Pyright

Behavior Change: Changed behavior of function overload evaluation to more closely match the behavior of other type checkers. Notably, if one or more argument have union types, they are expanded, and each combination of argument union subtypes can use different overloads.

Bug Fix: Fixed bug that caused false positive error when assigning a function with no position-only marker to a function with a position-only marker.

Enhancement: Added support for call arguments whose types are constrained type variables and must be constrained to a particular subtype during call evaluation because the LHS of the call imposes such constraints.

Enhancement: Added support for special cases of class pattern matching as described in PEP 634.

Enhancement: Added support for auto generation of `__match_args__` class variable for dataclass and named tuples.

Enhancement: Added support for type narrowing of the subject expression within a "match" statement based on the matched pattern.

Bug Fix: Fixed bug in type analyzer that resulted in a false positive error when a return type annotation included a generic class but omitted the type arguments.

Enhancement: Implemented first cut at generalized support for dataclass transforms.

Behavior Change: Allow NoReturn return type annotation for `__init__` method.

Bug Fix: Fixed bug in completion provider that resulted in no valid completion suggestions at the end of a "from x import a, " statement.

Bug Fix: Fixed bug in type checker that led to a false positive when assigning a function to a callable type and the source contained unannotated parameters.

Bug Fix: Fixed numerous bugs that result in occasional type evaluation errors, some of which appear to be somewhat non-deterministic.

Bug Fix: Fixed bug in type evaluator that caused incorrect type evaluation for annotated parameter types in some cases.

Bug Fix: Fixed a bug in the type checker that resulted in a false positive error when using "|" (union) operator in parameter type annotations in some cases.

Bug Fix: Changed binder logic for "from .a import x" statements in `__init__.py. Implicit import of ".a" is performed only in cases where there is a single dot. For example, "from .a.b import x" does not implicitly import ".a.b".

Bug Fix: Fixed bug that resulted in a false positive error within type checker when a constrained TypeVar was used in a lambda callback.

Bug Fix: Fixed bug in type variable constraint solver that resulted in false positive error in certain cases involving bidirectional type inference with unknown (or missing) type arguments.

Enhancement: Reduced memory consumption of tokenizer for string literal tokens.

Enhancement: Improved performance of type analyzer in cases where certain type checking diagnostic rules are disabled.

Enhancement: Improved startup time of pyright by eliminating redundant calls to Python interpreter to retrieve import resolution paths.

Behavior Change: Automatically mark parameters as accessed (so they don't appear as "grayed out") in the following circumstances: 1) it is a self parameter in an instance method, 2) it is a cls parameter in a class method, 3) it is a parameter in a method marked abstract, 4) it is a parameter in a method that is part of a protocol class, 5) it is a parameter in an overload signature.

Bug Fix: Fixed incompatibility with pypy when retrieving import resolution paths from the configured Python interpreter.

Enhancement: Added diagnostic for `__init__` method that does not have a return type of `None`.

Enhancement: Configuration settings can now be stored in a pyproject.toml file. If both pyproject.toml and pyrightconfig.json are both present, the latter takes precedent.

Bug Fix: Changed logic that detects generator functions to accommodate yield statements that are provably unreachable in the code flow.

Behavior Change: Changed dataclass logic to not enforce ordering of fields with defaults vs those without if `init=False` is specified.

Enhancement: Extended method override check to include dundered methods (other than constructors).

Bug Fix (from pylance): Removed duplicate "yield" suggestion in completion list.

Enhancement (from pylance): Improved logic that maps type stubs to corresponding source files.

Enhancement: Added support for implicit `__annotations__` symbol at the module level.

Enhancement: Updated to the latest typeshed stubs. Removed third-party stubs for that were marked as Python 2 only (enum34, fb303, futures, ipaddress, kazoo, openssl-python, pathlib2, pymssql, Routes, scribe, tornado).

Enhancement: Added support for `type(None)` within isinstance type narrowing.

