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-rw-r--r--src/zope/interface/exceptions.py92
-rw-r--r--src/zope/interface/tests/test_exceptions.py54
-rw-r--r--src/zope/interface/tests/test_verify.py33
-rw-r--r--src/zope/interface/verify.py153
4 files changed, 247 insertions, 85 deletions
diff --git a/src/zope/interface/exceptions.py b/src/zope/interface/exceptions.py
index 8d21f33..86caf3f 100644
--- a/src/zope/interface/exceptions.py
+++ b/src/zope/interface/exceptions.py
@@ -20,6 +20,7 @@ __all__ = [
'DoesNotImplement',
'BrokenImplementation',
'BrokenMethodImplementation',
+ 'MultipleInvalid',
# Other
'BadImplements',
'InvalidInterface',
@@ -29,18 +30,37 @@ class Invalid(Exception):
"""A specification is violated
"""
-_NotGiven = object()
+_NotGiven = '<Not Given>'
class _TargetMixin(object):
target = _NotGiven
+ interface = None
@property
- def _prefix(self):
+ def _target_prefix(self):
if self.target is _NotGiven:
return "An object"
return "The object %r" % (self.target,)
-class DoesNotImplement(Invalid, _TargetMixin):
+ _trailer = '.'
+
+ @property
+ def _general_description(self):
+ return "has failed to implement interface %s:" % (
+ self.interface
+ ) if self.interface is not None else ''
+
+
+ def __str__(self):
+ return "%s %s%s%s" % (
+ self._target_prefix,
+ self._general_description,
+ self._specifics,
+ self._trailer
+ )
+
+
+class DoesNotImplement(_TargetMixin, Invalid):
"""
The *target* (optional) does not implement the *interface*.
@@ -50,17 +70,17 @@ class DoesNotImplement(Invalid, _TargetMixin):
"""
def __init__(self, interface, target=_NotGiven):
- Invalid.__init__(self)
+ Invalid.__init__(self, interface, target)
self.interface = interface
self.target = target
- def __str__(self):
- return "%s does not implement the interface %s." % (
- self._prefix,
- self.interface
- )
+ _general_description = "does not implement the interface"
-class BrokenImplementation(Invalid, _TargetMixin):
+ @property
+ def _specifics(self):
+ return ' ' + str(self.interface)
+
+class BrokenImplementation(_TargetMixin, Invalid):
"""
The *target* (optional) is missing the attribute *name*.
@@ -72,19 +92,19 @@ class BrokenImplementation(Invalid, _TargetMixin):
"""
def __init__(self, interface, name, target=_NotGiven):
- Invalid.__init__(self)
+ Invalid.__init__(self, interface, name, target)
self.interface = interface
self.name = name
self.target = target
- def __str__(self):
- return "%s has failed to implement interface %s: The %s attribute was not provided." % (
- self._prefix,
- self.interface,
+
+ @property
+ def _specifics(self):
+ return " The %s attribute was not provided" % (
repr(self.name) if isinstance(self.name, str) else self.name
)
-class BrokenMethodImplementation(Invalid, _TargetMixin):
+class BrokenMethodImplementation(_TargetMixin, Invalid):
"""
The *target* (optional) has a *method* that violates
its contract in a way described by *mess*.
@@ -97,19 +117,49 @@ class BrokenMethodImplementation(Invalid, _TargetMixin):
"""
def __init__(self, method, mess, target=_NotGiven):
- Invalid.__init__(self)
+ Invalid.__init__(self, method, mess, target)
self.method = method
self.mess = mess
self.target = target
- def __str__(self):
- return "%s violates its contract in %s: %s." % (
- self._prefix,
+ @property
+ def _specifics(self):
+ return 'violates the contract of %s because %s' % (
repr(self.method) if isinstance(self.method, str) else self.method,
- self.mess
+ self.mess,
)
+class MultipleInvalid(_TargetMixin, Invalid):
+ """
+ The *target* has failed to implement the *iface* in
+ multiple ways.
+
+ The failures are described by *exceptions*, a collection of
+ other `Invalid` instances.
