Pyright

Bug Fix: Fixed bug in argument-matching code that produced false positive errors when a keyword argument corresponded to a positional-only argument name but should have been matched to a **kwargs parameter instead.

Bug Fix: Fixed bug in bidirectional type inference logic for list and dict expressions when expected type included a type varaible.

Bug Fix: Disabled the "self" annotation checks for overloaded methods because the self annotation can be used as a legitimate filter for overloads.

Enhancement: Improved bidirectional type inference for set expressions so it better handles unions in expected type.

Bug Fix: Improved TypeVar constraint solver so it provides a better solution when a TypeVar is constrained first by a contravariant wide bound in a first argument and then a subsequent argument relies on bidirectional type inference with a covariant or invariant use of the same TypeVar.

Bug Fix: Fixed bug that caused a crash in the type checker when a protocol class inherited from a generic non-protocol class.

Enhancement: Added check for a class that inherits from Generic to ensure that all type variables are included in the Generic subscript list.

Bug Fix: Fixed regression in handling expressions of the form `[x] * y`. Some previously-added special-case code to handle the `[None] * n` case was too general.

Enhancement: Changed printed types to fully expand type aliases in error messages where that additional detail is needed — namely, for "partially unknown" messages. This makes for verbose types, but without the expansion, it can be very difficult to determine which part of the type is unknown.

Bug Fix: Fixed false positive error in type compatibility check where the destination type is `Type[Any]` and the source type is `Type[x]` where x is anything (including `Any`).

Enhancement: Added exemption to the overlapping overload check for the `__get__` method. Other type checkers (namely mypy) exempt this method also.

Bug Fix: Fixed bug in type evaluator that resulted in suppressed errors and evaluations when the evaluation of a lambda expression resulted in some form of recursion (e.g. it references a symbol that depends on the return result of the lambda).

Enhancement: Added "reportTypedDictNotRequiredAccess" diagnostic rule and split out diagnostics that pertain specifically to unguarded accesses to non-required TypedDict keys.

Bug Fix: Changed type of `__path__` variable in module from `List[str]` to `Iterable[str]`.

Bug Fix: Fixed bug that resulted in a runtime crash within the type checker when a protocol class inherits from another protocol class that is not generic (like "Sized").

Enhancement: Added better heuristics to auto-complete insertion logic so it honors single-symbol-per-line and multi-symbol-per-line formats of "from x import a" statements.

Enhancement: Implemented a new check to validate that annotated types for "self" and "cls" parameters are supertypes of their containing classes.

Bug Fix (from pylance): Fixed bug that resulted in crashes when a broken symlink was encountered.

Bug Fix: Fixed recent regression that resulted in false positives when checking the type of a "self" parameter within a metaclass when the type annotation was of the form `Type[T]`.

Enhancement: Added minimal support for "no_type_check" decorator. It does not suppress errors, but it doesn't generate an error itself.

Enhancement: Added support for PEP 612 ParamSpecs to be used as type parameters for generic classes and generic type aliases. Previously, they were allowed only in the specialization of `Callable`.

Enhancement: Added out-of-bounds access check for index operations where the indexed type is a tuple object with known length and the index value is a negative integer literal value.

Bug Fix: Fixed bugs in the handling of PEP 487 `__init_subclass__`. The logic was using the `__init_subclass__` defined in the class itself rather than its base classes.

Enhancement: Added special-case handling for generic functions that return a `Callable` with generic parameters. The change allows for callers to pass type variables to the function and then have the resulting `Callable` provide a TypeVar scope for those variables.

Bug Fix (from pylance): Fixed bugs relating to partial type stub packages.

Bug Fix: Fixed bug that affected the use of the `tuple` constructor. It was not properly updating the variadic type arguments. This resulted in false negatives for the resulting type.

Bug Fix: Fixed bug that resulted in false negatives because diagnostics generated while analyzing a constructor call were suppressed.

Enhancement: Improved stub generator to print "x = ..." rather than include the RHS expression if `x` is not a type alias.

Enhancement: Added special-case handling for assignments of the form `x: List[A] = [a] * y` (the multiply operator on a list). This specific idiom is commonly used to initialize a list with None values.

Performance: Added perf improvements that help when dealing with unions that contain many tuples. Improved TypeVar constraint solver to better handle the case where a type is widened to include hundreds of subtypes, thus grinding performance to a halt. This occurs in one of the modules in pytorch.

Enhancement: Rewrote package type verifier based on feedback from users. Its error messages are now much clearer, it distinguishes between "exported symbols" and "other referenced symbols", it properly handles properties, and it omits warnings about missing docstrings by default (can be overridden with "--verbose" setting).

