Pyright

Bug Fix: Fixed bug that caused the recently-added "discriminated field type narrowing" to be used in cases where it should not. This resulted in types being narrowed inappropriately when a field was typed as a union of literals.

Behavior Change: Changed command-line version to not print any non-JSON output when "--outputjson" option is used.

Behavior Change: Changed behavior when "useLibraryCodeForTypes" is set to "false". Previously, all ".py" library code was ignored in this case. Now, ".py" types are used for types if the package has an associated "py.typed" file as specified in PEP 561. Packages with no "py.typed" file will still be ignored if "useLibraryCodeForTypes" is "false".

Bug Fix: Fixed a couple of bugs that resulted in the hover text incorrectly identifying a symbol as a "type alias".

Behavior Change: Changed type inference logic to use "List", "Set", and "Dict" rather than "list", "set" and "dict" when inferring the type of a list, set or dict expression. These are aliases for the same underlying class, but the upper-case versions are more consistent with type annotations used within the code.

Bug Fix: Fixed "NoReturn" inference logic for async functions. This logic was previously flagging the code after a call to such a function as unreachable.

Enhancement: Improved parser to detect syntax errors involving unpack operator within a comprehension.

Enhancement: Changed import resolution logic to allow binaries (e.g. ".so" files) to satisfy local imports (within the package), not just third-party imports (within site-packages).

Enhancement: Extended bidirectional type inference (expected types) to list comprehensions.

New Feature: Added new diagnostic rule "reportPropertyTypeMismatch" that verifies that the type of the input parameter to a property's setter is assignable to the return type of the getter.

Bug Fix: Fixed bug that caused a crash in the type checker in cases where type arguments were not provided to a few special-case built-in classes.

Bug Fix: Fixed a bug in the handling of generics that involve constrained TypeVars. The TypeVar matching logic was sometimes inappropriately specializing the type using the first constrained type.

Bug Fix: Added special-case handling in type checker for callers who request the type of an expression that happens to be a name used in a call expression to designate a named parameter. This isn't really an expression, so the code wasn't handling it correctly, but callers (such as the hover provider and the new semantic token provider) were assuming that it was safe. This resulted in incorrect "X is not defined" diagnostics being logged.

Enhancement: Improved completion suggestion behavior when the insertion point is between an identifier and an empty index (e.g. "f[]") or in the presence of a missing right square bracket (e.g. "f.[").

Behavior Change: Changed diagnostic related to type argument count to be controlled by the "reportGeneralTypeIssues" diagnostic rule. It was previously always emitted as an error.

From Pylance: Fix progress reporter type, auto-import/symbol changes, worker thread updates, improve auto-import tooltips (977)

Enhancement: Updated typeshed stubs to the latest version.

Bug Fix: Eliminated incorrect error when "super()" was used in a class where one or more parent classes were of an unknown type.

Bug Fix: Changed the handling of old-style comment method annotations to accept an optional annotation for "self" and "cls" parameters.

Bug Fix: Changed handling of dataclass classes that derive from a class whose type is unknown. The synthesized constructor now allows any parameter list in this case.

Enhancement: Improved completion provider to distinguish properties from other methods.

Behavior Change: Changed heuristics for function return type inference so methods that raise a NotImplementedError and have no other return path have an inferred return type of Unknown rather than NoReturn. Such methods should be marked as abstract, but frequently they are not.

Behavior Change: Changed the behavior of the import resolution logic to fail an import resolution of a multi-part name (e.g. "a.b.c") if it can't be fully resolved. This could produce false positives in cases where third-party libraries are using dynamic tricks to manipulate their package namespace, but it will eliminate false negatives.

Bug Fix: Suppress the use of "Unnecessary" diagnostic hints (used to display variables and code blocks in gray) if the LSP client claims not to support this tag.

Enhancement: Added new "reportMissingTypeArgument" diagnostic rule and enabled it by default in "strict" mode. It generates a diagnostic when a generic class or generic type alias is used in an annotation with no type arguments provided.

