[ty] Emit a diagnostic for subclassing with `order=True` #21704

charliermarsh · 2025-11-30T16:12:08Z

Summary

astral-sh-bot · 2025-11-30T16:14:07Z

Diagnostic diff on typing conformance tests

Changes were detected when running ty on typing conformance tests

--- old-output.txt	2025-11-30 16:19:49.924622031 +0000
+++ new-output.txt	2025-11-30 16:19:53.496646751 +0000
@@ -342,12 +342,14 @@
 dataclasses_transform_field.py:64:16: error[unknown-argument] Argument `id` does not match any known parameter
 dataclasses_transform_field.py:75:1: error[missing-argument] No argument provided for required parameter `name`
 dataclasses_transform_field.py:75:16: error[too-many-positional-arguments] Too many positional arguments: expected 0, got 1
+dataclasses_transform_func.py:45:25: warning[subclass-of-dataclass-with-order] Class `Customer2Subclass` inherits from dataclass `Customer2` which has `order=True`
 dataclasses_transform_func.py:56:1: error[invalid-assignment] Object of type `Literal[3]` is not assignable to attribute `name` of type `str`
 dataclasses_transform_func.py:60:6: error[unsupported-operator] Operator `<` is not supported for types `Customer1` and `Customer1`
 dataclasses_transform_func.py:64:36: error[unknown-argument] Argument `salary` does not match any known parameter
 dataclasses_transform_func.py:70:8: error[missing-argument] No arguments provided for required parameters `id`, `name`
 dataclasses_transform_func.py:70:18: error[too-many-positional-arguments] Too many positional arguments: expected 0, got 2
 dataclasses_transform_func.py:76:36: error[invalid-return-type] Function always implicitly returns `None`, which is not assignable to return type `T@create_model_frozen`
+dataclasses_transform_func.py:89:25: warning[subclass-of-dataclass-with-order] Class `Customer3Subclass` inherits from dataclass `Customer3` which has `order=True`
 dataclasses_transform_func.py:96:1: error[invalid-assignment] Property `id` defined in `Customer3` is read-only
 dataclasses_transform_meta.py:63:1: error[invalid-assignment] Property `id` defined in `Customer1` is read-only
 dataclasses_transform_meta.py:66:8: error[missing-argument] No arguments provided for required parameters `id`, `name`
@@ -1039,4 +1041,4 @@
 typeddicts_usage.py:28:17: error[missing-typed-dict-key] Missing required key 'name' in TypedDict `Movie` constructor
 typeddicts_usage.py:28:18: error[invalid-key] Unknown key "title" for TypedDict `Movie`: Unknown key "title"
 typeddicts_usage.py:40:24: error[invalid-type-form] The special form `typing.TypedDict` is not allowed in type expressions
-Found 1041 diagnostics
+Found 1043 diagnostics