Bug Fix: Fixed bug that resulted in incorrect type evaluation for a constructor call when the class's `__new__` method returns an instance of a different class.

Bug Fix: Disabled the "always False comparison" check for expressions like "sys.platform == 'win32'" because they can vary depending on environment.

Enhancement: Added error check for a class that attempts to derive from NamedTuple and other base classes. This is not supported and will generate runtime exceptions.

Enhancement: Improved type checking for generators. Fixed several false negatives and false positives relating to "yield from" expressions.

Enhancement: Changed special-case logic for `self` annotations used with `__init__` methods to accommodate new usages in typeshed stubs.

Enhancement: Updated typeshed stubs to latest.

Bug Fix: Fixed bug in TypeVar constraint solver that resulted in a false positive when using the built-in "filter" method with the "os.path.exists" callback.

Bug Fix: Fixed bug where "comparison chaining" was not being appropriately applied to expressions that contained "is", "is not", "in" and "not in" operators in a chain (e.g. "1" in "1" == "1").

Enhancement: Added smarter handling of empty lists (`[]`) and dicts (`{}`). Previously, these were inferred to have types `list[Unknown]` and `dict[Unknown, Unknown]`, respectively. They are now provided with a known type if the variable is assigned a known list or dict type along another code path.

Bug Fix (from pylance): Made hover text, signature help, and completion suggestions show function docstring using same code.

Bug Fix (from pylance): Fixed issue with partial stub files in cases where a stub file is found but no corresponding source (.py) file is found.

Bug Fix: Fixed bug where a keyword parameter with a generic type (a TypeVar) and a default value of "..." caused the TypeVar to be assigned a value of "Any".

Bug Fix: Fixed recent regression that caused certain diagnostics to be suppressed when calling a constructor with an expected type.

Enhancement: Added missing check indicated in PEP 589 for TypedDict fields that override a parent class field by the same name with a different type.

Bug Fix: Added support for TypeVar where the bound or constrained types are literals.

Behavior Change: Changed "stubPath is not a valid directory" logging from an error to a warning. The fact that the value defaults to "typings" and most users don't have a typings folder results in confusion, so a warning is more appropriate here.

Enhancement: Updated typeshed stubs.

Bug Fix: Fixed bug that resulted in false negatives when a generic class was used within a subscript (e.g. within the type argument of another type) and no type arguments were specified for the generic class. This also resulted in such types not properly getting default values. For example, in the expression `Union[int, Callable]`, the `Callable` was not being interpreted as `Callable[..., Unknown]`.

Enhancement: Improved error message for partially-unknown lambda type.

Bug Fix: Fixed a bug in the logic for inferring the type of list expressions when the expected type is "object".

Bug Fix: Improved handling of bidirectional inference for call expressions when the expected type contains a union of literals and the function returns a generic type.

Enhancement: Added new check for a common source of bugs where an equals operator within an if statement compares two values whose literal types do not overlap and will therefore never evaluate to True.

Bug Fix: Fixed bug in handling of "Final" type annotation with no specified type argument (e.g. "x: Final = 4").

Enhancement: Added support for inferring type of subscripted tuple when subscript is a negative integer literal.

Bug Fix: Fixed recent regression where `super(A, self).x` did not return an unknown type if class `A` had a class in its MRO that had an unknown type.

Bug Fix: Allow lowercase `tuple` type to be subscripted in versions of Python prior to 3.9 if it is within a quoted annotation.

Bug Fix: Fixed false positive error due to constraint solver's handling of a TypeVar used within a Callable parameter that is matched to a function parameter annotated with another TypeVar.

Enhancement: Improved handling of literals within constraint solver when used with bidirectional type inference.

Bug Fix: Fixed bug that caused false positive error when a generic call expression was used for an argument to an overloaded function and TypeVar matching errors were reported.

Enhancement: Deferred resolution of metaclass during class type resolution to improve compatibility with code generated by mypy-protobuf, which contains cyclical dependencies.

Bug Fix: Fixed bug in declaration provider that caused declaration of class variables to not be resolved correctly when accessed via a `cls` parameter in a class method.

Bug Fix: Fixed bug in symbol resolution when a local class mirrors the name of a class in typing (e.g. `List`) but is not imported from typing and is used in a context where it is forward declared without quotes.

Bug Fix (from pylance): Avoid recursing infinitely when searching for source files when there is a cyclical symlink present.

Bug Fix: Fixed type inference for "yield" expressions. The previous code was using the same logic for "yield" and "yield from".

Enhancement: Added check to determine if type variables in generic protocols use the appropriate variance.

Performance Improvement: Limited "implied else type narrowing" to expressions that have declared types. It's too expensive to infer types.