Pyright

Enhancement (from Pylance): Improvements to completion provider and signature help provider.

Bug Fix: Allow `TypeAlias` to be used prior to Python 3.10 if imported from typing_extensions.

Enhancement: Added special-case handling for magic method `__class_getitem__`, which is implicitly a classmethod.

Enhancement: Added support for classes that include the `__class_getitem__` magic method to provide custom behaviors for subscripting.

Enhancement: Support detecting multiple site-packages directories in venvs. [Contribution by Truls Asheim]

Bug Fix: Fixed bug that caused incorrect type errors when dealing with magic methods on the tuple class.

Bug Fix: Fixed a confusing diagnostic message relating to incorrect method override.

Enhancement: Enforced that TypeVars being solved for in a TypeVar map match the expected scope.

Bug Fix: Fixed bug in synthesized `setdefault` method on TypedDict for required entries, which never use the default value.

Bug Fix: Fixed bug that resulted in an inappropriate error when a kwarg parameter was typed with a class-defined TypeVar (e.g. `**kwargs: _VT`).

Bug Fix: Made the check less strict for the use of covariant type vars within a function input parameter annotation. In particular, unions that contain covariant type vars are now permitted.

Enhancement: Add __future__ module as import suggestion. [Contribution by cdce8p]

Bug Fix: Fixed bug that caused the issubtype type narrowing logic to fail when used with a bound TypeVar T in combination with Type[T].

Bug Fix: Don't add suggestions for 'with Y as [ ]'. [Contribution by cdce8p]

Enhancement: Type aliases are now expanded in completion provider text in the same way as the hover text. [Contribution by cdce8p]

Enhancement: Improve handling of type aliases for auto-import. [Contribution by cdce8p]

Behavior Change: Changed diagnostic about first argument to `super` call to be part of the reportGeneralTypeIssues diagnostic rule so it is suppressed when type checking mode is set to "off".

Bug Fix: Fixed bug that caused code within finally clause to be marked as unreachable if there was no except clause and the code within the try block always raised an exception.

Bug Fix: Fixed bugs in ParamSpec logic. It was not properly handling the case where the target callable type contained keyword-only or positional-only parameter separators.

Bug Fix: Added support for `tuple` and `type` subscripts when `__future__` annotations is defined.

Bug Fix: Fixed bug that caused improper errors when using new-style union syntax with `from __future__ import annotations`.

Bug Fix: Worked around a reported bug in node 14+ on Linux where calls to fs.watch throw an exception when creating a recursive file watcher. The workaround is to catch the exception and proceed without a file watcher in place.

Enhancement: Updated typeshed stubs to the latest.

Bug Fix: Fixed parser crash when an f-string contained an empty expression.

Bug Fix: Fixed bug that caused diagnostics with "information" severity to be reported as "warnings" in the CLI version of pyright.

Bug Fix: Fixed recent regression in handling type evaluations for "and" and "or" operators. Short-circuiting evaluation was not handled correctly in some cases.

Bug Fix: Fixed bug in parser that caused expressions within f-strings to be handled incorrectly if they contained syntax errors.

Bug Fix: Fixed bug in parsing of annotated variable assignments. It was not allowing yield expressions on the right-hand side.

Enhancement: Added special-case logic to handle `isinstance` call when the first argument is a TypedDict and the second argument is a `dict` class. A TypedDict does not derive from `dict` from the perspective of type checking, but at runtime, `isinstance` returns True. This affects both type narrowing logic and checks for unnecessary `isinstance` calls.

Bug Fix: Fixed bug in type narrowing logic for expressions of the form "type(x) is y" or "type(x) is not y". The logic was incorrectly narrowing the type in the negative ("else") case. And in the positive case, it was not properly handling cases where x was a subclass of y.

Bug Fix: Fixed bug that caused completion suggestions to be presented when typing a period within a comment on the first line of the file.

Enhancement: Improved signature help for data classes where default values are specified.

Bug Fix: Fixed bug in NamedTuple logic that caused spurious errors when attempting to assign a NamedTuple to a Tuple with a compatible set of type arguments.