Bug Fix: When providing a completion suggestion for an async method override, an "await" operator is now added in the generated return expression.

Bug Fix: Fixed false positive error in argument/parameter matching logic for function calls that occurs when a keyword argument targets a parameter that can be either positional or keyword and a spread operator is used in an earlier argument.

Bug Fix: Fixed bug that resulted in false positive error when a constrained TypeVar type was passed through the "isinstance" type narrowing logic and then used as an operand in a binary operation.

Bug Fix: Fixed several bugs that caused type checker crash in certain cases.

Bug Fix: Fixed bug in type narrowing logic when the narrowed expression contained an assignment expression (walrus operator). It was not properly narrowing the target of the assignment expression.

Bug Fix: Fixed bug in "isinstance" type narrowing support when the first argument is a type (e.g. a class or Type[T]) and the second argument is `type` (or a tuple that contains `type`).

Bug Fix: Fixed bug in "isinstance" type narrowing logic where it didn't properly handle protocol classes that support runtime checking.

Enhancement (from Pylance): Improved docstring formatting in hover text.

Behavior Change: Suppressed "access to non-required key" diagnostic if the access is performed within a try block.

Bug Fix: Fixed bug in 'callable' type narrowing logic. It wasn't properly handling type variables.

Enhancement: Implemented new diagnostic rule "reportUnnecessaryComparison". It checks for "==" and "!=" comparisons where the LHS and RHS types have no overlap and the LHS has no `__eq__` overload. This new diagnostic rule is off by default in normal type checking mode but is on in strict mode.

Bug Fix: Fixed false positive error that occurred when file started with "from typing import Collection". This was due to mishandling of a cyclical dependency in the typeshed classes.

Enhancement: Improved bidirectional type inference for expressions that involve the pattern `[<list elements>] * <expression>`.

Bug Fix: Fixed false positive error relating to the use of parentheses in "with" statement when using Python 3.9.

Bug Fix: Fixed bug in type evaluation of async functions that are not generators but have a declared return type of AsyncGenerator. The actual return type needs to be wrapped in a Coroutine in this case.

Bug Fix: Suppressed diagnostic check for `Subscript for class "X" will generate runtime exception` when it's used in a PEP 526-style variable type annotation. Apparently the exception occurs only when used in other contexts like parameter and return type annotations.

Enhancement: Added configuration option "strictSetInference" which is analogous to "strictListInference" and "strictDictionaryInference" but specifically for set expressions.

Enhancement: Tweaked heuristic in constraint solver to prefer types that have no "unknown" element to those that do.

Enhancement: Improved the handling of TypeVar matching when the source and dest types are both unions, the types are being compared with invariant constraints, and the dest contains a TypeVar.

Enhancement: Fixed misleading error message for "unsupported `__all__` operations".

Enhancement: Improved error message for dataclass fields.

Bug Fix: Fixed bug that caused inconsistent type evaluation for type annotations based on order of evaluation. It was triggered in some cases by the semantic highlighting feature.

Bug Fix: Fixed bug in the function type compatibility logic. If the source has a `*args` or `**kwargs` parameter but the dest does not, the function should still be assignable.

Behavior Change: Changed the logic that searches for a config file. It currently searches from the current working directory all the way up the folder hierarchy. This makes sense only for a command-line tool, not for a language server. The latter already knows the project root, and we should look only in that directory for a config file.

Bug Fix: Fixed bug in signature help provider where its heuristics were causing it to return a bad response when the insertion point was immediately after a comma and a call expression preceded the comma.

Bug Fix: Added support for an import edge case where a module's `__init__.py` file is apparently importing from itself but intends instead to import from one of its submodules.

Bug Fix: Fixed bug in namespace import resolution. When there are multiple import search matches, the import resolver needs to take into account the individual symbols specified in the import statement.

Bug Fix: Fixed a bug whereby call expressions within a type annotation were flagged as errors but not evaluated, which meant that symbols referenced within them were not marked as accessed.

Enhancement: Updated typeshed stubs to the latest.