Module pedantic.tests.test_context_manager

Classes

class TestContextManager (methodName='runTest')

A class whose instances are single test cases.

By default, the test code itself should be placed in a method named 'runTest'.

If the fixture may be used for many test cases, create as many test methods as are needed. When instantiating such a TestCase subclass, specify in the constructor arguments the name of the test method that the instance is to execute.

Test authors should subclass TestCase for their own tests. Construction and deconstruction of the test's environment ('fixture') can be implemented by overriding the 'setUp' and 'tearDown' methods respectively.

If it is necessary to override the init method, the base class init method must always be called. It is important that subclasses should not change the signature of their init method, since instances of the classes are instantiated automatically by parts of the framework in order to be run.

When subclassing TestCase, you can set these attributes: * failureException: determines which exception will be raised when the instance's assertion methods fail; test methods raising this exception will be deemed to have 'failed' rather than 'errored'. * longMessage: determines whether long messages (including repr of objects used in assert methods) will be printed on failure in addition to any explicit message passed. * maxDiff: sets the maximum length of a diff in failure messages by assert methods using difflib. It is looked up as an instance attribute so can be configured by individual tests if required.

Create an instance of the class that will use the named test method when executed. Raises a ValueError if the instance does not have a method with the specified name.

Expand source code

class TestContextManager(TestCase):
    def test_safe_context_manager_no_exception(self):
        before = False
        after = False

        @safe_contextmanager
        def foo():
            nonlocal before, after
            before = True
            yield 42
            after = True

        self.assertFalse(before)
        self.assertFalse(after)

        with foo() as f:
            self.assertTrue(before)
            self.assertFalse(after)
            self.assertEqual(42, f)

        self.assertTrue(before)
        self.assertTrue(after)

    def test_safe_context_manager_with_exception(self):
        before = False
        after = False

        @safe_contextmanager
        def foo():
            nonlocal before, after
            before = True
            yield 42
            after = True

        self.assertFalse(before)
        self.assertFalse(after)

        with self.assertRaises(expected_exception=ValueError):
            with foo() as f:
                self.assertTrue(before)
                self.assertFalse(after)
                self.assertEqual(42, f)
                raise ValueError('oh no')

        self.assertTrue(before)
        self.assertTrue(after)

    def test_safe_context_manager_with_args_kwargs(self):
        @safe_contextmanager
        def foo(a, b):
            yield a, b

        with foo(42, b=43) as f:
            self.assertEqual((42, 43), f)

    def test_safe_context_manager_async(self):
        with self.assertRaises(expected_exception=AssertionError) as e:
            @safe_contextmanager
            async def foo(a, b):
                yield a, b

        expected = 'foo is async. So you need to use "safe_async_contextmanager" instead.'
        self.assertEqual(expected, e.exception.args[0])

    def test_safe_context_manager_non_generator(self):
        with self.assertRaises(expected_exception=AssertionError) as e:
            @safe_contextmanager
            def foo(a, b):
                return a, b

        expected = 'foo is not a generator.'
        self.assertEqual(expected, e.exception.args[0])

Ancestors

• unittest.case.TestCase

Methods

def test_safe_context_manager_async(self)

Expand source code

def test_safe_context_manager_async(self):
    with self.assertRaises(expected_exception=AssertionError) as e:
        @safe_contextmanager
        async def foo(a, b):
            yield a, b

    expected = 'foo is async. So you need to use "safe_async_contextmanager" instead.'
    self.assertEqual(expected, e.exception.args[0])

def test_safe_context_manager_no_exception(self)

Expand source code

def test_safe_context_manager_no_exception(self):
    before = False
    after = False

    @safe_contextmanager
    def foo():
        nonlocal before, after
        before = True
        yield 42
        after = True

    self.assertFalse(before)
    self.assertFalse(after)

    with foo() as f:
        self.assertTrue(before)
        self.assertFalse(after)
        self.assertEqual(42, f)

    self.assertTrue(before)
    self.assertTrue(after)

def test_safe_context_manager_non_generator(self)

Expand source code

def test_safe_context_manager_non_generator(self):
    with self.assertRaises(expected_exception=AssertionError) as e:
        @safe_contextmanager
        def foo(a, b):
            return a, b

    expected = 'foo is not a generator.'
    self.assertEqual(expected, e.exception.args[0])

def test_safe_context_manager_with_args_kwargs(self)

Expand source code

def test_safe_context_manager_with_args_kwargs(self):
    @safe_contextmanager
    def foo(a, b):
        yield a, b

    with foo(42, b=43) as f:
        self.assertEqual((42, 43), f)

def test_safe_context_manager_with_exception(self)

Expand source code

def test_safe_context_manager_with_exception(self):
    before = False
    after = False

    @safe_contextmanager
    def foo():
        nonlocal before, after
        before = True
        yield 42
        after = True

    self.assertFalse(before)
    self.assertFalse(after)

    with self.assertRaises(expected_exception=ValueError):
        with foo() as f:
            self.assertTrue(before)
            self.assertFalse(after)
            self.assertEqual(42, f)
            raise ValueError('oh no')

    self.assertTrue(before)
    self.assertTrue(after)