Bug Fix: Fixed handling of scopes for nested classes. The previous logic allowed an inner class to access variables defined in an outer class, which is not permitted.

Enhancement: Added check for raise statements that take an exception class but the class constructor requires one or more arguments.

Bug Fix: Fixed bug in tokenizer that cause line numbers to be off when an invalid token occurred at the end of a line.

Bug Fix: Fixed a bug in the Pyright parser. It was not correctly following the Python grammar spec when parsing type annotations, so it generated syntax errors in some cases where that was inappropriate.

Enhancement: Added a check and a general type diagnostic for metaclass conflicts.

Bug Fix: Fixed bug in command-line version that caused an error to be reported when "useLibraryCodeForTypes" or "verboseOutput" was specified in the pyrightconfig.json file.

Enhancement: Added support for protocol matching where the protocol includes an overloaded method.

Enhancement: Improved diagnostic messages for function type mismatches.

Enhancement: Improved diagnostic messages for tuple matching and union assignments.

Enhancement: Changed nested diagnostic messages to use non-breaking spaces so indentations are visible within the VS Code "Problems" panel.

Bug Fix: Fixed bug in reportIncompatibleMethodOverride diagnostic check. The logic was checking for wider parameter types when it should have been checking for narrower.

Bug Fix: Fixed bug in method override validation code. It wasn't applying partial specialization of the base class, resulting in inappropriate errors in some cases.

Bug Fix: Fixed bug in the type evaluation of expressions with + or - operators and integer literal operands. These expressions should evaluate to a literal type, not an int.

Bug Fix: Fixed bug in parsing of f-strings that contain \N escape and a Unicode character name that includes a hyphen.

Bug Fix: Fixed bug in type evaluator that caused an incorrect error when a class decorator was used for a generic class.

Bug Fix: (From Pylance) Fixed performance problem related to file change events triggered by reads from site-packages.

Enhancement: Enabled support for PEP 613 (TypeAlias).

Bug Fix: Fixed bug that caused type aliases to get expanded in some contexts when they shouldn't.

Bug Fix: Fixed bug that caused "from .A import *" to work incorrectly when the wildcard included symbol A.

Enhancement: Added logic in completion provider to return class variables in base classes when the insertion point is in the context of a subclass body.

Bug Fix: Fixed TypeAlias code to check for Python 3.10 rather than 3.9 since PEP 613 has been moved out to 3.10.

Enhancement: Added performance optimization for TypedDict classes. Entries are now computed once and cached in the class type. This provides a big speed-up for TypeDict classes that have a large number of fields.

Enhancement: Added performance optimization for union types that contain large numbers of string literals. The code for inserting new items into a union is O(n^2); this optimization makes it O(n) for string literal types.

Bug Fix: Fixed bug that caused custom import aliases of "Final", "Literal" and "TypeAlias" to not work correctly.

Bug Fix: Fixed bug that resulted in spurious errors when hovering over module names in import statements.

Bug Fix: Fixed several bugs relating to symbols introduced into a class by its metaclass.

Bug Fix: Fixed bug that caused type analyzer to crash when a nonlocal binding referred to a symbol that was not present in an outer scope and then was assigned to.

Bug Fix: Fixed regression that caused "isinstance(x, Callable)" to be flagged as an error when PEP 484 says that it's legal.

Enhancement: Changed error messages related to "partially unknown" types to expand type aliases, which can obscure the unknown part of the type.

Enhancement: Added support for narrowing types based on the pattern "A.B == <literal>" and "A.B != <literal>" when A has a union type and all members of the union have a field "B" with a declared literal type that discriminates one sub-type from another.

Enhancement: Added bidirectional type inference for ternary expressions.

Bug Fix: Fixed incorrect handling of member accesses when the accessed field had a type that was a union between two or more classes, some with special accessor methods (e.g. "__get__") and some without.

Enhancement: Improved type checking for assignments of callable types. Previously, certain edge cases were ignored.

