Conformance: drop questionable non-data-descriptor dataclass tests

conformance/results/mypy/dataclasses_descriptors.toml

@@ -1,18 +1,6 @@
-conformant = "Partial"
-notes = """
-Assumes descriptor behavior only when field is assigned in class body.
-Does not correctly evaluate type of descriptor access.
-"""
+conformant = "Pass"
 output = """
-dataclasses_descriptors.py:61: error: Cannot access instance-only attribute "x" on class object  [misc]
-dataclasses_descriptors.py:62: error: Cannot access instance-only attribute "y" on class object  [misc]
-dataclasses_descriptors.py:66: error: Expression is of type "Desc2[int]", not "int"  [assert-type]
-dataclasses_descriptors.py:67: error: Expression is of type "Desc2[str]", not "str"  [assert-type]
 """
-conformance_automated = "Fail"
+conformance_automated = "Pass"
 errors_diff = """
-Line 61: Unexpected errors ['dataclasses_descriptors.py:61: error: Cannot access instance-only attribute "x" on class object  [misc]']
-Line 62: Unexpected errors ['dataclasses_descriptors.py:62: error: Cannot access instance-only attribute "y" on class object  [misc]']
-Line 66: Unexpected errors ['dataclasses_descriptors.py:66: error: Expression is of type "Desc2[int]", not "int"  [assert-type]']
-Line 67: Unexpected errors ['dataclasses_descriptors.py:67: error: Expression is of type "Desc2[str]", not "str"  [assert-type]']
 """

conformance/results/pycroscope/dataclasses_descriptors.toml

@@ -1,23 +1,6 @@
-conformant = "Partial"
-notes = """
-Conformance suite is questionable; see https://github.com/python/typing/issues/2259
-"""
-conformance_automated = "Fail"
+conformant = "Pass"
+conformance_automated = "Pass"
 errors_diff = """
-Line 61: Unexpected errors ['./dataclasses_descriptors.py:61:12:   Any[error] is not equivalent to list[int]', "./dataclasses_descriptors.py:61:12: <class 'DC2'> has no attribute 'x' [undefined_attribute]"]
-Line 62: Unexpected errors ['./dataclasses_descriptors.py:62:12:   Any[error] is not equivalent to list[str]', "./dataclasses_descriptors.py:62:12: <class 'DC2'> has no attribute 'y' [undefined_attribute]"]
-Line 63: Unexpected errors ['./dataclasses_descriptors.py:63:12:   list[Any[generic_argument]] is not equivalent to list[str]']
-Line 66: Unexpected errors ['./dataclasses_descriptors.py:66:12:   ./dataclasses_descriptors.py.Desc2[int] is not equivalent to int']
-Line 67: Unexpected errors ['./dataclasses_descriptors.py:67:12:   ./dataclasses_descriptors.py.Desc2[str] is not equivalent to str']
-Line 68: Unexpected errors ['./dataclasses_descriptors.py:68:12:   Any[generic_argument] is not equivalent to str']
 """
 output = """
-./dataclasses_descriptors.py:61:12:   Any[error] is not equivalent to list[int]
-./dataclasses_descriptors.py:61:12: <class 'DC2'> has no attribute 'x' [undefined_attribute]
-./dataclasses_descriptors.py:62:12:   Any[error] is not equivalent to list[str]
-./dataclasses_descriptors.py:62:12: <class 'DC2'> has no attribute 'y' [undefined_attribute]
-./dataclasses_descriptors.py:63:12:   list[Any[generic_argument]] is not equivalent to list[str]
-./dataclasses_descriptors.py:66:12:   ./dataclasses_descriptors.py.Desc2[int] is not equivalent to int
-./dataclasses_descriptors.py:67:12:   ./dataclasses_descriptors.py.Desc2[str] is not equivalent to str
-./dataclasses_descriptors.py:68:12:   Any[generic_argument] is not equivalent to str
 """

conformance/results/pyrefly/dataclasses_descriptors.toml

@@ -1,22 +1,11 @@
 conformant = "Partial"
 notes = """
-* Assumes descriptor behavior only when field is assigned in class body
-* Doesn't allow non-data descriptors or data descriptors with differing `__get__` and `__set__` types
+Rejects a data descriptor field whose `__get__` and `__set__` have differing types.
 """
 conformance_automated = "Fail"
 errors_diff = """
-Line 32: Unexpected errors ['Cannot set field `y` to data descriptor `Desc1` with inconsistent types [bad-class-definition]']
-Line 58: Unexpected errors ['Cannot set field `z` to non-data descriptor `Desc2` [bad-class-definition]']
-Line 61: Unexpected errors ['assert_type(Desc2[int], list[int]) failed [assert-type]']
-Line 62: Unexpected errors ['assert_type(Desc2[str], list[str]) failed [assert-type]']
-Line 66: Unexpected errors ['assert_type(Desc2[int], int) failed [assert-type]']
-Line 67: Unexpected errors ['assert_type(Desc2[str], str) failed [assert-type]']
+Line 35: Unexpected errors ['Cannot set field `y` to data descriptor `Desc1` with inconsistent types [bad-class-definition]']
 """
 output = """
-ERROR dataclasses_descriptors.py:32:5-6: Cannot set field `y` to data descriptor `Desc1` with inconsistent types [bad-class-definition]
-ERROR dataclasses_descriptors.py:58:5-6: Cannot set field `z` to non-data descriptor `Desc2` [bad-class-definition]
-ERROR dataclasses_descriptors.py:61:12-30: assert_type(Desc2[int], list[int]) failed [assert-type]
-ERROR dataclasses_descriptors.py:62:12-30: assert_type(Desc2[str], list[str]) failed [assert-type]
-ERROR dataclasses_descriptors.py:66:12-24: assert_type(Desc2[int], int) failed [assert-type]
-ERROR dataclasses_descriptors.py:67:12-24: assert_type(Desc2[str], str) failed [assert-type]
+ERROR dataclasses_descriptors.py:35:5-6: Cannot set field `y` to data descriptor `Desc1` with inconsistent types [bad-class-definition]
 """