astral-sh-bot · 2025-11-30T16:15:52Z

`mypy_primer` results

Changes were detected when running on open source projects

attrs (https://github.com/python-attrs/attrs)
+ tests/test_annotations.py:189:17: warning[subclass-of-dataclass-with-order] Class `B` inherits from dataclass `A` which has `order=True`
+ tests/test_annotations.py:194:17: warning[subclass-of-dataclass-with-order] Class `C` inherits from dataclass `A` which has `order=True`
+ tests/test_functional.py:69:11: warning[subclass-of-dataclass-with-order] Class `Sub` inherits from dataclass `Base` which has `order=True`
+ tests/test_functional.py:74:16: warning[subclass-of-dataclass-with-order] Class `SubSlots` inherits from dataclass `BaseSlots` which has `order=True`
+ tests/test_functional.py:84:17: warning[subclass-of-dataclass-with-order] Class `SubFrozen` inherits from dataclass `Frozen` which has `order=True`
+ tests/test_functional.py:365:28: warning[subclass-of-dataclass-with-order] Class `SubOverwrite` inherits from dataclass `Base` which has `order=True`
+ tests/test_functional.py:423:17: warning[subclass-of-dataclass-with-order] Class `D` inherits from dataclass `C` which has `order=True`
+ tests/test_functional.py:472:17: warning[subclass-of-dataclass-with-order] Class `D` inherits from dataclass `C` which has `order=True`
+ tests/test_functional.py:478:17: warning[subclass-of-dataclass-with-order] Class `E` inherits from dataclass `D` which has `order=True`
+ tests/test_functional.py:519:19: warning[subclass-of-dataclass-with-order] Class `Sub` inherits from dataclass `Base` which has `order=True`
+ tests/test_functional.py:663:17: warning[subclass-of-dataclass-with-order] Class `D` inherits from dataclass `C` which has `order=True`
+ tests/test_functional.py:684:17: warning[subclass-of-dataclass-with-order] Class `D` inherits from dataclass `C` which has `order=True`
+ tests/test_functional.py:733:17: warning[subclass-of-dataclass-with-order] Class `D` inherits from dataclass `C` which has `order=True`
+ tests/test_functional.py:767:26: warning[subclass-of-dataclass-with-order] Class `ToRegister` inherits from dataclass `Base` which has `order=True`
+ tests/test_hooks.py:199:19: warning[subclass-of-dataclass-with-order] Class `Sub` inherits from dataclass `Base` which has `order=True`
+ tests/test_init_subclass.py:22:19: warning[subclass-of-dataclass-with-order] Class `Vanilla` inherits from dataclass `Base` which has `order=True`
+ tests/test_init_subclass.py:40:17: warning[subclass-of-dataclass-with-order] Class `Attrs` inherits from dataclass `Base` which has `order=True`
+ tests/test_make.py:264:17: warning[subclass-of-dataclass-with-order] Class `C` inherits from dataclass `B` which has `order=True`
+ tests/test_make.py:356:17: warning[subclass-of-dataclass-with-order] Class `B` inherits from dataclass `A` which has `order=True`
+ tests/test_make.py:361:17: warning[subclass-of-dataclass-with-order] Class `C` inherits from dataclass `B` which has `order=True`
+ tests/test_make.py:361:20: warning[subclass-of-dataclass-with-order] Class `C` inherits from dataclass `A` which has `order=True`
+ tests/test_make.py:366:17: warning[subclass-of-dataclass-with-order] Class `D` inherits from dataclass `A` which has `order=True`
+ tests/test_make.py:371:17: warning[subclass-of-dataclass-with-order] Class `E` inherits from dataclass `C` which has `order=True`