+
+ .. versionadded:: 5.0
+ """
+
+ def __init__(self, iface, target, exceptions):
+ exceptions = list(exceptions)
+ Invalid.__init__(self, iface, target, exceptions)
+ self.target = target
+ self.interface = iface
+ self.exceptions = exceptions
+
+ @property
+ def _specifics(self):
+ # It would be nice to use tabs here, but that
+ # is hard to represent in doctests.
+ return '\n ' + '\n '.join(
+ x._specifics.strip() if isinstance(x, _TargetMixin) else(str(x))
+ for x in self.exceptions
+ )
+
+ _trailer = ''
+
+
class InvalidInterface(Exception):
"""The interface has invalid contents
"""
diff --git a/src/zope/interface/tests/test_exceptions.py b/src/zope/interface/tests/test_exceptions.py
index 34ee071..42ea7eb 100644
--- a/src/zope/interface/tests/test_exceptions.py
+++ b/src/zope/interface/tests/test_exceptions.py
@@ -85,10 +85,60 @@ class BrokenMethodImplementationTests(unittest.TestCase):
dni = self._makeOne()
self.assertEqual(
str(dni),
- "An object violates its contract in 'aMethod': I said so.")
+ "An object violates the contract of 'aMethod' because I said so.")
def test___str__w_candidate(self):
dni = self._makeOne('candidate')
self.assertEqual(
str(dni),
- "The object 'candidate' violates its contract in 'aMethod': I said so.")
+ "The object 'candidate' violates the contract of 'aMethod' because I said so.")
+
+ def test___repr__w_candidate(self):
+ dni = self._makeOne('candidate')
+ self.assertEqual(
+ repr(dni),
+ "BrokenMethodImplementation('aMethod', 'I said so', 'candidate')"
+ )
+
+
+class MultipleInvalidTests(unittest.TestCase):
+
+ def _getTargetClass(self):
+ from zope.interface.exceptions import MultipleInvalid
+ return MultipleInvalid
+
+ def _makeOne(self, excs):
+ iface = _makeIface()
+ return self._getTargetClass()(iface, 'target', excs)
+
+ def test__str__(self):
+ from zope.interface.exceptions import BrokenMethodImplementation
+ excs = [
+ BrokenMethodImplementation('aMethod', 'I said so'),
+ Exception("Regular exception")
+ ]
+ dni = self._makeOne(excs)
+ self.assertEqual(
+ str(dni),
+ "The object 'target' has failed to implement interface "
+ "<InterfaceClass zope.interface.tests.test_exceptions.IDummy>:\n"
+ " violates the contract of 'aMethod' because I said so\n"
+ " Regular exception"
+ )
+
+ def test__repr__(self):
+ from zope.interface.exceptions import BrokenMethodImplementation
+ excs = [
+ BrokenMethodImplementation('aMethod', 'I said so'),
+ # Use multiple arguments to normalize repr; versions of Python
+ # prior to 3.7 add a trailing comma if there's just one.
+ Exception("Regular", "exception")
+ ]
+ dni = self._makeOne(excs)
+ self.assertEqual(
+ repr(dni),
+ "MultipleInvalid(<InterfaceClass zope.interface.tests.test_exceptions.IDummy>,"
+ " 'target',"
+ " [BrokenMethodImplementation('aMethod', 'I said so', '<Not Given>'),"
+ " Exception('Regular', 'exception')])"
+ )
diff --git a/src/zope/interface/tests/test_verify.py b/src/zope/interface/tests/test_verify.py
index 65e390a..3a68d20 100644
--- a/src/zope/interface/tests/test_verify.py
+++ b/src/zope/interface/tests/test_verify.py
@@ -554,6 +554,39 @@ class Test_verifyClass(unittest.TestCase):
self._callFUT(IReadSequence, tuple, tentative=True)
+ def test_multiple_invalid(self):
+ from zope.interface.exceptions import MultipleInvalid
+ from zope.interface.exceptions import DoesNotImplement
+ from zope.interface.exceptions import BrokenImplementation
+ from zope.interface import Interface
+ from zope.interface import classImplements
+
+ class ISeveralMethods(Interface):
+ def meth1(arg1):
+ "Method 1"
+ def meth2(arg1):
+ "Method 2"
+
+ class SeveralMethods(object):
+ pass
+
+ with self.assertRaises(MultipleInvalid) as exc:
+ self._callFUT(ISeveralMethods, SeveralMethods)
+
+ ex = exc.exception
+ self.assertEqual(3, len(ex.exceptions))
+ self.assertIsInstance(ex.exceptions[0], DoesNotImplement)
+ self.assertIsInstance(ex.exceptions[1], BrokenImplementation)
+ self.assertIsInstance(ex.exceptions[2], BrokenImplementation)
+
+ # If everything else is correct, only the single error is raised without
+ # the wrapper.
