Pyright

New Feature: Types are now validated for assignments that target objects with a `__set__` method, including properties with setters.
New Feature: Added key/value type inference for dictionary literal statements.
New Feature: Unreachable code is now detected in cases where a return or raise occurs before the end of a code block.
New Feature: Added verbose diagnostic information for import resolution failures. Added `--verbose` switch for command-line tool.
New Feature: Type constraint subsystem is now able to handle more complicated code flow inferences.
Bug Fix: Fixed false positive error related to arg/param matching when an unpacked arg is used.

New Feature: Added type constraint for assert command.
Bug Fix: Fixed bug in parser that allowed an arbitrary number of comma-separated expressions to appear after an assert keyword.
Bug Fix 90: Fixed false error for common arithmetic binary operators that act upon int/float/complex when operand is union with an unknown or any type.
Bug Fix 88: Text completion options shouldn't appear for comments or strings.
Bug Fix: Fixed regression introduced in previous version where the check for max import chain length generated false positives.
Bug Fix: Command-line tool didn't allow the use of "--watch" with a list of specified files.
Bug Fix 89: Fixed regression in tokenizer that caused incorrect line attributes when CR/LF was contained within a string.

New Feature: Improved formatting of errors and warnings for command-line tool.
New Feature: Started to implement type completion for keywords, local variables, module variables, and class/instance variables.
Bug Fix: FIx for 83: Changed the way type analyzer handles assignment statements with type annotation.
Bug Fix: Fix 85, recursion crash due to long import chains.
Bug Fix: Partial fix for 82 (hang)
Bug Fix: Don't flag invalid as errors string escape sequences in raw strings.
Bug Fix: Removed logo from VS Code README.

New Feature: Unused code blocks are now displayed as "grayed out" in VS Code.
New Feature: Use of "yield from" generates error for Python <3.3.
New Feature: Scanning of string literals now fully complies with Python spec, including support for all defined escape sequences.
New Feature: Added "reportInvalidStringEscapeSequence" config switch to control whether the analyzer reports errors or warnings for invalid escape sequences.
New Feature: Use of Protocol in a code file is now flagged as illegal for Python <3.7.
New Feature: An attempt to instantiate certain special classes defined in typing (Callable, Generic, etc.) now emits an error.
Fixed bug in import cycle detection logic that could result in slow analysis time and even an infinite loop.

New Feature: implemented proper type checking for assignments to variables with explicitly declared types.
New Feature: reportUntypedBaseClass enables reporting of base classes that are Unknown type and therefore defeat all type checking for derived types.
New Feature: reportOptionalContextManager enables reporting of Optional types used with "with" statements.
New Feature: reportOptionalOperand enables reporting of Optional types used within unary and binary statements where None is not otherwise permitted.
New Feature: more complete type checking for operand types for unary and binary statements.
New Feature: relaxed type checking of parameters to constructor of NamedTuple factory class if `<NTFactory>.__new__.__defaults__` is assigned a value at some point.
Bug Fix: Type[X] wasn't properly specialized in some cases.
Bug Fix: Literal byte strings (e.g. b'hello') are now properly typed as bytes rather than Unknown type.

New Feature: Added "reportOptionalIterable" config switch to allow reporting of Optional types used as iterables (e.g. in for statements).
New Feature: Added "reportImportCycles" config switch to report cycles in import graph.
New Feature: Added "reportPrivateUsage" config switch to report use of private variables and functions.
New Feature: Type checker now infers the types of list literals.
New Feature: Type checker now understands the unpack operator used within dictionaries, lists, and parameter lists.
New Feature: Type checker now validates types for slice operands.
New Feature: Type checker now understands `__getitem__`, `__setitem__`, and `__delitem__` magic operators and enforces their presence for subscripting.
Improved performance by restricting implicit imports when using "from X import Y" form of import statement.
Fixed some false positives in reporting of operator overrides for unary and binary operators.
Removed the assumption that "self" and "cls" are the first parameter names for instance and class methods.