+ tests/test_make.py:371:20: warning[subclass-of-dataclass-with-order] Class `E` inherits from dataclass `D` which has `order=True`
+ tests/test_make.py:390:17: warning[subclass-of-dataclass-with-order] Class `D` inherits from dataclass `C` which has `order=True`
+ tests/test_make.py:408:17: warning[subclass-of-dataclass-with-order] Class `B` inherits from dataclass `A` which has `order=True`
+ tests/test_make.py:413:17: warning[subclass-of-dataclass-with-order] Class `C` inherits from dataclass `B` which has `order=True`
+ tests/test_make.py:413:20: warning[subclass-of-dataclass-with-order] Class `C` inherits from dataclass `A` which has `order=True`
+ tests/test_make.py:418:17: warning[subclass-of-dataclass-with-order] Class `D` inherits from dataclass `A` which has `order=True`
+ tests/test_make.py:423:17: warning[subclass-of-dataclass-with-order] Class `E` inherits from dataclass `C` which has `order=True`
+ tests/test_make.py:423:20: warning[subclass-of-dataclass-with-order] Class `E` inherits from dataclass `D` which has `order=True`
+ tests/test_make.py:447:17: warning[subclass-of-dataclass-with-order] Class `B` inherits from dataclass `A` which has `order=True`
+ tests/test_make.py:451:17: warning[subclass-of-dataclass-with-order] Class `C` inherits from dataclass `A` which has `order=True`
+ tests/test_make.py:458:17: warning[subclass-of-dataclass-with-order] Class `D` inherits from dataclass `B` which has `order=True`
+ tests/test_make.py:458:20: warning[subclass-of-dataclass-with-order] Class `D` inherits from dataclass `C` which has `order=True`
+ tests/test_make.py:475:17: warning[subclass-of-dataclass-with-order] Class `B` inherits from dataclass `A` which has `order=True`
+ tests/test_make.py:479:17: warning[subclass-of-dataclass-with-order] Class `C` inherits from dataclass `B` which has `order=True`
+ tests/test_make.py:964:24: warning[subclass-of-dataclass-with-order] Class `SubClass` inherits from dataclass `BaseClass` which has `order=True`
+ tests/test_make.py:1086:17: warning[subclass-of-dataclass-with-order] Class `C` inherits from dataclass `Base` which has `order=True`
+ tests/test_make.py:1124:17: warning[subclass-of-dataclass-with-order] Class `C` inherits from dataclass `Base` which has `order=True`
+ tests/test_make.py:1138:17: warning[subclass-of-dataclass-with-order] Class `C` inherits from dataclass `Base` which has `order=True`
+ tests/test_make.py:1186:41: warning[subclass-of-dataclass-with-order] Class `KwArgBeforeInitFalseChild` inherits from dataclass `KwArgBeforeInitFalseParent` which has `order=True`
+ tests/test_make.py:2201:18: warning[subclass-of-dataclass-with-order] Class `C2` inherits from dataclass `C` which has `order=True`
+ tests/test_make.py:2220:18: warning[subclass-of-dataclass-with-order] Class `C2` inherits from dataclass `C` which has `order=True`
+ tests/test_make.py:2410:17: warning[subclass-of-dataclass-with-order] Class `B` inherits from dataclass `A` which has `order=True`
+ tests/test_setattr.py:240:22: warning[subclass-of-dataclass-with-order] Class `NoHook` inherits from dataclass `WithOnSetAttrHook` which has `order=True`
+ tests/test_setattr.py:271:17: warning[subclass-of-dataclass-with-order] Class `C` inherits from dataclass `B` which has `order=True`
+ tests/test_setattr.py:323:17: warning[subclass-of-dataclass-with-order] Class `B` inherits from dataclass `A` which has `order=True`
