New Features:
- The deprecated
*type is now an alias toany. You can useflow codemod replace-existentials, which is available in previous versions of Flow, to upgrade your codebase to not use*. This codemod command will not be available in the current or future versions of Flow. - Add (experimental) codemod to annotate variables that cause constrained write errors in future Flow versions.
- Add (experimental) codemod rename variable names that are reused with different types.
- Add --include-comments and --include-locs flags to the
flow astcommand. - Add $ObjMapConst<O, T> builtin type, alias for $ObjMap<O, () => T>.
Notable bug fixes:
- Fix bug in
$KeyMirrorso that it respects the optionality of its arguments. - Type
JSONas object rather than a class. This prevents code such asnew JSON()which is a runtime error.
Library Definitions:
- Add
InputEvent.dataTransfer - Declare
AggregateErrorclass - fixes #8764 (thanks @lachlanhunt). - Improve
UIEvent,InputEventandKeyboardEventtypes.
Misc:
- Fix typo in CONTRIBUTING.md (thanks @jereef).
- Clarify comments for ConcretizeTypeAppsT logic after Subtyping_kit refactor (thanks gnprice).
Parser:
- Fix a bug that allowed comments after the
#in private identifiers.