v0.55.0
Likely to cause new Flow errors:
- Fixed a bug that caused unsoundness with
$ObjMap
.
New Features:
- Flow is now capable of servicing some requests while it is rechecking. This should improve the IDE experience on large codebases.
- Added $Call utility type.
- Added $Compose and $ComposeReverse utility types.
- Added support for spreading
mixed
into an object type.
Notable bug fixes:
- Improve results from the find-refs command.
- Allow null and undefined as React.createElement() config (fixes #4658).
Misc:
- Miscellaneous code cleanup.
- Located error messages related to functions at only the signature, rather than the entire range of the function body.
- Improved error messages when
this
types are incompatible. - Properly check subtype relationships between callable objects.
- Fixed a bug that caused
mixed
not to be properly printed fromtype-at-pos
. - Improved error messages regarding incompatible Array type parameters.
- Preserve some inference information across module boundaries.
- Support assignments to shorthand method properties in object literals.
Typedefs:
- Added captureStream() to HTMLCanvasElement and HTMLMediaElement.
- Added HTMLOptGroupElement return type for document.createElement().
- Added Recoverable and context to the
repl
module. - Fixed return type for AudioContext.createMediaStreamDestination().
Parser:
- Various fixes to improve test262 compliance:
- Correctly disallowed various illegal constructs in destructuring patterns.
- Allow destructuring in
catch
. - Added \u2028 and \u2029 to the list of line terminators.
- Allow unicode escape codes in identifiers.
- Improved parse errors when using private properties outside of classes.
- Disallowed reserved words as function param names in types (e.g.
(switch: number) => void
).