+ tests/test_setattr.py:340:39: warning[subclass-of-dataclass-with-order] Class `RemoveNeedForOurSetAttr` inherits from dataclass `WithOnSetAttrHook` which has `order=True`
+ tests/test_setattr.py:373:33: warning[subclass-of-dataclass-with-order] Class `CustomSetAttr` inherits from dataclass `Frozen` which has `order=True`
+ tests/test_setattr.py:413:17: warning[subclass-of-dataclass-with-order] Class `B` inherits from dataclass `A` which has `order=True`
+ tests/test_setattr.py:420:17: warning[subclass-of-dataclass-with-order] Class `C` inherits from dataclass `B` which has `order=True`
+ tests/test_slots.py:152:19: warning[subclass-of-dataclass-with-order] Class `C2Slots` inherits from dataclass `C1` which has `order=True`
+ tests/test_slots.py:248:19: warning[subclass-of-dataclass-with-order] Class `C2Slots` inherits from dataclass `C1Slots` which has `order=True`
+ tests/test_slots.py:252:14: warning[subclass-of-dataclass-with-order] Class `C2` inherits from dataclass `C1` which has `order=True`
+ tests/test_slots.py:294:19: warning[subclass-of-dataclass-with-order] Class `C2Slots` inherits from dataclass `C1Slots` which has `order=True`
+ tests/test_slots.py:454:18: warning[subclass-of-dataclass-with-order] Class `C2` inherits from dataclass `C1` which has `order=True`
+ tests/test_slots.py:459:23: warning[subclass-of-dataclass-with-order] Class `C2Slots` inherits from dataclass `C1Slots` which has `order=True`
+ tests/test_slots.py:573:13: warning[subclass-of-dataclass-with-order] Class `D` inherits from dataclass `C` which has `order=True`
+ tests/test_slots.py:699:13: warning[subclass-of-dataclass-with-order] Class `B` inherits from dataclass `A` which has `order=True`
+ tests/test_slots.py:705:13: warning[subclass-of-dataclass-with-order] Class `C` inherits from dataclass `A` which has `order=True`
+ tests/test_slots.py:730:13: warning[subclass-of-dataclass-with-order] Class `B` inherits from dataclass `A` which has `order=True`
+ tests/test_slots.py:901:13: warning[subclass-of-dataclass-with-order] Class `B` inherits from dataclass `A` which has `order=True`
+ tests/test_slots.py:928:13: warning[subclass-of-dataclass-with-order] Class `B` inherits from dataclass `A` which has `order=True`
+ tests/test_slots.py:955:13: warning[subclass-of-dataclass-with-order] Class `B` inherits from dataclass `A` which has `order=True`
+ tests/test_slots.py:989:14: warning[subclass-of-dataclass-with-order] Class `AB` inherits from dataclass `A` which has `order=True`
+ tests/test_slots.py:989:17: warning[subclass-of-dataclass-with-order] Class `AB` inherits from dataclass `B` which has `order=True`
+ tests/test_slots.py:1009:13: warning[subclass-of-dataclass-with-order] Class `B` inherits from dataclass `A` which has `order=True`
+ tests/test_slots.py:1031:13: warning[subclass-of-dataclass-with-order] Class `B` inherits from dataclass `A` which has `order=True`
+ tests/test_slots.py:1054:13: warning[subclass-of-dataclass-with-order] Class `B` inherits from dataclass `A` which has `order=True`
+ typing-examples/mypy.py:83:10: warning[subclass-of-dataclass-with-order] Class `GG` inherits from dataclass `DD` which has `order=True`
+ typing-examples/mypy.py:91:10: warning[subclass-of-dataclass-with-order] Class `HH` inherits from dataclass `DD` which has `order=True`
+ typing-examples/mypy.py:91:14: warning[subclass-of-dataclass-with-order] Class `HH` inherits from dataclass `EE` which has `order=True`
- Found 606 diagnostics
+ Found 679 diagnostics

