.. image:: http://i.imgur.com/kKZPYut.jpg :width: 100% :alt: grappa logo :align: center
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grappa is a behavior-oriented, self-declarative, expressive and developer-friendly
lightweight assertion library for Python_ that aims to make testing more productive and frictionless for humans.
grappa comes with two declarative assertion styles_: expect and should.
It also comes with a detailed, human-friendly error reporting_ system that aims to reduce friction,
provide better feedback and improve human speed and agility while identifying and fixing errors.
To get started, take a look to the showcase_ code, tutorial, available plugins and operators documentation_.
For HTTP protocol assertions, see grappa-http_.
grappa is considered stable software, however it's not mature, widely used software.
New features may be added from time to time or minor bugs may be experienced.
Community contributions and bug reports are very welcome.
A small example demonstrating some grappa features.
See documentation_ and tutorial_ for more examples.
.. code-block:: python
from grappa import should
True | should.be.true
False | should.be.false
None | should.be.none
'' | should.be.empty
[] | should.be.empty
'foo' | should.exists
3.14 | should.be.lower.than(4)
3.14 | should.be.higher.than(3)
3.14 | should.be.within(2, 4)
'bar' | should.be.equal.to('bar', msg='value is not "bar"')
[1, 2, 3] | should.be.equal.to([1, 2, 3])
'hello, grappa' | should.startswith('hello')
'hello, grappa' | should.endswith('grappa')
[1, 2, 3, 4] | should.startswith(1)
[1, 2, 3, 4] | should.endswith(4)
'Hello grappa' | should.match('(\W)+ grappa$')
'Hello grappa' | should.contain('grappa') | should.contain('he')
['foo', 'bar'] | should.contain('foo') | should.do_not.contain('baz')
'foo' | should.be.a('string')
{'foo': True} | should.be.a('dict')
iter([1, 2, 3]) | should.have.length.of(3)
[1, 2, 3] | should.be.a('list') > should.have.length.of(3)
(lambda x: x) | should.be.callable
(lambda x: x) | should.not_have.type.of('generator')
'foo' | should.pass_test(lambda x: x in 'foo bar')
'foo' | should.pass_function(lambda x: len(x) > 2)
(lambda: x) | should.raises(NameError)
(lambda: x) | should.does_not.raises(RuntimeError)
{'foo': 'bar'} | should.have.key('foo').that.should.be.equal('bar')
(1, 2, 3, 4) | should.be.a(tuple) > should.have.index.at(3) > should.be.equal.to(4)
an_object | should.have.properties('foo', 'bar', 'baz')
an_object | should.implement.methods('foo', 'bar', 'baz')
{'foo': True, 'bar': False} | should.all(should.have.key('foo'), should.have.key('bar'))
{'foo': True, 'bar': False} | should.any(should.have.key('foo'), should.have.key('baz'))
({'bar': [1, 2, 3]}
| should.have.key('bar')
> should.be.a('list')
> should.have.length.of(3)
> should.contain.item(3)
> should.have.index.at(1)
> should.be.equal.to(2))
with should('foo'):
should.be.a(str)
should.have.length.of(3)
should.be.equal.to('foo')
Let's see how the error report looks like in grappa running in pytest.
See error reporting_ documentation for more details about how grappa error report system works.
.. code-block:: python
======================================================================
FAIL: tests.should_test.test_grappa_assert
======================================================================
Traceback (most recent call last):
File ".pyenv/versions/3.6.0/lib/python3.6/site-packages/nose/case.py", line 198, in runTest
self.test(*self.arg)
File "grappa/tests/should_test.py", line 16, in test_grappa_assert
x | should.be.have.length.of(4)
File "grappa/grappa/test.py", line 248, in __ror__
return self.__overload__(value)
File "grappa/grappa/test.py", line 236, in __overload__
return self.__call__(subject, overload=True)
File "grappa/grappa/test.py", line 108, in __call__
return self._trigger() if overload else Test(subject)
File "grappa/grappa/test.py", line 153, in _trigger
raise err
AssertionError: Oops! Something went wrong!
