diff --git a/doc/en/assert.rst b/doc/en/assert.rst index 186e12853..b119adcf0 100644 --- a/doc/en/assert.rst +++ b/doc/en/assert.rst @@ -88,23 +88,30 @@ and if you need to have access to the actual exception info you may use:: the actual exception raised. The main attributes of interest are ``.type``, ``.value`` and ``.traceback``. -.. versionchanged:: 3.0 +You can pass a ``match`` keyword parameter to the context-manager to test +that a regular expression matches on the string representation of an exception +(similar to the ``TestCase.assertRaisesRegexp`` method from ``unittest``):: -In the context manager form you may use the keyword argument -``message`` to specify a custom failure message:: + import pytest - >>> with raises(ZeroDivisionError, message="Expecting ZeroDivisionError"): - ... pass - ... Failed: Expecting ZeroDivisionError + def myfunc(): + raise ValueError("Exception 123 raised") -If you want to write test code that works on Python 2.4 as well, -you may also use two other ways to test for an expected exception:: + def test_match(): + with pytest.raises(ValueError, match=r'.* 123 .*'): + myfunc() + +The regexp parameter of the ``match`` method is matched with the ``re.search`` +function, so in the above example ``match='123'`` would have worked as +well. + +There's an alternate form of the ``pytest.raises`` function where you pass +a function that will be executed with the given ``*args`` and ``**kwargs`` and +assert that the given exception is raised:: pytest.raises(ExpectedException, func, *args, **kwargs) -which will execute the specified function with args and kwargs and -assert that the given ``ExpectedException`` is raised. The reporter will -provide you with helpful output in case of failures such as *no +The reporter will provide you with helpful output in case of failures such as *no exception* or *wrong exception*. Note that it is also possible to specify a "raises" argument to @@ -121,23 +128,6 @@ exceptions your own code is deliberately raising, whereas using like documenting unfixed bugs (where the test describes what "should" happen) or bugs in dependencies. -Also, the context manager form accepts a ``match`` keyword parameter to test -that a regular expression matches on the string representation of an exception -(like the ``TestCase.assertRaisesRegexp`` method from ``unittest``):: - - import pytest - - def myfunc(): - raise ValueError("Exception 123 raised") - - def test_match(): - with pytest.raises(ValueError, match=r'.* 123 .*'): - myfunc() - -The regexp parameter of the ``match`` method is matched with the ``re.search`` -function. So in the above example ``match='123'`` would have worked as -well. - .. _`assertwarns`: