pytest2/testing/python/raises.py

from _pytest.outcomes import Failed
import pytest
import sys


class TestRaises(object):
    def test_raises(self):
        source = "int('qwe')"
        excinfo = pytest.raises(ValueError, source)
        code = excinfo.traceback[-1].frame.code
        s = str(code.fullsource)
        assert s == source

    def test_raises_exec(self):
        pytest.raises(ValueError, "a,x = []")

    def test_raises_syntax_error(self):
        pytest.raises(SyntaxError, "qwe qwe qwe")

    def test_raises_function(self):
        pytest.raises(ValueError, int, "hello")

    def test_raises_callable_no_exception(self):
        class A(object):
            def __call__(self):
                pass

        try:
            pytest.raises(ValueError, A())
        except pytest.raises.Exception:
            pass

    def test_raises_as_contextmanager(self, testdir):
        testdir.makepyfile(
            """
            import pytest
            import _pytest._code

            def test_simple():
                with pytest.raises(ZeroDivisionError) as excinfo:
                    assert isinstance(excinfo, _pytest._code.ExceptionInfo)
                    1/0
                print (excinfo)
                assert excinfo.type == ZeroDivisionError
                assert isinstance(excinfo.value, ZeroDivisionError)

            def test_noraise():
                with pytest.raises(pytest.raises.Exception):
                    with pytest.raises(ValueError):
                           int()

            def test_raise_wrong_exception_passes_by():
                with pytest.raises(ZeroDivisionError):
                    with pytest.raises(ValueError):
                           1/0
        """
        )
        result = testdir.runpytest()
        result.stdout.fnmatch_lines(["*3 passed*"])

    def test_noclass(self):
        with pytest.raises(TypeError):
            pytest.raises("wrong", lambda: None)

    def test_invalid_arguments_to_raises(self):
        with pytest.raises(TypeError, match="unknown"):
            with pytest.raises(TypeError, unknown="bogus"):
                raise ValueError()

    def test_tuple(self):
        with pytest.raises((KeyError, ValueError)):
            raise KeyError("oops")

    def test_no_raise_message(self):
        try:
            pytest.raises(ValueError, int, "0")
        except pytest.raises.Exception as e:
            assert e.msg == "DID NOT RAISE {}".format(repr(ValueError))
        else:
            assert False, "Expected pytest.raises.Exception"

        try:
            with pytest.raises(ValueError):
                pass
        except pytest.raises.Exception as e:
            assert e.msg == "DID NOT RAISE {}".format(repr(ValueError))
        else:
            assert False, "Expected pytest.raises.Exception"

    def test_custom_raise_message(self):
        message = "TEST_MESSAGE"
        try:
            with pytest.raises(ValueError, message=message):
                pass
        except pytest.raises.Exception as e:
            assert e.msg == message
        else:
            assert False, "Expected pytest.raises.Exception"

    @pytest.mark.parametrize("method", ["function", "with"])
    def test_raises_cyclic_reference(self, method):
        """
        Ensure pytest.raises does not leave a reference cycle (#1965).
        """
        import gc

        class T(object):
            def __call__(self):
                raise ValueError

        t = T()
        if method == "function":
            pytest.raises(ValueError, t)
        else:
            with pytest.raises(ValueError):
                t()

        # ensure both forms of pytest.raises don't leave exceptions in sys.exc_info()
        assert sys.exc_info() == (None, None, None)

        del t

        # ensure the t instance is not stuck in a cyclic reference
        for o in gc.get_objects():
            assert type(o) is not T

    def test_raises_match(self):
        msg = r"with base \d+"
        with pytest.raises(ValueError, match=msg):
            int("asdf")

        msg = "with base 10"
        with pytest.raises(ValueError, match=msg):
            int("asdf")

        msg = "with base 16"
        expr = r"Pattern '{}' not found in 'invalid literal for int\(\) with base 10: 'asdf''".format(
            msg
        )
        with pytest.raises(AssertionError, match=expr):
            with pytest.raises(ValueError, match=msg):
                int("asdf", base=10)

    def test_raises_match_wrong_type(self):
        """Raising an exception with the wrong type and match= given.

        pytest should throw the unexpected exception - the pattern match is not
        really relevant if we got a different exception.
        """
        with pytest.raises(ValueError):
            with pytest.raises(IndexError, match="nomatch"):
                int("asdf")

    def test_raises_exception_looks_iterable(self):
        from six import add_metaclass

        class Meta(type(object)):
            def __getitem__(self, item):
                return 1 / 0

            def __len__(self):
                return 1

        @add_metaclass(Meta)
        class ClassLooksIterableException(Exception):
            pass

        with pytest.raises(
            Failed, match="DID NOT RAISE <class 'raises.ClassLooksIterableException'>"
        ):
            pytest.raises(ClassLooksIterableException, lambda: None)