deb-python-testtools/testtools/tests/matchers/test_exception.py

# Copyright (c) 2008-2012 testtools developers. See LICENSE for details.

import sys

from testtools import TestCase
from testtools.matchers import (
    AfterPreprocessing,
    Equals,
    )
from testtools.matchers._exception import (
    MatchesException,
    Raises,
    raises,
    )
from testtools.tests.helpers import FullStackRunTest
from testtools.tests.matchers.helpers import TestMatchersInterface


def make_error(type, *args, **kwargs):
    try:
        raise type(*args, **kwargs)
    except type:
        return sys.exc_info()


class TestMatchesExceptionInstanceInterface(TestCase, TestMatchersInterface):

    matches_matcher = MatchesException(ValueError("foo"))
    error_foo = make_error(ValueError, 'foo')
    error_bar = make_error(ValueError, 'bar')
    error_base_foo = make_error(Exception, 'foo')
    matches_matches = [error_foo]
    matches_mismatches = [error_bar, error_base_foo]

    str_examples = [
        ("MatchesException(Exception('foo',))",
         MatchesException(Exception('foo')))
        ]
    describe_examples = [
        ("%r is not a %r" % (Exception, ValueError),
         error_base_foo,
         MatchesException(ValueError("foo"))),
        ("ValueError('bar',) has different arguments to ValueError('foo',).",
         error_bar,
         MatchesException(ValueError("foo"))),
        ]


class TestMatchesExceptionTypeInterface(TestCase, TestMatchersInterface):

    matches_matcher = MatchesException(ValueError)
    error_foo = make_error(ValueError, 'foo')
    error_sub = make_error(UnicodeError, 'bar')
    error_base_foo = make_error(Exception, 'foo')
    matches_matches = [error_foo, error_sub]
    matches_mismatches = [error_base_foo]

    str_examples = [
        ("MatchesException(%r)" % Exception,
         MatchesException(Exception))
        ]
    describe_examples = [
        ("%r is not a %r" % (Exception, ValueError),
         error_base_foo,
         MatchesException(ValueError)),
        ]


class TestMatchesExceptionTypeReInterface(TestCase, TestMatchersInterface):

    matches_matcher = MatchesException(ValueError, 'fo.')
    error_foo = make_error(ValueError, 'foo')
    error_sub = make_error(UnicodeError, 'foo')
    error_bar = make_error(ValueError, 'bar')
    matches_matches = [error_foo, error_sub]
    matches_mismatches = [error_bar]

    str_examples = [
        ("MatchesException(%r)" % Exception,
         MatchesException(Exception, 'fo.'))
        ]
    describe_examples = [
        ("'bar' does not match /fo./",
         error_bar, MatchesException(ValueError, "fo.")),
        ]


class TestMatchesExceptionTypeMatcherInterface(TestCase, TestMatchersInterface):

    matches_matcher = MatchesException(
        ValueError, AfterPreprocessing(str, Equals('foo')))
    error_foo = make_error(ValueError, 'foo')
    error_sub = make_error(UnicodeError, 'foo')
    error_bar = make_error(ValueError, 'bar')
    matches_matches = [error_foo, error_sub]
    matches_mismatches = [error_bar]

    str_examples = [
        ("MatchesException(%r)" % Exception,
         MatchesException(Exception, Equals('foo')))
        ]
    describe_examples = [
        ("%r != 5" % (error_bar[1],),
         error_bar, MatchesException(ValueError, Equals(5))),
        ]


class TestRaisesInterface(TestCase, TestMatchersInterface):

    matches_matcher = Raises()
    def boom():
        raise Exception('foo')
    matches_matches = [boom]
    matches_mismatches = [lambda:None]

    # Tricky to get function objects to render constantly, and the interfaces
    # helper uses assertEqual rather than (for instance) DocTestMatches.
    str_examples = []

    describe_examples = []


class TestRaisesExceptionMatcherInterface(TestCase, TestMatchersInterface):

    matches_matcher = Raises(
        exception_matcher=MatchesException(Exception('foo')))
    def boom_bar():
        raise Exception('bar')
    def boom_foo():
        raise Exception('foo')
    matches_matches = [boom_foo]
    matches_mismatches = [lambda:None, boom_bar]

    # Tricky to get function objects to render constantly, and the interfaces
    # helper uses assertEqual rather than (for instance) DocTestMatches.
    str_examples = []

    describe_examples = []


class TestRaisesBaseTypes(TestCase):

    run_tests_with = FullStackRunTest

    def raiser(self):
        raise KeyboardInterrupt('foo')

    def test_KeyboardInterrupt_matched(self):
        # When KeyboardInterrupt is matched, it is swallowed.
        matcher = Raises(MatchesException(KeyboardInterrupt))
        self.assertThat(self.raiser, matcher)

    def test_KeyboardInterrupt_propagates(self):
        # The default 'it raised' propagates KeyboardInterrupt.
        match_keyb = Raises(MatchesException(KeyboardInterrupt))
        def raise_keyb_from_match():
            matcher = Raises()
            matcher.match(self.raiser)
        self.assertThat(raise_keyb_from_match, match_keyb)

    def test_KeyboardInterrupt_match_Exception_propagates(self):
        # If the raised exception isn't matched, and it is not a subclass of
        # Exception, it is propagated.
        match_keyb = Raises(MatchesException(KeyboardInterrupt))
        def raise_keyb_from_match():
            matcher = Raises(MatchesException(Exception))
            matcher.match(self.raiser)
        self.assertThat(raise_keyb_from_match, match_keyb)


class TestRaisesConvenience(TestCase):

    run_tests_with = FullStackRunTest

    def test_exc_type(self):
        self.assertThat(lambda: 1/0, raises(ZeroDivisionError))

    def test_exc_value(self):
        e = RuntimeError("You lose!")
        def raiser():
            raise e
        self.assertThat(raiser, raises(e))


def test_suite():
    from unittest import TestLoader
    return TestLoader().loadTestsFromName(__name__)