Bug Fix: Fixed bug in perf optimization for set, list, and dictionary type inference. The old code was failing to evaluate expressions associated with entries beyond 64, which meant that tokens were not classified correctly and type errors in these expressions were not reported.

Bug Fix: Do not report errors for union alternative syntax (PEP 604) if evaluation of type annotation is postponed (either in a quote or via PEP 563).

Bug Fix: Fixed bug that caused spurious errors when evaluating type annotations within certain circumstances.

Bug Fix: Fixed bug that sporadically caused incorrect and confusing type errors such as "list is incompatible with List".

Bug Fix: PEP 585 says that it should be possible to use `type` in place of `Type` within type annotations. Previously, this generated an error.

Behavior Change: Changed re-export logic for type stub and py.typed modules to honor the clarification that was recently added to PEP 484. Previously, any import that used an "as" clause was considered to be re-exported. Now, symbols are re-exported only if the "as" clause is redundant (i.e. it is of the form `import A as A` or `from A import X as X`).

Bug Fix: Fixed inconsistency in handling of imported symbols that have multiple untyped declarations within the target module. The inconsistency was between the two cases `import x, x.y` and `from x import y`. In the latter case the type resolution logic considered only the last symbol declaration in the target module, but in the former case it was considering all declarations and returning the union of all types.

Bug Fix: Fixed bug in f-string parsing. It was generating an error for comma-separate list of expressions, which is legal.

Bug Fix: Fixed inconsistency in type narrowing for `isinstance` and `issubclass` calls. Previously, the narrowing logic used the target class(es) if the source expression was of type Any but did not do the same when the source expression was a union type that included Any but all other subtypes were eliminated.

Bug Fix: Added logic for `or` and `and` operators to handle the case where the left-hand operand is always falsy (in the case of `or`) or always truthy (in the case of `and`).

Bug Fix: Fixed internal error that occurs when the type evaluator encounters a circular dependency between a class decorator and the class that it decorates.

Bug Fix: Fixed bug in protocol matching logic that results in incorrect errors indicating a function type mismatch.

Perf Improvement: Conditionalized the logic for the reportPropertyTypeMismatch diagnostic check. It's somewhat expensive, so don't bother executing it if it's disabled.

Perf Improvement: Fixed performance regression introduced along with user-defined type guards.

Enhancement: Added support for reverse logical operators (`__ror__`, `__rand__`, etc.).

Bug Fix: Added code to handle the case where a class has a custom metaclass that handles logical or (the `__or__` method). Previous to this change, use of an `|` operator with classes was assumed to be a misuse of PEP 614 in Python versions prior to 3.10.

Bug Fix: Fixed bug that resulted in an incorrect error when a list comprehension expression was used within a lambda and the expression referenced one or more of the lambda parameters.

Bug Fix: Fixed bug that caused incorrect error to be reported for names referenced in global and nonlocal statements when those names were not declared in the outer scope.

Bug Fix: Fixed bug that resulted in incorrect error when second argument of isinstance was a "type" or "Type" object.

Bug Fix: Fixed bug in parser that caused incorrect errors in chains of comparison or "in"/"not in" operators. The expression "a == b == c" should be parsed as "a == (b == c)", but the code was previously parsing it as "(a == b) == c". This didn't matter in most cases, but it does when the types of a, b and c differ.

Bug Fix: Fixed bug that resulted in incorrect errors when an instance variable with no type declaration was assigned an enum value. It was assumed to be of that literal enum value type rather than the wider enum type.

Bug Fix: Fixed bug that resulted in false positive error when a class derived from another class that was instantiated from a custom metaclass.

Bug Fix: Fixed bug that caused type errors when internal type cache was cleared. The code previously used parse node IDs to distinguish between types that are not created via class declarations (NamedTuple, type, NewType, etc.). Since node IDs change when a file is reparsed (due to a change), these IDs cannot be relied upon for type comparisons.

Enhancement: Added support for "typing" module aliases when checking for TYPE_CHECKING symbol in static boolean expressions.

Behavior Change: Removed recently-added "reportInvalidTypeVarUse" diagnostic rule and associated checks. After further discussion, we decided that there are legitimate cases where a TypeVar can appear only once in a function signature.