Pyright

Bug Fix: Fixed false positive error in constructor method with an input parameter annotated with a class-scoped TypeVar and with a default value.

Enhancement: Improved performance of type analysis for certain code patterns that involve inferred types of variables that are used in deeply nested loops and chains of updates. In one such example, this change reduced the analysis time from ~17000ms to ~200ms.

Bug Fix: Fixed bug in the handling of the `owner` parameter for the `__get__` method in a descriptor class. The type evaluator was using an `Any` type rather than the proper class type in this case.

Bug Fix: Updated TypeVar constraint solver so it tracks a "narrow bound" and "wide bound" for each TypeVar as they are being solved. This fixes several subtle bugs.

Enhancement: Updated typeshed stubs to the latest.

Behavior Change: Added new top-level "extraPaths" config option for pythonconfig.json that specifies the default extraPaths to use when no execution environments apply to a file. Changed settings logic to use the new default extraPaths mechanism for the "python.analysis.extraPaths" setting.

Bug Fix: Fixed bug related to the handling of `from . import X` statement located in a file other than `__init__.py`. When used outside of an `__init__.py` file, this import looks for the `__init__.py` and imports the requested symbol `X` from it rather than looking for a submodule `X`.

Enhancement: Improved completion provider's handling of method overrides so it properly handles properties.

Enhancement (from pylance): Add lowercased items from `__all__` in auto-imports.

Bug Fix: Fixed bug in constraint solver that occurs when a constrained TypeVar is used in conjunction with a protocol that has a contravariant TypeVar.

Bug Fix: Fixed a bug that generated a false positive error when a function (or other callable) was assigned to a Hashable protocol.

Enhancement (from pylance): Made auto-imports lazy for better completion suggestion performance.

Enhancement (from pylance): Improved readability of hover text for functions and methods with overloaded signatures.

Bug Fix: Fixed false positive error when using an instance or class variable defined within a Protocol class within a method in that same class. The previous logic was based on a misinterpretation of a sentence in PEP 544.

Bug Fix: Fixed false positive error in type checker when dealing with two types that are both unions and both contain constrained type variables.

Bug Fix: Fixed improper handling of symlinks used in editable installs. This affected auto-import functionality.

Bug Fix: Fixed recent regression that caused crash in hover provider.

Bug Fix (from pylance): Fixed issue that caused editable installs to require a restart of the language server before their effects were visible.

Bug Fix: Fixed false positive error during TypeVar constraint solving in the case where the same TypeVar is used in both the form T and Type[T] in the same signature.

Enhancement: Improved support for enums. The Python spec indicates that attributes that start and end with an underscore are not treated as enum members, nor are attributes that are assigned a descriptor object.

Enhancement: Added support for inferring the "value" and "name" fields of an enum.

Bug Fix: Added support for unparenthesized pattern subject lists in match statement.

Bug Fix: Fixed false positive error related to a type alias declared within a class.

Bug Fix: Fixed type evaluation bug that resulted in the incorrect inference of an exception type within an "except X as Y" clause when the expression X was a bound TypeVar.

Enhancement: Improved detection and error reporting for class definitions that depend on themselves (illegal cyclical dependency). Previously, pyright failed in ways that were difficult to diagnose.

Enhancement: Added support for symbolic links in import resolver both for resolution of ".pth" files and for imports themselves.

Behavior Change: Removed support for "venv" entry in execution environments since this never really worked. Clarified in documentation that import resolution within an execution environment is not transitive.

Bug Fix: Fixed bug in completion provider that caused class variables not be included as suggestions as members for the "cls" parameter in a class method.

Enhancement: Added error check for access to non-required fields in a TypedDict using a subscript with a literal string field name. Added support for "narrowing" of a TypedDict class based on guard expression of the form "S in D" where S is a string literal name of a non-required field. Improved the synthesized "get" method on a TypedDict for non-required fields; it now returns an Optional[T] (where T is the defined type for that field) rather than just T.

Enhancement: Updated to the latest typeshed stubs.

Enhancement: Added error check for a "yield" or "yield from" statement used within a list comprehension. This generates a runtime syntax error.

Bug Fix: Fixed bug in type inference for value returned by a "yield" or "yield from" statement.

Bug Fix: Fixed bug in type evaluator that caused some diagnostics to be suppressed unintentionally and in a non-deterministic manner (based on the order in which types were evaluated).

Enhancement: Added a heuristic to disable the "implied else" analysis if the code is within a function that has no input parameter annotations. This mitigates the performance overhead of "implied else narrowing".

Enhancement: When a function decorator is applied and the decorator returns a function that has no docstring, copy the docstring from the decorated function.

Enhancement: Changed inference logic for constructors to allow synthesized type for `cls` to retain its generic form when instantiated, so the expression `cls()` will remain generic.

Bug Fix: Fixed false positive "metaclass conflict" error that occurs when the metaclass has an unknown class type in its class hierarchy.

