Likely to cause new Flow errors:
- Some new errors might be raised when using
React.cloneElementwith polymorphic components. Eg. try-Flow. Note that React.cloneElement is deprecated - Nested
declare moduleis no longer a parser error, but a type checking error declare moduleis now explicitly banned in nested scope and outside of library definition files. It already does nothing under those contexts.
New Features:
- All kinds of imports are now supported in library definition files
- We will no longer require annotations on class properties, if the class properties are already initialized with "annotation-like" expressions. e.g. We can now infer the type directly for properties like
prop = (foo: string): number => 3.
Notable bug fixes:
- Fixed a bug that causes the first run of
flow checkto always return 0 errors, when some parts of temporary directory is a symlink. - Hover type on react elements now show the type of the component and props, instead of just
React$Element. (e.g. try-Flow) - For missing annotation on exports, we now correctly say some annotation is missing on an identifier instead of array pattern. e.g. for
export function f(a) {}, we now say "Missing type annotation at identifier" instead of "Missing type annotation at array pattern".
Parser:
- Flow can now parse
declare namespace Foo {...}statements. The body of the declare namespace statement shares the same restrictions ofdeclare module. - Invalid exports in
declare moduleare no longer parse errors. They are now type checker errors.