From 9967fcc5ac3c84abbac3de8b9778efd5870b2314 Mon Sep 17 00:00:00 2001 From: Jason Madden Date: Wed, 17 Mar 2021 10:01:49 -0500 Subject: Update documentation and Provides repr for better debugging. Fixes #229. Replaces #232 --- src/zope/interface/declarations.py | 3 ++- src/zope/interface/ro.py | 23 +++++++++++++++++++++++ src/zope/interface/tests/test_declarations.py | 11 ++++++++--- 3 files changed, 33 insertions(+), 4 deletions(-) (limited to 'src') diff --git a/src/zope/interface/declarations.py b/src/zope/interface/declarations.py index 9a0146c..e6efbae 100644 --- a/src/zope/interface/declarations.py +++ b/src/zope/interface/declarations.py @@ -750,10 +750,11 @@ class Provides(Declaration): # Really named ProvidesClass Declaration.__init__(self, *(interfaces + (implementedBy(cls), ))) def __repr__(self): - return "<%s.%s for %s>" % ( + return "<%s.%s for instances of %s providing %s>" % ( self.__class__.__module__, self.__class__.__name__, self._cls, + self.__args[1:], ) def __reduce__(self): diff --git a/src/zope/interface/ro.py b/src/zope/interface/ro.py index 20338ed..89dde67 100644 --- a/src/zope/interface/ro.py +++ b/src/zope/interface/ro.py @@ -45,6 +45,10 @@ ZOPE_INTERFACE_STRICT_IRO If this is set to "1", any attempt to use :func:`ro` that would produce a non-C3 ordering will fail by raising :class:`InconsistentResolutionOrderError`. +.. important:: + + ``ZOPE_INTERFACE_STRICT_IRO`` is intended to become the default in the future. + There are two environment variables that are independent. ZOPE_INTERFACE_LOG_CHANGED_IRO @@ -56,6 +60,25 @@ ZOPE_INTERFACE_USE_LEGACY_IRO legacy IRO will be used instead. This is a temporary measure and will be removed in the future. It is intended to help during the transition. It implies ``ZOPE_INTERFACE_LOG_CHANGED_IRO``. + +.. rubric:: Debugging Behaviour Changes in zope.interface 5 + +Most behaviour changes from zope.interface 4 to 5 are related to +inconsistent resolution orders. ``ZOPE_INTERFACE_STRICT_IRO`` is the +most effective tool to find such inconsistent resolution orders, and +we recommend running your code with this variable set if at all +possible. Doing so will ensure that all interface resolution orders +are consistent, and if they're not, will immediately point the way to +where this is violated. + +Occasionally, however, this may not be enough. This is because in some +cases, a C3 ordering can be found (the resolution order is fully +consistent) that is substantially different from the ad-hoc legacy +ordering. In such cases, you may find that you get an unexpected value +returned when adapting one or more objects to an interface. To debug +this, *also* enable ``ZOPE_INTERFACE_LOG_CHANGED_IRO`` and examine the +output. The main thing to look for is changes in the relative +positions of interfaces for which there are registered adapters. """ from __future__ import print_function __docformat__ = 'restructuredtext' diff --git a/src/zope/interface/tests/test_declarations.py b/src/zope/interface/tests/test_declarations.py index 9ef192a..a52274a 100644 --- a/src/zope/interface/tests/test_declarations.py +++ b/src/zope/interface/tests/test_declarations.py @@ -1305,13 +1305,18 @@ class ProvidesClassTests(unittest.TestCase): self.assertRaises(AttributeError, _test) def test__repr__(self): - inst = self._makeOne(type(self)) + from zope.interface.interface import InterfaceClass + IFoo = InterfaceClass("IFoo") + + inst = self._makeOne(type(self), IFoo) self.assertEqual( repr(inst), - "" % type(self) + "" % ( + type(self), + (IFoo,) + ) ) - class Test_Provides(unittest.TestCase): def _callFUT(self, *args, **kw): -- cgit v1.2.1