Bug Fix: Fixed bug in type evaluator when dealing with a bound TypeVar. The constraint solver wasn't properly handling the Type[T] statement in all cases.

Bug Fix: Fixed recent regression in CLI where partial stub packages were not applied correctly.

Enhancement: Eliminate duplicate python search paths, eliminating the need to search the same path more than once on every import resolution.

Bug Fix: Fixed crash in logic that handles partial type stub merging. The crash occurs when a search path points to a file (e.g. a zip file) rather than a directory.

Enhancement: Added support in PEP 646 when the unpacked TypeVarTuple is not at the end of the type parameter list. This allows for suffixing when matching type arguments against type parameters and when matching TypeVarTuple parameters in a Callable.

Enhancement: Added better error reporting for reveal_type and reveal_locals calls.

Enhancement: Added file system caching to import resolver for performance reasons.

Bug Fix: Fixed bug in type-printing logic for tuples. When typeCheckingMode is "off", type arguments are supposed to be displayed if they are not all "Any" or "Unknown", but they were omitted always.

Bug Fix: Fixed bug that caused type evaluation behavior that depends on (including, possibly, false positive errors) when evaluating subexpressions within a case statement.

Enhancement (from Pylance): Fix HTML escaping in code blocks.

Behavior Change: Exempt ParamSpec from "single use of TypeVar within function signature" check.

Enhancement: Improved error reporting for ParamSpec misuse.

Bug Fix: Fixed bug in logic that verifies exception type in "raise" statement. It was not properly handling generic types that were bound to BaseException.

New Feature: Add --ignoreexternal CLI flag for use with --verifytypes feature. (Contribution by Vlad Emelianov)

Enhancement: The --verifytypes output now includes file paths in the report. (Contribution by Vlad Emelianov)

Bug FIx: Fixed crash that occurred when a function was declared within a local scope but when the function's symbol was previous declared "global" or "nonlocal" within that scope.

Enhancement (from Pylance): Method and class docstrings now inherit from parent classes if docstrings are missing in child class.

Enhancement (from Pylance): Improved support for partial stubs (where py.typed file includes "partial" as per PEP 561).

Bug Fix: Fixed bug that caused incorrect type evaluation for member access expressions when the member was a descriptor object and the base type was a variable containing a reference to the class.

Bug Fix: Fixed bug in document symbol provider that caused incorrect range to be returned for classes and functions.

Enhancement: Improved tracking of incomplete types (those that have not yet been fully established because of recursive type dependencies within the code flow graph).

New Feature: Added logic for if/elif chains that contain no else clause but completely narrow one or more variables.

Behavior Change: Changed behavior of TypeVar constraint solver to eliminate literal types (widening them to their associated type) when solving for TypeVars, unless a literal type was explicitly provided (e.g. using explicit specialization like `List[Literal[1, 2, 3]]`).

Behavior Change: Changed reportOverlappingOverload to be an error in strict mode.

Bug Fix: Fixed bug in logic that determines whether one callable type can be assigned to another. It wasn't taking into account the positional-only parameter separator (`/`).

Bug Fix: Fixed a bug in conditional type narrowing that narrows based on descriminated member variable types. It was being over aggressive in narrowing in the negative ("else") case when the type of the member was a union of literal types.

Bug Fix: Fixed false positive error that occurred when setting or deleting the member of an object where that member's type is defined by a parent class and is generic but is specialized by a child class.

Enhancement: Extended check that detects redeclared functions and methods to also report redeclared properties within a class.

Bug Fix: Fixed crash in parser that occurs when malformed index expression is parsed.

Enhancement: Improved error message for certain type incompatibilities.

Bug Fix: Fixed bug in logic that determines whether a function type is assignable to another function type. It was not properly handling the case where the destination had a **kwargs parameter and the source had an unmatched keyword parameter.

Enhancement: Added new check to ensure that the type signature of a function with overloads is the superset of all of its overload signatures.

Enhancement: Improved consistency of error messages by standardizing on "incompatible" rather than "not compatible".

Bug Fix: Fixed bug in handling of `type(x)` call that resulted in false positive errors.

Behavior Change: Changed the logic that determines whether a variable assignment is an implicit type alias definition. If there is an explicit type annotation (other than the use of the PEP 612 TypeAlias), it is no longer considered a type alias. This is consistent with the rules mypy uses.

Bug Fix: Fixed a bug in the logic for inferring "cls" parameter that resulted in incorrect type evaluations.

Enhancement: Added check to detect inappropriate use of variables (that are not type aliases) within type annotations.

Bug Fix: Fixed bug in type compatibility logic that permitted a type of `Type[Any]` to be assigned to type `None`.

New Feature: Implemented support for PEP 655: Marking individual TypedDict items as required or potentially-missing. This PEP is still under development, so the spec could change.