Pyright

Bug Fix: Fixed bug that could lead to an internal stack overflow when a generic value was used as an argument for a function or class decorator.

Enhancement: Added support in literal comparison type narrowing to filter out comparisons to "None" in positive case.

Bug Fix: Fixed bug in parser where it was too permissive in allowing keywords to be used as identifiers. The Python interpreter is less permissive, so pyright's parser should match.

Bug Fix: Fixed several bugs that caused crashes (dereference of undefined variable) in certain circumstances.

Enhancement: Added a new log error for the case where enumeration of files within the workspace is taking longer than 10 seconds.

Bug Fix: Fixed bug in tokenizer which treated 'constructor' as a keyword.

Bug Fix: Fixed bug in "type(x) is y" type narrowing logic to handle the case where x is an instance of a generic class.

Enhancement: Added check for illegal trailing comma in "from x import y," statement. This generates a syntax error at runtime.

Enhancement: Added check for illegal use of "Protocol" as a type argument.

Enhancement: Implemented new check for a class that is decorated with `final` but does not implement all abstract methods from abstract classes that it derives from.

Enhancement: Added check for inappropriate use of `ClassVar` that will generate runtime exceptions.

Enhancement: Added logic to enforce protocol mismatches if a member in the protocol is marked "Final" and the class is not (or vice versa).

Behavior Change: Modified assignment type narrowing for index expressions so it applies only to built-in types. This eliminates incorrect type inference when using a class that has assymetric `__setitem__` and `__getitem__` methods.

Enhancement: Fixed false positive error when `property` is combined with `functools.cache`.

Bug Fix: Fixed handling of generic type aliases with missing type arguments used in type annotations when the type alias itself is a member access expression.

Enhancement: Added new diagnostic check (controlled by the existing "reportUnsupportedDunderAll" config switch) that reports an issue with a name specified in `__all__` if that symbol does not exist at the module level.

Enhancement: Updated typeshed stubs to latest version.

Enhancement: Added support for nested callables that use a ParamSpec at each level.

Bug Fix: Fixed false positive error related to the use of the `Final` keyword when annotating attributes within a dataclass.

Bug Fix: Fixed bug in TypeVar matching logic that allowed Type[T] to be matched against an instance of a type.

Behavior Change: Changed type checking logic for functions to allow a function with a return result of `NoReturn` to match against any other return type.

Bug Fix: Fixed false positive error in parser dealing with f-strings with string literals within the f-string expression that, in turn, have quotes within the string literal.

Enhancement: Added support for "attribute docstrings" (defined in PEP 258) in completion provider.

Bug Fix: Fixed bug in type analyzer related to a TypeVar with a bound type that is a union.

Bug Fix: Fixed false positive error when calling an object that has an `Any` in its inheritance chain.

Enhancement: Improved support for `callable` type narrowing in cases where the type is a non-callable instance, but a subtype could be callable.

Enhancement: Improved handling of `callable` type narrowing when the type involves a constrained type variable.

Enhancement: Added support for ParamSpec's within a Protocol, which is supported in Python 3.10.

Enhancement: Improved handling of `isinstance` type narrowing logic when the type being narrowed is a callable.

Bug Fix: Fixed recent regression in type evaluator that occurs when a generic (non-specialized) type is assigned to another generic type and the type parameter(s) for the generic type are invariant.

Bug Fix: Fixed bug that caused diagnostics from an open file not to be cleared after closing that file if it was not saved.

Enhancement (from pylance): Improved completion suggestions for literals when used as dictionary keys.

New Feature: Implemented "reportUninitializedInstanceVariable" diagnostic check that looks for instance variables that are not initialized in the class body or constructor.

Bug Fix: Fixed false positive error due to bug in constraint solver related to the handling of `Type[T]` when `T` is a constrained type variable.

Bug Fix: Fixed false positive error related to the use of a recursive type alias when `from __future__ import annotations` was in effect.

Bug Fix: Fixed false negative related to augmented assignment expressions when operand was a union type and a subset of the union subtypes were not supported for the operation.

Bug Fix: Fixed false positive error related to member access of optional type.

Bug Fix: Fixed false positive error related to an escape sequence (backslash) used in an f-string format specifier.

Bug Fix: Fixed false positive error with f-string format specifier that contains an expression within braces and also a colon specifier.

Enhancement: Updated typeshed stubs to latest version.

Bug Fix: Fixed false positive error when evaluating a subscript (index) operation with an index value that is a union type and an overloaded `__getitem__` method that requires union expansion.

Enhancement: Added new check for a function overload that contains an implementation.

Enhancement: Added special-case handling for addition of two tuples that have known lengths.

Bug Fix: Fixed bug in check that detects improper variance for type variables used within generic protocols. Class or instance variables within a generic protocol must use invariant type variables.

Enhancement: Improved heuristics for type matching when source and dest types are unions and invariance is being enforced — specifically in the case where the destination union type includes generic types.

Bug Fix: Fixed recent regression that resulted in false positive errors when a class declaration used both `Type[X]` and `X` in its specialization of base classes.

Bug Fix: Fixed false positive error related to `isinstance` narrowing of a non-constrained TypeVar.

Bug Fix: Changed encoding of literals in error messages to avoid including raw (unescaped) special characters in output.

Behavior Change: Increased maximum source file size from 16MB to 32MB.

Enhancement: Improved formatting of error messages that include expressions — specifically when the expression includes an empty dict ("{}").

Bug Fix: Fixed false positive error for the case where a function with positional/keyword parameters is assigned to a callback protocol that accepts only keyword parameters.

Enhancement: Added support for member access expressions for the `None` object.

Enhancement: Added support for `isinstance` and `issubclass` type narrowing where the variable type and the test type have no apparent relationship. The type evaluator synthesizes a class that is a subclass of both types — effectively an "intersection" of the two.

Behavior Change: Modified `reportUnnecessaryIsInstance` diagnostic to never report always-false conditions because the type checker no longer generates such conditions.

Removed support for undocumented "mspythonconfig.json" config file name. This was previously available as an alternative to "pyrightconfig.json", but we've decided to standardize on the latter.

Bug Fix: Changed logic for "overload missing implementation" check to not require an implementation within a protocol class.

Enhancement: Updated typeshed stubs to latest version.

Bug Fix: Fixed confusing error message when file or directory is specified on command line but is excluded by the "exclude" section of the config file.

Behavior Change: Exempt classes from `__slots__` check if they explicitly declare an empty slots. This is commonly used for mix-in classes that are compatible with slotted classes.

Internal Change: This version of pyright includes a significant change within the type evaluator that simplifies the code and eliminates a major source of bugs related to the handling of `Type[X]` type annotations.