Expression (https://github.com/cognitedata/Expression)
+ expression/core/try_.py:17:11: warning[subclass-of-dataclass-with-order] Class `Try` inherits from dataclass `Result` which has `order=True`
- Found 211 diagnostics
+ Found 212 diagnostics

strawberry (https://github.com/strawberry-graphql/strawberry)
+ strawberry/relay/types.py:745:22: warning[subclass-of-dataclass-with-order] Class `ListConnection` inherits from dataclass `Connection` which has `order=True`
- Found 400 diagnostics
+ Found 401 diagnostics

materialize (https://github.com/MaterializeInc/materialize)
+ misc/python/materialize/output_consistency/ignore_filter/ignore_verdict.py:18:17: warning[subclass-of-dataclass-with-order] Class `YesIgnore` inherits from dataclass `IgnoreVerdict` which has `order=True`
+ misc/python/materialize/output_consistency/ignore_filter/ignore_verdict.py:27:16: warning[subclass-of-dataclass-with-order] Class `NoIgnore` inherits from dataclass `IgnoreVerdict` which has `order=True`
- Found 3371 diagnostics
+ Found 3373 diagnostics

pydantic (https://github.com/pydantic/pydantic)
- pydantic/fields.py:943:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, Divergent] | ((dict[str, Divergent], /) -> None) | None`
+ pydantic/fields.py:943:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, int | float | str | ... omitted 3 union elements] | ((dict[str, int | float | str | ... omitted 3 union elements], /) -> None) | None`
- pydantic/fields.py:983:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, Divergent] | ((dict[str, Divergent], /) -> None) | None`
+ pydantic/fields.py:983:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, int | float | str | ... omitted 3 union elements] | ((dict[str, int | float | str | ... omitted 3 union elements], /) -> None) | None`
- pydantic/fields.py:1026:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, Divergent] | ((dict[str, Divergent], /) -> None) | None`
+ pydantic/fields.py:1026:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, int | float | str | ... omitted 3 union elements] | ((dict[str, int | float | str | ... omitted 3 union elements], /) -> None) | None`
- pydantic/fields.py:1066:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, Divergent] | ((dict[str, Divergent], /) -> None) | None`
+ pydantic/fields.py:1066:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, int | float | str | ... omitted 3 union elements] | ((dict[str, int | float | str | ... omitted 3 union elements], /) -> None) | None`
- pydantic/fields.py:1109:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, Divergent] | ((dict[str, Divergent], /) -> None) | None`
+ pydantic/fields.py:1109:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, int | float | str | ... omitted 3 union elements] | ((dict[str, int | float | str | ... omitted 3 union elements], /) -> None) | None`
- pydantic/fields.py:1148:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, Divergent] | ((dict[str, Divergent], /) -> None) | None`
+ pydantic/fields.py:1148:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, int | float | str | ... omitted 3 union elements] | ((dict[str, int | float | str | ... omitted 3 union elements], /) -> None) | None`
- pydantic/fields.py:1188:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, Divergent] | ((dict[str, Divergent], /) -> None) | None`
+ pydantic/fields.py:1188:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, int | float | str | ... omitted 3 union elements] | ((dict[str, int | float | str | ... omitted 3 union elements], /) -> None) | None`
- pydantic/fields.py:1567:13: error[invalid-argument-type] Argument is incorrect: Expected `dict[str, Divergent] | ((dict[str, Divergent], /) -> None) | None`, found `Top[dict[Unknown, Unknown]] | (((dict[str, Divergent], /) -> None) & ~Top[dict[Unknown, Unknown]]) | None`
+ pydantic/fields.py:1567:13: error[invalid-argument-type] Argument is incorrect: Expected `dict[str, int | float | str | ... omitted 3 union elements] | ((dict[str, int | float | str | ... omitted 3 union elements], /) -> None) | None`, found `Top[dict[Unknown, Unknown]] | (((dict[str, int | float | str | ... omitted 3 union elements], /) -> None) & ~Top[dict[Unknown, Unknown]]) | None`

No memory usage changes detected ✅

charliermarsh · 2025-11-30T16:18:50Z

I believe those changes on the conformance tests are "correct" in-so-far as those are instances of the case we want to catch here.

astral-sh-bot · 2025-11-30T16:38:29Z

`ecosystem-analyzer` results

Lint rule	Added	Removed
`subclass-of-dataclass-with-order`	77	0
`invalid-argument-type`	0	2
`unsupported-base`	0	2
Total	77	4

Full report with detailed diff (timing results)

AlexWaygood

Nice!

AlexWaygood · 2025-12-01T18:54:54Z

crates/ty_python_semantic/resources/mdtest/dataclasses/dataclasses.md

+classes in the inheritance hierarchy will raise a `TypeError` at runtime. This violates the Liskov
+Substitution Principle:


Suggested change

classes in the inheritance hierarchy will raise a `TypeError` at runtime. This violates the Liskov

Substitution Principle:

classes in the inheritance hierarchy will raise a `TypeError` at runtime. The design of the stdlib

feature therefore violates the Liskov Substitution Principle:

AlexWaygood · 2025-12-01T18:57:58Z

crates/ty_python_semantic/resources/mdtest/liskov.md


-# TODO: specifying `order=True` on the subclass means that a `__lt__` method is
-# generated that is incompatible with the generated `__lt__` method on the superclass.
-# We could consider detecting this and emitting a diagnostic, though maybe it shouldn't
-# be `invalid-method-override` since we'd emit it on the class definition rather than
-# on any method definition. Note also that no other type checker complains about this
-# as of 2025-11-21.
+# Specifying `order=True` on the subclass means that a `__lt__` method is generated that
+# is incompatible with the generated `__lt__` method on the superclass. We emit a diagnostic
+# on the class definition because the design of `order=True` dataclasses themselves violates
+# the Liskov Substitution Principle.
 @dataclass(order=True)
-class Bar2(Foo):
+class Bar2(Foo):  # error: [subclass-of-dataclass-with-order]
    y: str


I wonder if we should suppress the subclass-of-dataclass-with-order diagnostic if all the comparison methods are overridden on the subclass? (That's the case here, since Bar2 is also decorated with order=True.) This case here does feel like it should be flagged using the error code we use for Liskov Subsitution Principle violations, because by specifying order=True the user has in a sense explicitly asked for an incompatible override.

