ruff/crates/ty_python_semantic/resources/mdtest
David Peter 589e8ac0d9
[ty] Infer type for implicit self parameters in method bodies (#20922)
## Summary

Infer a type of `Self` for unannotated `self` parameters in methods of
classes.

part of https://github.com/astral-sh/ty/issues/159

closes https://github.com/astral-sh/ty/issues/1081

## Conformance tests changes

```diff
+enums_member_values.py:85:9: error[invalid-assignment] Object of type `int` is not assignable to attribute `_value_` of type `str`
```
A true positive ✔️ 

```diff
-generics_self_advanced.py:35:9: error[type-assertion-failure] Argument does not have asserted type `Self@method2`
-generics_self_basic.py:14:9: error[type-assertion-failure] Argument does not have asserted type `Self@set_scale
```

Two false positives going away ✔️ 

```diff
+generics_syntax_infer_variance.py:82:9: error[invalid-assignment] Cannot assign to final attribute `x` on type `Self@__init__`
```

This looks like a true positive to me, even if it's not marked with `#
E` ✔️

```diff
+protocols_explicit.py:56:9: error[invalid-assignment] Object of type `tuple[int, int, str]` is not assignable to attribute `rgb` of type `tuple[int, int, int]`
```

True positive ✔️ 

```
+protocols_explicit.py:85:9: error[invalid-attribute-access] Cannot assign to ClassVar `cm1` from an instance of type `Self@__init__`
```

This looks like a true positive to me, even if it's not marked with `#
E`. But this is consistent with our understanding of `ClassVar`, I
think. ✔️

```py
+qualifiers_final_annotation.py:52:9: error[invalid-assignment] Cannot assign to final attribute `ID4` on type `Self@__init__`
+qualifiers_final_annotation.py:65:9: error[invalid-assignment] Cannot assign to final attribute `ID7` on type `Self@method1`
```

New true positives ✔️ 

```py
+qualifiers_final_annotation.py:52:9: error[invalid-assignment] Cannot assign to final attribute `ID4` on type `Self@__init__`
+qualifiers_final_annotation.py:57:13: error[invalid-assignment] Cannot assign to final attribute `ID6` on type `Self@__init__`
+qualifiers_final_annotation.py:59:13: error[invalid-assignment] Cannot assign to final attribute `ID6` on type `Self@__init__`
```

This is a new false positive, but that's a pre-existing issue on main
(if you annotate with `Self`):
https://play.ty.dev/3ee1c56d-7e13-43bb-811a-7a81e236e6ab  => reported
as https://github.com/astral-sh/ty/issues/1409

## Ecosystem

* There are 5931 new `unresolved-attribute` and 3292 new
`possibly-missing-attribute` attribute errors, way too many to look at
all of them. I randomly sampled 15 of these errors and found:
* 13 instances where there was simply no such attribute that we could
plausibly see. Sometimes [I didn't find it
anywhere](8644d886c6/openlibrary/plugins/openlibrary/tests/test_listapi.py (L33)).
Sometimes it was set externally on the object. Sometimes there was some
[`setattr` dynamicness going
on](a49f6b927d/setuptools/wheel.py (L88-L94)).
I would consider all of them to be true positives.
* 1 instance where [attribute was set on `obj` in
`__new__`](9e87b44fd4/sympy/tensor/array/array_comprehension.py (L45C1-L45C36)),
which we don't support yet
  * 1 instance [where the attribute was defined via `__slots__`

](e250ec0fc8/lib/spack/spack/vendor/pyrsistent/_pdeque.py (L48C5-L48C14))
* I see 44 instances [of the false positive
above](https://github.com/astral-sh/ty/issues/1409) with `Final`
instance attributes being set in `__init__`. I don't think this should
block this PR.

## Test Plan

New Markdown tests.