conformance/results/results.html

@@ -900,12 +900,12 @@ <h3>Python Type System Conformance Test Results</h3>
 <a class="test_group" href="https://typing.readthedocs.io/en/latest/spec/dataclasses.html">Dataclasses</a>
 </th></tr>
 <tr><th class="column col1">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;dataclasses_descriptors</th>
-<th class="column col2 partially-conformant"><div class="hover-text">Partial<span class="tooltip-text" id="bottom"><p>Assumes descriptor behavior only when field is assigned in class body.</p><p>Does not correctly evaluate type of descriptor access.</p></span></div></th>
 <th class="column col2 conformant">Pass</th>
 <th class="column col2 conformant">Pass</th>
-<th class="column col2 partially-conformant"><div class="hover-text">Partial<span class="tooltip-text" id="bottom"><p>* Assumes descriptor behavior only when field is assigned in class body</p><p>* Doesn't allow non-data descriptors or data descriptors with differing `__get__` and `__set__` types</p></span></div></th>
-<th class="column col2 partially-conformant"><div class="hover-text">Partial<span class="tooltip-text" id="bottom"><p>Conformance suite is questionable; see https://github.com/python/typing/issues/2259</p></span></div></th>
-<th class="column col2 partially-conformant"><div class="hover-text">Partial<span class="tooltip-text" id="bottom"><p>Only infers a descriptor `__get__` method as being called when a descriptor attribute is accessed on an instance if the descriptor attribute is present in the class namespace.</p></span></div></th>
+<th class="column col2 conformant">Pass</th>
+<th class="column col2 partially-conformant"><div class="hover-text">Partial<span class="tooltip-text" id="bottom"><p>Rejects a data descriptor field whose `__get__` and `__set__` have differing types.</p></span></div></th>
+<th class="column col2 conformant">Pass</th>
+<th class="column col2 conformant">Pass</th>
 </tr>
 <tr><th class="column col1">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;dataclasses_final</th>
 <th class="column col2 partially-conformant"><div class="hover-text">Partial<span class="tooltip-text" id="bottom"><p>Wrongly requires a Final dataclass field to be initialized at class level.</p><p>Doesn't support Final nested inside ClassVar.</p></span></div></th>

conformance/results/ty/dataclasses_descriptors.toml

@@ -1,13 +1,6 @@
-conformance_automated = "Fail"
-conformant = "Partial"
-notes = """
-Only infers a descriptor `__get__` method as being called when a descriptor attribute is accessed on an instance if the descriptor attribute is present in the class namespace.
-"""
+conformance_automated = "Pass"
+conformant = "Pass"
 errors_diff = """
-Line 66: Unexpected errors ['dataclasses_descriptors.py:66:1: error[type-assertion-failure] Type `int | Desc2[int]` does not match asserted type `int`']
-Line 67: Unexpected errors ['dataclasses_descriptors.py:67:1: error[type-assertion-failure] Type `str | Desc2[str]` does not match asserted type `str`']
 """
 output = """
-dataclasses_descriptors.py:66:1: error[type-assertion-failure] Type `int | Desc2[int]` does not match asserted type `int`
-dataclasses_descriptors.py:67:1: error[type-assertion-failure] Type `str | Desc2[str]` does not match asserted type `str`
 """

conformance/tests/dataclasses_descriptors.py

@@ -2,13 +2,16 @@
 Tests the handling of descriptors within a dataclass.
 """
 
-# This portion of the dataclass spec is under-specified in the documentation,
-# but its behavior can be determined from the runtime implementation.
+# A data descriptor used as a dataclass field is handled according to the
+# runtime implementation: the field type is the type returned by ``__get__``.
+#
+# The behavior of non-data descriptors (descriptors with only ``__get__``) used
+# as dataclass fields is under-specified and type checkers disagree, so those
+# cases are intentionally omitted here. See
+# https://github.com/python/typing/issues/2259.
 
 from dataclasses import dataclass
-from typing import Any, Generic, TypeVar, assert_type, overload
-
-T = TypeVar("T")
+from typing import Any, assert_type, overload
 
 
 class Desc1:
@@ -36,33 +39,3 @@ class DC1:
 
 assert_type(dc1.y, int)
 assert_type(DC1.y, Desc1)
-
-
-class Desc2(Generic[T]):
-    @overload
-    def __get__(self, instance: None, owner: Any) -> list[T]:
-        ...
-
-    @overload
-    def __get__(self, instance: object, owner: Any) -> T:
-        ...
-
-    def __get__(self, instance: object | None, owner: Any) -> list[T] | T:
-        raise NotImplementedError
-
-
-@dataclass
-class DC2:
-    x: Desc2[int]
-    y: Desc2[str]
-    z: Desc2[str] = Desc2()
-
-
-assert_type(DC2.x, list[int])
-assert_type(DC2.y, list[str])
-assert_type(DC2.z, list[str])
-
-dc2 = DC2(Desc2(), Desc2(), Desc2())
-assert_type(dc2.x, int)
-assert_type(dc2.y, str)
-assert_type(dc2.z, str)