And something like the following also seems safe, if the user has taken care to override all the unsound methods from the superclass:

from dataclasses import dataclass @dataclass(order=True) class A: int class B(A): def __lt__(self, other: A) -> bool: return True def __le__(self, other: A) -> bool: return True __gt__ = __lt__ __ge__ = __le__

AlexWaygood · 2025-12-01T19:01:18Z

crates/ty_python_semantic/src/types/infer/builder.rs

+                if let Some(base_params) = base_class_literal.dataclass_params(self.db()) {
+                    if base_params.flags(self.db()).contains(DataclassFlags::ORDER) {
+                        if let Some(builder) = self
+                            .context
+                            .report_lint(&SUBCLASS_OF_DATACLASS_WITH_ORDER, &class_node.bases()[i])
+                        {
+                            builder.into_diagnostic(format_args!(
+                                "Class `{}` inherits from dataclass `{}` which has `order=True`",
+                                class.name(self.db()),
+                                base_class.name(self.db()),
+                            ));
+                        }
+                    }
+                }


can we add an info subdiagnostic here explaining why this is problematic?

AlexWaygood · 2025-12-01T19:01:52Z

crates/ty_python_semantic/src/types/diagnostic.rs

+    /// class Parent:
+    ///     value: int
+    ///
+    /// class Child(Parent):  # Error raised here


Suggested change

/// class Child(Parent): # Error raised here

/// class Child(Parent): # Ty emits an error here

AlexWaygood · 2025-12-01T19:02:38Z

crates/ty_python_semantic/src/types/diagnostic.rs

+    /// Consider using `functools.total_ordering` instead, which does not have this limitation.
+    ///
+    /// [Liskov Substitution Principle]: https://en.wikipedia.org/wiki/Liskov_substitution_principle


Suggested change

/// Consider using `functools.total_ordering` instead, which does not have this limitation.

///

/// [Liskov Substitution Principle]: https://en.wikipedia.org/wiki/Liskov_substitution_principle

/// Consider using [`functools.total_ordering`][total_ordering] instead, which does not have this limitation.

///

/// [Liskov Substitution Principle]: https://en.wikipedia.org/wiki/Liskov_substitution_principle

/// [total_ordering]: https://docs.python.org/3/library/functools.html#functools.total_ordering

charliermarsh requested review from AlexWaygood, MichaReiser, carljm, dcreager and sharkdp as code owners November 30, 2025 16:12

charliermarsh changed the title ~~Emit a diagnostic for subclassing with order=True~~ [ty] Emit a diagnostic for subclassing with order=True Nov 30, 2025

charliermarsh added the ty Multi-file analysis & type inference label Nov 30, 2025

Emit a diagnostic for subclassing with order=True

4e4b08c

charliermarsh force-pushed the charlie/order branch from bc1c309 to 4e4b08c Compare November 30, 2025 16:18

MichaReiser added the ecosystem-analyzer label Nov 30, 2025

AlexWaygood reviewed Dec 1, 2025

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[ty] Emit a diagnostic for subclassing with `order=True` #21704

[ty] Emit a diagnostic for subclassing with `order=True` #21704

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charliermarsh commented Nov 30, 2025

Uh oh!

astral-sh-bot bot commented Nov 30, 2025 •

edited

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astral-sh-bot bot commented Nov 30, 2025 •

edited

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charliermarsh commented Nov 30, 2025

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		classes in the inheritance hierarchy will raise a `TypeError` at runtime. This violates the Liskov
		Substitution Principle:

	/// class Child(Parent): # Error raised here
	/// class Child(Parent): # Ty emits an error here

[ty] Emit a diagnostic for subclassing with order=True #21704

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[ty] Emit a diagnostic for subclassing with order=True #21704

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charliermarsh commented Nov 30, 2025

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Diagnostic diff on typing conformance tests

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mypy_primer results

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ecosystem-analyzer results

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[ty] Emit a diagnostic for subclassing with `order=True` #21704

[ty] Emit a diagnostic for subclassing with `order=True` #21704

astral-sh-bot bot commented Nov 30, 2025 •

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`mypy_primer` results

`ecosystem-analyzer` results