---------

Co-authored-by: Shaygan Hooshyari <sh.hooshyari@gmail.com>
2025-10-23 09:34:39 +02:00
..
annotations [ty] Infer type for implicit self parameters in method bodies (#20922) 2025-10-23 09:34:39 +02:00
assignment [ty] Prefer declared type for invariant collection literals (#20927) 2025-10-16 16:11:28 -04:00
binary [ty] Sync vendored typeshed stubs (#20876) 2025-10-15 11:13:32 +02:00
boolean
boundness_declaredness [ty] Reformulation of public symbol inference test suite (#20667) 2025-10-01 14:26:17 +02:00
call [ty] Infer type for implicit self parameters in method bodies (#20922) 2025-10-23 09:34:39 +02:00
class [ty] Infer type for implicit self parameters in method bodies (#20922) 2025-10-23 09:34:39 +02:00
comparison [ty] detect cycles in binary comparison inference (#20446) 2025-09-17 09:45:25 +02:00
comprehensions [ty] Async for loops and async iterables (#19634) 2025-07-30 17:40:24 +02:00
conditional [ty] Support as-patterns in reachability analysis (#19728) 2025-08-04 20:13:50 +02:00
dataclasses [ty] dataclass_transform: Support for fields with an alias (#20961) 2025-10-18 18:20:39 +00:00
declaration
diagnostics [ty] continue and break statements outside loops are syntax errors (#20944) 2025-10-17 17:13:40 +00:00
directives [ty] Use annotated parameters as type context (#20635) 2025-10-03 17:14:51 -04:00
doc
exception [ty] Filter out revealed-type and undefined-reveal diagnostics from mdtest snapshots (#20820) 2025-10-12 18:39:32 +00:00
expression [ty] Improve error messages for unresolved attribute diagnostics (#20963) 2025-10-19 10:58:25 +01:00
function [ty] Improve disambiguation of types via fully qualified names (#20141) 2025-08-29 08:44:18 +00:00
generics [ty] Fix panic on recursive class definitions in a stub that use constrained type variables (#20955) 2025-10-18 13:02:55 +00:00
ide_support [ty] Filter out revealed-type and undefined-reveal diagnostics from mdtest snapshots (#20820) 2025-10-12 18:39:32 +00:00
import [ty] Improve error messages for unresolved attribute diagnostics (#20963) 2025-10-19 10:58:25 +01:00
literal [ty] Treat functions, methods, and dynamic types as function-like Callables (#20842) 2025-10-13 15:21:55 +02:00
loops [ty] Heterogeneous unpacking support for unions (#20377) 2025-10-15 19:30:03 +01:00
narrow [ty] Improve error messages for unresolved attribute diagnostics (#20963) 2025-10-19 10:58:25 +01:00
regression
scopes [ty] Improve error messages for unresolved attribute diagnostics (#20963) 2025-10-19 10:58:25 +01:00
shadowing
snapshots [ty] Infer type for implicit self parameters in method bodies (#20922) 2025-10-23 09:34:39 +02:00
stubs Update default and latest Python versions for 3.14 (#20725) 2025-10-07 12:23:11 -04:00
subscript [ty] Rename "possibly unbound" diagnostics to "possibly missing" (#20492) 2025-09-23 14:26:55 +00:00
suppressions [ty] Add suggestion to unknown rule diagnostics, rename unknown-rule lint to ignore-comment-unknown-rule (#20948) 2025-10-18 12:44:21 +02:00
type_compendium [ty] Heterogeneous unpacking support for unions (#20377) 2025-10-15 19:30:03 +01:00
type_of [ty] Improve the Display for generic type[] types (#19667) 2025-07-31 19:45:01 +01:00
type_properties [ty] Some more simplifications when rendering constraint sets (#21009) 2025-10-22 13:38:44 -04:00
type_qualifiers [ty] Infer type for implicit self parameters in method bodies (#20922) 2025-10-23 09:34:39 +02:00
unary
with [ty] Use typing.Self for the first parameter of instance methods (#20517) 2025-09-29 21:08:08 +02:00
