From 773f8d92f15983d71908f8497747f043806ad828 Mon Sep 17 00:00:00 2001 From: Chronial Date: Wed, 27 Jan 2016 05:25:56 +0100 Subject: [PATCH] Wrap assert methods of mock module to clean up traceback --- README.rst | 8 ++++ pytest_mock.py | 96 +++++++++++++++++++++++++++++++++++++++++++++ test_pytest_mock.py | 91 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 195 insertions(+) diff --git a/README.rst b/README.rst index f7ac83f..d627ca0 100644 --- a/README.rst +++ b/README.rst @@ -143,6 +143,14 @@ module and the plugin were required within a test. The old fixture ``mock`` still works, but its use is discouraged and will be removed in version ``1.0``. +Improved reporting of mock call assertion errors +------------------------------------------------ + +This plugin monkeypatches the mock library to improve pytest output for failures +of mock call assertions like ``Mock.assert_called_with()``. This can be disabled +by setting ``mock_traceback_monkeypatch = false`` in the ini. + + Requirements ============ diff --git a/pytest_mock.py b/pytest_mock.py index 295171d..949bdf1 100644 --- a/pytest_mock.py +++ b/pytest_mock.py @@ -2,6 +2,7 @@ import sys import pytest +from distutils.util import strtobool if sys.version_info >= (3, 3): # pragma: no cover import unittest.mock as mock_module @@ -137,3 +138,98 @@ def mock(mocker): warnings.warn('"mock" fixture has been deprecated, use "mocker" instead', DeprecationWarning) return mocker + + +_mock_module_patches = [] +_mock_module_originals = {} + + +def assert_wrapper(method, *args, **kwargs): + __tracebackhide__ = True + try: + method(*args, **kwargs) + except AssertionError as e: + raise AssertionError(*e.args) + + +def wrap_assert_not_called(*args, **kwargs): + __tracebackhide__ = True + assert_wrapper(_mock_module_originals["assert_not_called"], + *args, **kwargs) + + +def wrap_assert_called_with(*args, **kwargs): + __tracebackhide__ = True + assert_wrapper(_mock_module_originals["assert_called_with"], + *args, **kwargs) + + +def wrap_assert_called_once_with(*args, **kwargs): + __tracebackhide__ = True + assert_wrapper(_mock_module_originals["assert_called_once_with"], + *args, **kwargs) + + +def wrap_assert_has_calls(*args, **kwargs): + __tracebackhide__ = True + assert_wrapper(_mock_module_originals["assert_has_calls"], + *args, **kwargs) + + +def wrap_assert_any_call(*args, **kwargs): + __tracebackhide__ = True + assert_wrapper(_mock_module_originals["assert_any_call"], + *args, **kwargs) + + +def wrap_assert_methods(config): + """ + Wrap assert methods of mock module so we can hide their traceback + """ + # Make sure we only do this once + if _mock_module_originals: + return + + wrappers = { + 'assert_not_called': wrap_assert_not_called, + 'assert_called_with': wrap_assert_called_with, + 'assert_called_once_with': wrap_assert_called_once_with, + 'assert_has_calls': wrap_assert_has_calls, + 'assert_any_call': wrap_assert_any_call, + } + for method, wrapper in wrappers.items(): + try: + original = getattr(mock_module.NonCallableMock, method) + except AttributeError: + continue + _mock_module_originals[method] = original + patcher = mock_module.patch.object( + mock_module.NonCallableMock, method, wrapper) + patcher.start() + _mock_module_patches.append(patcher) + config.add_cleanup(unwrap_assert_methods) + + +def unwrap_assert_methods(): + for patcher in _mock_module_patches: + patcher.stop() + _mock_module_patches[:] = [] + _mock_module_originals.clear() + + +def pytest_addoption(parser): + parser.addini('mock_traceback_monkeypatch', + 'Monkeypatch the mock library to improve reporting of the ' + 'assert_called_... methods', + default=True) + + +def parse_ini_boolean(value): + if value in (True, False): + return value + return bool(strtobool(value)) + + +def pytest_configure(config): + if parse_ini_boolean(config.getini('mock_traceback_monkeypatch')): + wrap_assert_methods(config) diff --git a/test_pytest_mock.py b/test_pytest_mock.py index 23868b8..d0516b2 100644 --- a/test_pytest_mock.py +++ b/test_pytest_mock.py @@ -1,6 +1,9 @@ import os import platform +import sys +from contextlib import contextmanager +import py.code import pytest @@ -246,3 +249,91 @@ def bar(arg): assert Foo.bar(arg=10) == 20 Foo.bar.assert_called_once_with(arg=10) spy.assert_called_once_with(arg=10) + + +@contextmanager +def assert_traceback(): + """ + Assert that this file is at the top of the filtered traceback + """ + try: + yield + except AssertionError: + traceback = py.code.ExceptionInfo().traceback + crashentry = traceback.getcrashentry() + assert crashentry.path == __file__ + else: + raise AssertionError("DID NOT RAISE") + + +@pytest.mark.skipif(sys.version_info[:2] == (3, 4), + reason="assert_not_called not available in python 3.4") +def test_assert_not_called_wrapper(mocker): + stub = mocker.stub() + stub.assert_not_called() + stub() + with assert_traceback(): + stub.assert_not_called() + + +def test_assert_called_with_wrapper(mocker): + stub = mocker.stub() + stub("foo") + stub.assert_called_with("foo") + with assert_traceback(): + stub.assert_called_with("bar") + + +def test_assert_called_once_with_wrapper(mocker): + stub = mocker.stub() + stub("foo") + stub.assert_called_once_with("foo") + stub("foo") + with assert_traceback(): + stub.assert_called_once_with("foo") + + +def test_assert_any_call_wrapper(mocker): + stub = mocker.stub() + stub("foo") + stub("foo") + stub.assert_any_call("foo") + with assert_traceback(): + stub.assert_any_call("bar") + + +def test_assert_has_calls(mocker): + from pytest_mock import mock_module + stub = mocker.stub() + stub("foo") + stub.assert_has_calls([mock_module.call("foo")]) + with assert_traceback(): + stub.assert_has_calls([mock_module.call("bar")]) + + +def test_monkeypatch_ini(mocker, testdir): + # Make sure the following function actually tests something + stub = mocker.stub() + assert stub.assert_called_with.__module__ != stub.__module__ + + testdir.makepyfile(""" + import py.code + def test_foo(mocker): + stub = mocker.stub() + assert stub.assert_called_with.__module__ == stub.__module__ + """) + testdir.makeini(""" + [pytest] + mock_traceback_monkeypatch = false + """) + + result = testdir.runpytest_subprocess() + assert result.ret == 0 + + +def test_parse_ini_boolean(testdir): + import pytest_mock + assert pytest_mock.parse_ini_boolean('True') is True + assert pytest_mock.parse_ini_boolean('false') is False + with pytest.raises(ValueError): + pytest_mock.parse_ini_boolean('foo')