Merge pull request #764 from twisted/attrs-provides-deprecation

address removal of `attrs.validators.provides`

requirements/tox-pin-base.txt

@@ -1,4 +1,4 @@
-attrs==23.2.0
+attrs==24.2.0
 Automat==22.10.0
 characteristic==14.3.0
 constantly==15.1.0

src/klein/_attrs_zope.py

@@ -0,0 +1,47 @@
+from __future__ import annotations
+
+import attrs
+from zope.interface import Interface
+
+
+@attrs.define(repr=False)
+class _ProvidesValidator:
+    interface: type[Interface] = attrs.field()
+
+    def __call__(
+        self, inst: object, attr: attrs.Attribute, value: object
+    ) -> None:
+        """
+        We use a callable class to be able to change the ``__repr__``.
+        """
+        if not self.interface.providedBy(value):
+            msg = (
+                f"'{attr.name}' must provide {self.interface!r} "
+                f"which {value!r} doesn't."
+            )
+            raise TypeError(
+                msg,
+                attr,
+                self.interface,
+                value,
+            )
+
+    def __repr__(self) -> str:
+        return f"<provides validator for interface {self.interface!r}>"
+
+
+def provides(interface: type[Interface]) -> _ProvidesValidator:
+    """
+    A validator that raises a `TypeError` if the initializer is called
+    with an object that does not provide the requested *interface* (checks are
+    performed using ``interface.providedBy(value)`` (see `zope.interface
+    <https://zopeinterface.readthedocs.io/en/latest/>`_).
+
+    :param interface: The interface to check for.
+    :type interface: ``zope.interface.Interface``
+
+    :raises TypeError: With a human readable error message, the attribute
+        (of type `attrs.Attribute`), the expected interface, and the
+        value it got.
+    """
+    return _ProvidesValidator(interface)

src/klein/_request.py

@@ -8,11 +8,12 @@
 from typing import Union
 
 from attr import Factory, attrib, attrs
-from attr.validators import instance_of, provides
+from attr.validators import instance_of
 from hyperlink import DecodedURL
 from tubes.itube import IFount
 from zope.interface import implementer
 
+from ._attrs_zope import provides
 from ._imessage import IHTTPHeaders, IHTTPRequest
 from ._message import MessageState, bodyAsBytes, bodyAsFount, validateBody
 

src/klein/_request_compat.py

@@ -9,14 +9,14 @@
 from typing import cast
 
 from attr import Factory, attrib, attrs
-from attr.validators import provides
 from hyperlink import DecodedURL
 from tubes.itube import IFount
 from zope.interface import implementer
 
 from twisted.python.compat import nativeString
 from twisted.web.iweb import IRequest
 
+from ._attrs_zope import provides
 from ._headers import IHTTPHeaders
 from ._headers_compat import HTTPHeadersWrappingHeaders
 from ._message import FountAlreadyAccessedError, MessageState

src/klein/_response.py

@@ -8,10 +8,11 @@
 from typing import Union
 
 from attr import Factory, attrib, attrs
-from attr.validators import instance_of, provides
+from attr.validators import instance_of
 from tubes.itube import IFount
 from zope.interface import implementer
 
+from ._attrs_zope import provides
 from ._imessage import IHTTPHeaders, IHTTPResponse
 from ._message import MessageState, bodyAsBytes, bodyAsFount, validateBody
 

src/klein/_tubes.py

@@ -8,14 +8,16 @@
 from typing import Any, BinaryIO
 
 from attr import attrib, attrs
-from attr.validators import instance_of, optional, provides
+from attr.validators import instance_of, optional
 from tubes.itube import IDrain, IFount, ISegment
 from tubes.kit import Pauser, beginFlowingTo
 from tubes.undefer import fountToDeferred
 from zope.interface import implementer
 
 from twisted.python.failure import Failure
 
+from ._attrs_zope import provides
+
 
 __all__ = ()
 

src/klein/test/test_attrs_zope.py

@@ -0,0 +1,39 @@
+from __future__ import annotations
+
+import attrs
+from zope.interface import Interface, implementer
+
+from twisted.trial.unittest import SynchronousTestCase
+
+from .._attrs_zope import provides
+
+
+class IWhatever(Interface):
+    ...
+
+
+@implementer(IWhatever)
+class YesWhatever:
+    ...
+
+
+class NoWhatever:
+    ...
+
+
+@attrs.define()
+class WhateverContainer:
+    whatever: object = attrs.field(validator=provides(IWhatever))
+
+
+class ProvidesTestCase(SynchronousTestCase):
+    def test_yes(self) -> None:
+        WhateverContainer(YesWhatever())
+
+    def test_no(self) -> None:
+        with self.assertRaises(TypeError):
+            WhateverContainer(NoWhatever())
+
+    def test_repr(self) -> None:
+        self.assertIn("provides validator for", repr(provides(IWhatever)))
+        self.assertIn("IWhatever", repr(provides(IWhatever)))