Skip to main content
Join the official Python Developers Survey 2018 and win valuable prizes: Start the survey!

Verify interface contract for all implements/classImplements declaration

Project description

Introduction

What’s the use to declare an interface if your class doesn’t implement correctly the interface ?

Of course you should verify that in a test but if you don’t want to write a test to check that all your code really implements the promised interfaces use this package.

It’s a simple patch that calls zope.interface.verify.verifyClass once you declare implementing an interface and print the BrokenImplementation or BrokenMethodImplementation as a warning (if any).

Simple example in testrunner:

By default the egg enable interface contract verification for zope.interface.implements and zope.interface.classImplements that are present in all your packages:

>>> write('buildout.cfg',
... """
... [buildout]
... parts =
...     test
...
... [test]
... recipe = zc.recipe.testrunner
... eggs = affinitic.verifyinterface
...        zope.exceptions
... defaults = ['-m', 'module']
... """)

>>> print system(buildout)
Installing test.
...

>>> from os.path import join
>>> print system(join('bin', 'test')),
<class 'affinitic.verifyinterface.tests.test_module1.Foo'> failed implementing <InterfaceClass affinitic.verifyinterface.tests.test_module1.IFoo>: An object has failed to implement interface <InterfaceClass affinitic.verifyinterface.tests.test_module1.IFoo>
<BLANKLINE>
        The bla attribute was not provided.
<BLANKLINE>
<class 'affinitic.verifyinterface.tests.test_module2.Bar'> failed implementing <InterfaceClass affinitic.verifyinterface.tests.test_module2.IBar>: An object has failed to implement interface <InterfaceClass affinitic.verifyinterface.tests.test_module2.IBar>
<BLANKLINE>
        The bla attribute was not provided.
<BLANKLINE>
Running zope.testing.testrunner.layer.UnitTests tests:
  Set up zope.testing.testrunner.layer.UnitTests in 0.000 seconds.
  Ran 2 tests with 0 failures and 0 errors in 0.000 seconds.
Tearing down left over layers:
  Tear down zope.testing.testrunner.layer.UnitTests in 0.000 seconds.

Limit verifications

But you can limit the package where this verification needs to be done (sometimes you don’t care that a package you depend on didn’t implement correctly an interface).

This is done by adding an environment variable verifyinterface where you specify what packages/modules (separated by n as usual) you accept to verify interfaces.

Here is a simple example where I only want to have warning for bad implementation of interfaces used by module1:

>>> write('buildout.cfg',
... """
... [buildout]
... parts =
...     test
...
... [test]
... recipe = zc.recipe.testrunner
... eggs = affinitic.verifyinterface
...        zope.exceptions
... defaults = ['-m', 'module']
... environment = testenv
...
... [testenv]
... verifyinterface = affinitic.verifyinterface.tests.test_module1
... """)

>>> print system(buildout)
Uninstalling test.
Installing test.
...

>>> from os.path import join
>>> print system(join('bin', 'test'))
<class 'affinitic.verifyinterface.tests.test_module1.Foo'> failed implementing <InterfaceClass affinitic.verifyinterface.tests.test_module1.IFoo>: An object has failed to implement interface <InterfaceClass affinitic.verifyinterface.tests.test_module1.IFoo>
<BLANKLINE>
        The bla attribute was not provided.
<BLANKLINE>
Running zope.testing.testrunner.layer.UnitTests tests:
  Set up zope.testing.testrunner.layer.UnitTests in 0.000 seconds.
  Ran 2 tests with 0 failures and 0 errors in 0.000 seconds.
Tearing down left over layers:
  Tear down zope.testing.testrunner.layer.UnitTests in 0.000 seconds.

Changelog

0.1 (2009-12-18)

  • Initial release

Project details


Release history Release notifications

This version
History Node

0.1

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Filename, size & hash SHA256 hash help File type Python version Upload date
affinitic.verifyinterface-0.1.tar.gz (4.6 kB) Copy SHA256 hash SHA256 Source None Dec 18, 2009

Supported by

Elastic Elastic Search Pingdom Pingdom Monitoring Google Google BigQuery Sentry Sentry Error logging AWS AWS Cloud computing DataDog DataDog Monitoring Fastly Fastly CDN SignalFx SignalFx Supporter DigiCert DigiCert EV certificate StatusPage StatusPage Status page