+ classImplements(SeveralMethods, ISeveralMethods)
+ SeveralMethods.meth1 = lambda self, arg1: "Hi"
+
+ with self.assertRaises(BrokenImplementation):
+ self._callFUT(ISeveralMethods, SeveralMethods)
+
class Test_verifyObject(Test_verifyClass):
@classmethod
diff --git a/src/zope/interface/verify.py b/src/zope/interface/verify.py
index a8dd952..a9b80a7 100644
--- a/src/zope/interface/verify.py
+++ b/src/zope/interface/verify.py
@@ -21,8 +21,12 @@ from types import MethodType
from zope.interface._compat import PYPY2
-from zope.interface.exceptions import BrokenImplementation, DoesNotImplement
+from zope.interface.exceptions import BrokenImplementation
from zope.interface.exceptions import BrokenMethodImplementation
+from zope.interface.exceptions import DoesNotImplement
+from zope.interface.exceptions import Invalid
+from zope.interface.exceptions import MultipleInvalid
+
from zope.interface.interface import fromMethod, fromFunction, Method
__all__ = [
@@ -55,8 +59,16 @@ def _verify(iface, candidate, tentative=False, vtype=None):
- Making sure the candidate defines all the necessary attributes
+ :return bool: Returns a true value if everything that could be
+ checked passed.
:raises zope.interface.Invalid: If any of the previous
conditions does not hold.
+
+ .. versionchanged:: 5.0
+ If multiple methods or attributes are invalid, all such errors
+ are collected and reported. Previously, only the first error was reported.
+ As a special case, if only one such error is present, it is raised
+ alone, like before.
"""
if vtype == 'c':
@@ -64,74 +76,91 @@ def _verify(iface, candidate, tentative=False, vtype=None):
else:
tester = iface.providedBy
+ excs = []
if not tentative and not tester(candidate):
- raise DoesNotImplement(iface)
+ excs.append(DoesNotImplement(iface))
- # Here the `desc` is either an `Attribute` or `Method` instance
for name, desc in iface.namesAndDescriptions(all=True):
try:
- attr = getattr(candidate, name)
- except AttributeError:
- if (not isinstance(desc, Method)) and vtype == 'c':
- # We can't verify non-methods on classes, since the
- # class may provide attrs in it's __init__.
- continue
-
- raise BrokenImplementation(iface, desc, candidate)
-
- if not isinstance(desc, Method):
- # If it's not a method, there's nothing else we can test
- continue
-
- if inspect.ismethoddescriptor(attr) or inspect.isbuiltin(attr):
- # The first case is what you get for things like ``dict.pop``
- # on CPython (e.g., ``verifyClass(IFullMapping, dict))``). The
- # second case is what you get for things like ``dict().pop`` on
- # CPython (e.g., ``verifyObject(IFullMapping, dict()))``.
- # In neither case can we get a signature, so there's nothing
- # to verify. Even the inspect module gives up and raises
- # ValueError: no signature found. The ``__text_signature__`` attribute
- # isn't typically populated either.
- #
- # Note that on PyPy 2 or 3 (up through 7.3 at least), these are
- # not true for things like ``dict.pop`` (but might be true for C extensions?)
- continue
-
- if isinstance(attr, FunctionType):
- if sys.version_info[0] >= 3 and isinstance(candidate, type) and vtype == 'c':
- # This is an "unbound method" in Python 3.
- # Only unwrap this if we're verifying implementedBy;
- # otherwise we can unwrap @staticmethod on classes that directly
- # provide an interface.
