docs/integrations.rst
Integrations
============
``grappa`` is library/framework agnostic, so you can use it with your preferred
testing framework, such as `nose`, `pytest`, `behave`...
This page provides some useful information and configuration tips
for a better and more friendly integration between ``grappa`` and
testing framework.
pytest
------
Friendly error traceback
^^^^^^^^^^^^^^^^^^^^^^^^
``pytest``, by default, provides a custom error reporting based on the traceback
analysis, pretty much as ``grappa`` does, but unfortunately in a less friendly way
for the developer.
You can partially or completely disable this in ``pytest`` behavior in order to have
more friendly errors generated by ``grappa``.
In order to do that you should simply pass the following flag to:
.. code-block:: bash
$ pytest --tb=native
Or alternatively, you can simply partially disable it:
.. code-block:: bash
$ pytest --tb=short
The difference would be from this:
.. code-block:: bash
________________ test_expect_context_manager ________________
tests/should_test.py:277: in test_expect_context_manager
should('foo').be.equal('bar')
grappa/assertion.py:16: in __call__
return self._fn(expected, *args, **kw)
grappa/resolver.py:60: in wrapper
return self.test._trigger()
grappa/test.py:145: in _trigger
raise err
E AssertionError: Oops! Something went wrong!
E
E The following assertion was not satisfied
E subject "foo" should be equal "bar"
E
E What we expected
E a value that is equal to "foo"
E
E What we got instead
E an value of type "str" with data "foo"
E
E Where
E File "tests/should_test.py", line 277, in test_expect_context_manager
E
E 269| with pytest.raises(AssertionError):
E 270| 10 | should.not_be.between.to(5, 10)
E 271|
E 272| with pytest.raises(AssertionError):
E 273| None | should.be.between.numbers(10, 10)
E 274|
E 275|
E 276| def test_expect_context_manager():
E 277| > should('foo').be.equal('bar')
E 278|
E 279| with should('foo'):
E 280| should.be.equal('foo')
E 281| should.have.length.of(3)
E 282| should.have.type('string')
E 283|
E 284| with should('foo'):
Into this:
.. code-block:: bash
Traceback (most recent call last):
File "tests/should_test.py", line 277, in test_expect_context_manager
should('foo').be.equal('bar')
File "grappa/assertion.py", line 16, in __call__
return self._fn(expected, *args, **kw)
File "grappa/resolver.py", line 60, in wrapper
return self.test._trigger()
File "grappa/test.py", line 145, in _trigger
raise err
AssertionError: Oops! Something went wrong!
The following assertion was not satisfied
subject "foo" should be equal "bar"
What we expected
a value that is equal to "foo"
What we got instead
an value of type "str" with data "foo"
Where
File "tests/should_test.py", line 277, in test_expect_context_manager
269| with pytest.raises(AssertionError):
270| 10 | should.not_be.between.to(5, 10)
271|
272| with pytest.raises(AssertionError):
273| None | should.be.between.numbers(10, 10)
274|
275|
276| def test_expect_context_manager():
277| > should('foo').be.equal('bar')
278|
279| with should('foo'):
280| should.be.equal('foo')
281| should.have.length.of(3)
282| should.have.type('string')
283|
284| with should('foo'):
Dependency injection using fixtures
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
In order to minimize boilerplate across tests, you can create a ``pytest`` fixture
that would be automatically injected via across test functions/methods in your test suites:
First, create a ``conftest.py`` file in the directory where your test files lives with the following content:
.. code-block:: python
# tests/conftest.py
import pytest
from grappa import should as _should, expect as _expect
@pytest.fixture
def should():
return _should
@pytest.fixture
def expect():
return _expect
Then, from a test file module, you can simply declare a test function that accepts a fixture argument, such as:
.. code-block:: python
# tests/sample_test.py
def test_should_fixture(should):
'foo' | should.have.length.of(3) | should.be.equal.to('foo')
def test_expect_fixture(expect):
'foo' | expect.to.have.length.of(3) | expect.to.be.equal.to('foo')