Enhancement: Added code to check for overlapping (obscured) overload functions.

Bug Fix: Fixed bug that caused incorrect evaluation of type alias that refers to Literal types. The literal values were being stripped in some cases.

Bug Fix: Fixed recent regression that caused type aliases that described literal types to be printed incorrectly in hover text and error messages.

Enhancement: Added code to report overloads that overlap in an "unsafe" way — i.e. they can potentially accept the same arguments but return different (incompatible) types.

Enhancement: Updated typeshed stubs to latest version.

Bug Fix: Fixed bug in assignment checks between homogeneous multi-length tuples and fixed-size tuples.

Enhancement: Diagnostic rule severity overrides are now editable in the VS Code settings UI.

Bug Fix: Fixed out-of-memory error that occurred during a workspace "find symbols" operation. We were not properly checking for the heap high watermark during this operation.

Enhancement: Added support for special type "Counter" exported by typing module, which is an alias for collections.Counter.

Bug Fix: Fixed bug in bidirectional type inference for dictionary statements. The logic was not allowing for dict subclass Mapping.

Enhancement: Improved type checker's handling of "in" operator. It previously flagged an error if the right operand didn't support a `__contains__` method. It now properly checks for iterable types as well.

Bug Fix: Fixed bug that caused incorrect evaluation of symbol types within a chain of assignments (e.g. "a = b = c = 4") in some cases.

Enhancement: Enabled file watcher for libraries to detect changes in installed packages. This behavior is already standard for Pylance, but it was disabled for Pyright.

Enhancement: Improved handling of Tuple type. The type checker now does a better job retaining the types of the individual elements within a Tuple or a class that derives from a Tuple.

Enhancement: Improved support for NamedTuple classes and classed derived from NamedTuple. The type checker now retains types of individual elements when used with unpacking and indexing operators.

Behavior Change: Changed "find workspace symbols" to return only symbols from within user code or opened files, not library files that are closed.

Bug Fix: Fixed recent regression that caused incorrect errors to be generated in sub files for certain call expressions.

New Feature: Added support for Concatenate as described in latest version of PEP 612. Added ParamSpec and Concatenate to typing.pyi.

Bug Fix: Fixed bug in the handling of unrecognized escape sequences within string literals.

Bug Fix: Fixed bug related to a subtle interaction between bidirectional type inference of list expressions that contain literal values and TypeVar matching. The previous logic was incorrectly matching T in List[T] and the list contained a literal type. It should have stripped the literal if possible.

Enhancement: Added diagnostic message for TypeVar with a single constraint type for consistency with mypy.

Enhancement: Added support for member access completion suggestions when the LHS is a function or a None type.

Behavior Change: Behavior change for type stub generator: don't emit `__all__` assignments or assignments to self.xxx in function bodies. These violate PEP 484 guidelines for type stubs.

Enhancement: Added diagnostic check to reportInvalidStubStatement that flags parameter default value expressions that are not "..." in stub files.

Bug Fix: Fixed bug that caused annotated types of vargs and kwargs parameters not to be printed in hover text.

Enhancement: Implemented support for older-style function annotation type comments. I previously resisted adding this additional complexity, but we're seeing many libraries that still contain these annotations for backward compatibility with Python 2.

Bug Fix: Fixed bug that caused a crash in the type analyzer when a protocol class referred to itself.

Enhancement: Added support for "useLibraryCodeForTypes" option in config file. It overrides the client setting of the same name or the "--lib" command-line option.

Bug Fix: Fixed several bugs in logging for config errors.

Enhancement: Added logic to type checker to validate that the "self" or "cls" parameter with a specified type annotation is assignable when binding the method to an object or class.

Enhancement: Improved type assignment diagnostic message. Added "(property)" designator to the end of a property type to differentiate it from a normal attribute.

Enhancement: Added code to validate that method overloads are all abstract or not.

Enhancement: Updated typeshed stubs to the latest.