The following assertion was not satisfied
subject "[1, 2, 3]" should be have length of "4"
Message
subject list must have at least 4 items
Reasons
▸ unexpected object length: 3
What we expected
an object that can be length measured and its length is equal to 4
What we got instead
an object of type "list" with length 3
Information
▸ Object length is measured by using "len()" built-in
Python function or consuming an lazy iterable, such as a
generator. Most built-in types and objects in Python
can be tested that way, such as str, list, tuple, dict...
as well as any object that implements "__len__()" method.
— Reference: https://docs.python.org/3/library/functions.html#len
Where
File "grappa/tests/should_test.py", line 16, in test_grappa_assert
8|
9| def test_native_assert():
10| x = [1, 2, 3]
11| assert len(x) == 4
12|
13|
14| def test_grappa_assert():
15| x = [1, 2, 3]
16| > x | should.be.have.length.of(4)
17|
18|
19| def test_bool():
20| True | should.be.true | should.be.present
21| False | should.be.false | should.be.equal.to(False)
22| False | should.be.false | should.not_be.equal.to(True)
.. image:: https://asciinema.org/a/d6yd2475m41thdku7d3ntkeir.png :width: 900 :alt: showcase :align: center :target: https://asciinema.org/a/d6yd2475m41thdku7d3ntkeir?autoplay=1&speed=3&size=small
grappa aims to assist humans while doing a very recurrent and not very fun task in software development: testing things.
The core idea behind grappa comes from the fact that human time is considerably more expensive than machine time,
and therefore any machine assistance to optimize processes and close the gap is beneficial.
With grappa you can express almost in plain English what the test contract actually is, but in a way that's
fun and easy to write but also more easy and pleasant to read or maintain by other developers.
expect and should assertion styles.assertion operators_.error reporting_.plugins_.and & or.unittest, nosetests, pytest, behave ...Using pip package manager:
.. code-block:: bash
pip install --upgrade grappa
Or install the latest sources from Github:
.. code-block:: bash
pip install -e git+git://github.com/grappa-py/grappa.git#egg=grappa
.. _Python: http://python.org
.. _documentation: http://grappa.readthedocs.io
.. _operators documentation: http://grappa.readthedocs.io/en/latest/operators.html
.. _tutorial: http://grappa.readthedocs.io/en/latest/tutorial.html
.. _plugins: http://grappa.readthedocs.io/en/latest/plugins.html
.. _error reporting: http://grappa.readthedocs.io/en/latest/errors.html
.. _assertion styles: http://grappa.readthedocs.io/en/latest/style.html
.. _assertion operators: http://grappa.readthedocs.io/en/latest/operators.html
.. _grappa-http: https://github.com/grappa-py/http
.. |Build Status| image:: https://travis-ci.org/grappa-py/grappa.svg?branch=master :target: https://travis-ci.org/grappa-py/grappa .. |PyPI| image:: https://img.shields.io/pypi/v/grappa.svg?maxAge=2592000?style=flat-square :target: https://pypi.python.org/pypi/grappa .. |Coverage Status| image:: https://coveralls.io/repos/github/grappa-py/grappa/badge.svg?branch=master :target: https://coveralls.io/github/grappa-py/grappa?branch=master .. |Documentation Status| image:: https://readthedocs.org/projects/grappa/badge/?version=latest :target: http://grappa.readthedocs.io/en/latest/?badge=latest .. |Quality| image:: https://codeclimate.com/github/grappa-py/grappa/badges/gpa.svg :target: https://codeclimate.com/github/grappa-py/grappa :alt: Code Climate .. |Stability| image:: https://img.shields.io/pypi/status/grappa.svg :target: https://pypi.python.org/pypi/grappa :alt: Stability .. |Versions| image:: https://img.shields.io/pypi/pyversions/grappa.svg :target: https://pypi.python.org/pypi/grappa :alt: Python Versions .. |SayThanks| image:: https://img.shields.io/badge/Say%20Thanks!-%F0%9F%A6%89-1EAEDB.svg :target: https://saythanks.io/to/h2non :alt: Say Thanks
only operator #45FAQs
Behavior-oriented, expressive, developer-friendly assertions library
We found that grappa demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 1 open source maintainer collaborating on the project.
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