Foo().bar()) == ["Hello, world!"]

        evil = "foo.bar().gi_frame.f_globals['__builtins__'].exec('raise RuntimeError(\"Oh no\")')"

        with self.assertRaises(FeatureNotAvailable):
            simple_eval(evil, names={"foo": Foo()})


@unittest.skipIf(platform.python_implementation() == "PyPy", "GC set_debug not available in PyPy")
class TestReferenceCleanup(DRYTest):
    """Test cleanup without cyclic references"""

    # pylint: disable=attribute-defined-outside-init

    def setUp(self):
        self._initial_gc_isenabled = gc.isenabled()

        gc.disable()
        gc.set_debug(gc.DEBUG_SAVEALL)

        gc.collect()
        self._initial_garbage_len = len(gc.garbage)

    def tearDown(self):
        gc.collect()
        self._final_garbage_len = len(gc.garbage)

        if self._initial_gc_isenabled:
            gc.enable()

        self.assertEqual(self._initial_garbage_len, self._final_garbage_len)

    def test_simpleeval_cleanup(self):
        simpleeval.SimpleEval()


class TestNoEntries(DRYTest):
    def test_no_functions(self):
        self.s.eval("int(42)")
        with self.assertRaises(FunctionNotDefined):
            s = SimpleEval(functions={})
            s.eval("int(42)")

    def test_no_names(self):
        # does not work on current Py3, True et al. are keywords now
        self.s.eval("True")
        # with self.assertRaises(NameNotDefined):
        s = SimpleEval(names={})
        if sys.version_info < (3,):
            with self.assertRaises(NameNotDefined):
                s.eval("True")
        else:
            s.eval("True")

    def test_no_operators(self):
        self.s.eval("1+2")
        self.s.eval("~2")
        s = SimpleEval(operators={})

        with self.assertRaises(OperatorNotDefined):
            s.eval("1+2")

        with self.assertRaises(OperatorNotDefined):
            s.eval("~ 2")


class TestAllowedAttributes(DRYTest):
    def setUp(self):
        self.saved_disallow_methods = simpleeval.DISALLOW_METHODS
        simpleeval.DISALLOW_METHODS = []
        super().setUp()

    def tearDown(self) -> None:
        simpleeval.DISALLOW_METHODS = self.saved_disallow_methods
        return super().tearDown()

    def test_allowed_attrs_(self):
        self.s.allowed_attrs = BASIC_ALLOWED_ATTRS
        self.t("5 + 5", 10)
        self.t('"   hello  ".strip()', "hello")

    def test_allowed_extra_attr(self):
        class Foo:
            def bar(self):
                return 42

        assert Foo().bar() == 42

        extended_attrs = BASIC_ALLOWED_ATTRS.copy()
        extended_attrs[Foo] = {"bar"}

        simple_eval("foo.bar()", names={"foo": Foo()}, allowed_attrs=extended_attrs)

    def test_disallowed_extra_attr(self):
        class Foo:
            bar = 42
            hidden = 100

        assert Foo().bar == 42

        extended_attrs = BASIC_ALLOWED_ATTRS.copy()
        extended_attrs[Foo] = {"bar"}

        self.assertEqual(
            simple_eval("foo.bar", names={"foo": Foo()}, allowed_attrs=extended_attrs), 42
        )
        with self.assertRaisesRegex(FeatureNotAvailable, r".*'\.hidden' access not allowed.*"):
            self.assertEqual(
                simple_eval("foo.hidden", names={"foo": Foo()}, allowed_attrs=extended_attrs), 42
            )

    def test_disallowed_types(self):
        class Foo:
            bar = 42

        assert Foo().bar == 42

        with self.assertRaises(FeatureNotAvailable):
            simple_eval("foo.bar", names={"foo": Foo()}, allowed_attrs=BASIC_ALLOWED_ATTRS)

    def test_breakout_via_generator(self):
        # Thanks decorator-factory
        class Foo:
            def bar(self):
                yield "Hello, world!"

        # Test the generator does work - also adds the `yield` to codecov...
        assert list(Foo().bar()) == ["Hello, world!"]

        evil = "foo.bar().gi_frame.f_globals['__builtins__'].exec('raise RuntimeError(\"Oh no\")')"

        extended_attrs = BASIC_ALLOWED_ATTRS.copy()
        extended_attrs[Foo] = {"bar"}

        with self.assertRaisesRegex(FeatureNotAvailable, r".*attempted to access `\.gi_frame`.*"):
            simple_eval(evil, names={"foo": Foo()}, allowed_attrs=extended_attrs)


if __name__ == "__main__":  # pragma: no cover
    unittest.main()