- meth = fromFunction(attr, iface, name=name,
- imlevel=1)
- else:
- # Nope, just a normal function
- meth = fromFunction(attr, iface, name=name)
- elif (isinstance(attr, MethodTypes)
- and type(attr.__func__) is FunctionType):
- meth = fromMethod(attr, iface, name)
- elif isinstance(attr, property) and vtype == 'c':
- # We without an instance we cannot be sure it's not a
- # callable.
- continue
- else:
- if not callable(attr):
- raise BrokenMethodImplementation(desc, "implementation is not a method", candidate)
- # sigh, it's callable, but we don't know how to introspect it, so
- # we have to give it a pass.
- continue
-
- # Make sure that the required and implemented method signatures are
- # the same.
- mess = _incompat(desc.getSignatureInfo(), meth.getSignatureInfo())
- if mess:
- if PYPY2 and _pypy2_false_positive(mess, candidate, vtype):
- continue
- raise BrokenMethodImplementation(desc, mess, candidate)
+ _verify_element(iface, name, desc, candidate, vtype)
+ except Invalid as e:
+ excs.append(e)
+
+ if excs:
+ if len(excs) == 1:
+ raise excs[0]
+ raise MultipleInvalid(iface, candidate, excs)
return True
+def _verify_element(iface, name, desc, candidate, vtype):
+ # Here the `desc` is either an `Attribute` or `Method` instance
+ try:
+ attr = getattr(candidate, name)
+ except AttributeError:
+ if (not isinstance(desc, Method)) and vtype == 'c':
+ # We can't verify non-methods on classes, since the
+ # class may provide attrs in it's __init__.
+ return
+
+ raise BrokenImplementation(iface, desc, candidate)
+
+ if not isinstance(desc, Method):
+ # If it's not a method, there's nothing else we can test
+ return
+
+ if inspect.ismethoddescriptor(attr) or inspect.isbuiltin(attr):
+ # The first case is what you get for things like ``dict.pop``
+ # on CPython (e.g., ``verifyClass(IFullMapping, dict))``). The
+ # second case is what you get for things like ``dict().pop`` on
+ # CPython (e.g., ``verifyObject(IFullMapping, dict()))``.
+ # In neither case can we get a signature, so there's nothing
+ # to verify. Even the inspect module gives up and raises
+ # ValueError: no signature found. The ``__text_signature__`` attribute
+ # isn't typically populated either.
+ #
+ # Note that on PyPy 2 or 3 (up through 7.3 at least), these are
+ # not true for things like ``dict.pop`` (but might be true for C extensions?)
+ return
+
+ if isinstance(attr, FunctionType):
+ if sys.version_info[0] >= 3 and isinstance(candidate, type) and vtype == 'c':
+ # This is an "unbound method" in Python 3.
+ # Only unwrap this if we're verifying implementedBy;
+ # otherwise we can unwrap @staticmethod on classes that directly
+ # provide an interface.
+ meth = fromFunction(attr, iface, name=name,
+ imlevel=1)
+ else:
+ # Nope, just a normal function
+ meth = fromFunction(attr, iface, name=name)
+ elif (isinstance(attr, MethodTypes)
+ and type(attr.__func__) is FunctionType):
+ meth = fromMethod(attr, iface, name)
+ elif isinstance(attr, property) and vtype == 'c':
+ # Without an instance we cannot be sure it's not a
+ # callable.
+ # TODO: This should probably check inspect.isdatadescriptor(),
+ # a more general form than ``property``
+ return
+
+ else:
+ if not callable(attr):
+ raise BrokenMethodImplementation(desc, "implementation is not a method", candidate)
+ # sigh, it's callable, but we don't know how to introspect it, so
+ # we have to give it a pass.
+ return
+
+ # Make sure that the required and implemented method signatures are
+ # the same.
+ mess = _incompat(desc.getSignatureInfo(), meth.getSignatureInfo())
+ if mess:
+ if PYPY2 and _pypy2_false_positive(mess, candidate, vtype):
+ return
+ raise BrokenMethodImplementation(desc, mess, candidate)
+
+
+
def verifyClass(iface, candidate, tentative=False):
"""
Verify that the *candidate* might correctly provide *iface*.
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