.mdformat.toml
async.md [ty] Support async/await, async with and yield from (#19595) 2025-07-30 11:51:21 +02:00
attributes.md [ty] Infer type for implicit self parameters in method bodies (#20922) 2025-10-23 09:34:39 +02:00
bidirectional.md [ty] bidirectional type inference using function return type annotations (#20528) 2025-10-11 00:38:35 +00:00
classes.md [ty] don't assume that deferred type inference means deferred name resolution (#20160) 2025-08-29 16:19:45 -07:00
cycle.md [ty] Avoid ever-growing default types (#20991) 2025-10-21 19:13:36 +02:00
decorators.md
del.md [ty] No union with Unknown for module-global symbols (#20664) 2025-10-01 16:40:30 +02:00
deprecated.md [ty] Consistent use of American english (in rules) (#19488) 2025-07-22 16:10:38 +02:00
descriptor_protocol.md [ty] Infer type for implicit self parameters in method bodies (#20922) 2025-10-23 09:34:39 +02:00
enums.md [ty] Enums: allow multiple aliases to point to the same member (#20669) 2025-10-01 15:51:53 +02:00
exhaustiveness_checking.md [ty] Fix subtyping for dynamic specializations (#20592) 2025-09-26 15:05:03 +02:00
final.md
implicit_type_aliases.md [ty] no more diverging query cycles in type expressions (#20359) 2025-09-16 16:44:11 -07:00
instance_layout_conflict.md [ty] initial support for slots=True in dataclasses (#20278) 2025-09-07 18:25:35 +01:00
intersection_types.md [ty] Expansion of enums into unions of literals (#19382) 2025-07-21 19:37:55 +02:00
invalid_syntax.md
known_constants.md
mdtest_config.md
mdtest_custom_typeshed.md [ty] Remove Type::Tuple (#19669) 2025-08-11 22:03:32 +01:00
metaclass.md
mro.md [ty] Filter out revealed-type and undefined-reveal diagnostics from mdtest snapshots (#20820) 2025-10-12 18:39:32 +00:00
named_tuple.md [ty] Infer type for implicit self parameters in method bodies (#20922) 2025-10-23 09:34:39 +02:00
overloads.md [ty] Improve diagnostics for bad @overload definitions (#20745) 2025-10-07 21:52:57 +00:00
pep613_type_aliases.md [ty] Fall back to Divergent for deeply nested specializations (#20988) 2025-10-22 14:29:10 +02:00
pep695_type_aliases.md [ty] cache Type::is_redundant_with (#20477) 2025-10-16 13:46:56 +02:00
properties.md [ty] "foo".startswith is not an instance of types.MethodWrapperType (#20317) 2025-09-10 11:14:26 +00:00
protocols.md [ty] Fix panic when attempting to validate the members of a protocol that inherits from a protocol in another module (#20956) 2025-10-18 15:01:46 +01:00
public_types.md [ty] Disambiguate classes that live in different modules but have the same fully qualified names (#20756) 2025-10-08 18:27:40 +01:00
statically_known_branches.md [ty] Rename "possibly unbound" diagnostics to "possibly missing" (#20492) 2025-09-23 14:26:55 +00:00
sys_platform.md
sys_version_info.md
t_strings.md [ty] Add support for PEP 750 t-strings (#20085) 2025-08-25 18:49:49 +00:00
terminal_statements.md [ty] improve lazy scope place lookup (#19321) 2025-07-25 07:11:11 +00:00
ty_extensions.md [ty] Simplify and fix CallableTypeOf[..] implementation (#20797) 2025-10-10 12:04:37 +02:00
typed_dict.md [ty] Improve error messages for unresolved attribute diagnostics (#20963) 2025-10-19 10:58:25 +01:00
union_types.md [ty] Introduce TypeRelation::Redundancy (#20602) 2025-10-03 18:35:30 +01:00
unpacking.md [ty] Infer more precise types for collection literals (#20360) 2025-09-17 18:51:50 -04:00
unreachable.md [ty] Rename "possibly unbound" diagnostics to "possibly missing" (#20492) 2025-09-23 14:26:55 +00:00