Compatibility fixes. (#193)

* Restore hash to validators.

* Restore Attribute.default and Attribute.validator.

* _AndValidator is hashable now. Test validator hashability.

* Add in_ to validators.__all__.

CHANGELOG.rst

@@ -24,7 +24,9 @@ Deprecations:
 Changes:
 ^^^^^^^^
 
-*none*
+- Validators are hashable again.
+  Note that validators may become frozen in the future, pending availability of no-overhead frozen classes.
+  `#192 <https://github.com/python-attrs/attrs/issues/192>`_
 
 
 ----

src/attr/_make.py

@@ -818,14 +818,14 @@ class Attribute(object):
         "convert", "metadata",
     )
 
-    def __init__(self, name, _default, _validator, repr, cmp, hash, init,
+    def __init__(self, name, default, validator, repr, cmp, hash, init,
                  convert=None, metadata=None):
         # Cache this descriptor here to speed things up later.
         bound_setattr = _obj_setattr.__get__(self, Attribute)
 
         bound_setattr("name", name)
-        bound_setattr("default", _default)
+        bound_setattr("default", default)
-        bound_setattr("validator", _validator)
+        bound_setattr("validator", validator)
         bound_setattr("repr", repr)
         bound_setattr("cmp", cmp)
         bound_setattr("hash", hash)
@@ -842,12 +842,13 @@ class Attribute(object):
         inst_dict = {
             k: getattr(ca, k)
             for k
-            in Attribute.__slots__ + ("_validator", "_default")
+            in Attribute.__slots__
-            if k != "name" and k not in (
+            if k not in (
-                "validator", "default",
+                "name", "validator", "default",
             )  # exclude methods
         }
-        return cls(name=name, **inst_dict)
+        return cls(name=name, validator=ca._validator, default=ca._default,
+                   **inst_dict)
 
     # Don't use _add_pickle since fields(Attribute) doesn't work
     def __getstate__(self):
@@ -871,7 +872,7 @@ class Attribute(object):
                               _empty_metadata_singleton)
 
 
-_a = [Attribute(name=name, _default=NOTHING, _validator=None,
+_a = [Attribute(name=name, default=NOTHING, validator=None,
                 repr=True, cmp=True, hash=(name != "metadata"), init=True)
       for name in Attribute.__slots__]
 
@@ -892,12 +893,12 @@ class _CountingAttr(object):
     __slots__ = ("counter", "_default", "repr", "cmp", "hash", "init",
                  "metadata", "_validator", "convert")
     __attrs_attrs__ = tuple(
-        Attribute(name=name, _default=NOTHING, _validator=None,
+        Attribute(name=name, default=NOTHING, validator=None,
                   repr=True, cmp=True, hash=True, init=True)
         for name
         in ("counter", "_default", "repr", "cmp", "hash", "init",)
     ) + (
-        Attribute(name="metadata", _default=None, _validator=None,
+        Attribute(name="metadata", default=None, validator=None,
                   repr=True, cmp=True, hash=False, init=True),
     )
     cls_counter = 0
@@ -1015,7 +1016,7 @@ def make_class(name, attrs, bases=(object,), **attributes_arguments):
 # import into .validators.
 
 
-@attributes(slots=True)
+@attributes(slots=True, hash=True)
 class _AndValidator(object):
     """
     Compose many validators to a single one.

src/attr/validators.py

@@ -9,13 +9,14 @@ from ._make import attr, attributes, and_, _AndValidator
 
 __all__ = [
     "and_",
+    "in_",
     "instance_of",
     "optional",
     "provides",
 ]
 
 
-@attributes(repr=False, slots=True)
+@attributes(repr=False, slots=True, hash=True)
 class _InstanceOfValidator(object):
     type = attr()
 
@@ -55,7 +56,7 @@ def instance_of(type):
     return _InstanceOfValidator(type)
 
 
-@attributes(repr=False, slots=True)
+@attributes(repr=False, slots=True, hash=True)
 class _ProvidesValidator(object):
     interface = attr()
 
@@ -94,7 +95,7 @@ def provides(interface):
     return _ProvidesValidator(interface)
 
 
-@attributes(repr=False, slots=True)
+@attributes(repr=False, slots=True, hash=True)
 class _OptionalValidator(object):
     validator = attr()
 
@@ -129,7 +130,7 @@ def optional(validator):
     return _OptionalValidator(validator)
 
 
-@attributes(repr=False, slots=True)
+@attributes(repr=False, slots=True, hash=True)
 class _InValidator(object):
     options = attr()
 

tests/test_dark_magic.py

@@ -109,9 +109,9 @@ class TestDarkMagic(object):
         `attr.fields` works.
         """
         assert (
-            Attribute(name="x", _default=foo, _validator=None,
+            Attribute(name="x", default=foo, validator=None,
                       repr=True, cmp=True, hash=None, init=True),
-            Attribute(name="y", _default=attr.Factory(list), _validator=None,
+            Attribute(name="y", default=attr.Factory(list), validator=None,
                       repr=True, cmp=True, hash=None, init=True),
         ) == attr.fields(cls)
 
@@ -158,9 +158,9 @@ class TestDarkMagic(object):
         """
         PC = attr.make_class("PC", ["a", "b"], slots=slots, frozen=frozen)
         assert (
-            Attribute(name="a", _default=NOTHING, _validator=None,
+            Attribute(name="a", default=NOTHING, validator=None,
                       repr=True, cmp=True, hash=None, init=True),
-            Attribute(name="b", _default=NOTHING, _validator=None,
+            Attribute(name="b", default=NOTHING, validator=None,
                       repr=True, cmp=True, hash=None, init=True),
         ) == attr.fields(PC)
 

tests/test_validators.py

@@ -7,6 +7,7 @@ from __future__ import absolute_import, division, print_function
 import pytest
 import zope.interface
 
+from attr import validators as validator_module, has
 from attr.validators import and_, instance_of, provides, optional, in_
 from attr._compat import TYPE
 from attr._make import attributes, attr
@@ -248,3 +249,16 @@ class TestIn_(object):
         assert(
             ("<in_ validator with options [3, 4, 5]>")
         ) == repr(v)
+
+
+def test_hashability():
+    """
+    Validator classes are hashable.
+    """
+    for obj_name in dir(validator_module):
+        obj = getattr(validator_module, obj_name)
+        if not has(obj):
+            continue
+        hash_func = getattr(obj, '__hash__', None)
+        assert hash_func is not None
+        assert hash_func is not object.__hash__

tests/utils.py

@@ -35,7 +35,7 @@ def simple_attr(name, default=NOTHING, validator=None, repr=True,
     Return an attribute with a name and no other bells and whistles.
     """
     return Attribute(
-        name=name, _default=default, _validator=validator, repr=repr,
+        name=name, default=default, validator=validator, repr=repr,
         cmp=cmp, hash=hash, init=init
     )
 
@@ -166,7 +166,7 @@ def simple_attrs_with_metadata(draw):
     vals = st.booleans() | st.binary() | st.integers() | st.text()
     metadata = draw(st.dictionaries(keys=keys, values=vals))
 
-    return attr.ib(c_attr.default, c_attr._validator, c_attr.repr,
+    return attr.ib(c_attr._default, c_attr._validator, c_attr.repr,
                    c_attr.cmp, c_attr.hash, c_attr.init, c_attr.convert,
                    metadata)