@facebook-github-bot facebook-github-bot released this Nov 27, 2018 · 187 commits to master since this release

Assets 7

Likely to cause new Flow errors:

  • Fixed an error in the React.createRef definition. Refs are for any type of value,
    not just React elements.

New Features:

  • Added support for subcommands to the CLI and a flow config find command that
    finds the .flowconfig governing path.

Notable bug fixes:

  • Fixed file_sig for deep destructured requires.
  • Fixed a stack overflow in the flow ls --json command.
  • Fixed a crash when the module reference prefix is used on an untyped module.


  • Removed the flow port command.
  • Various improvements to the AST differ.
  • Made progress in shifting from concrete to abstracting locations, by
    • functorizing a number of modules over their use of locations, and
    • updating the core typechecking logic to operate solely on structures containing
      abstract locations.
  • Removed the redundant Expression.Member.computed field from the AST.
  • Allow configuring path to node in runtests.sh.
  • Refactored JSX.frag_closingElement of the AST to not be an option.
  • Fixed error localization in import type and import typeof with default.
  • Added the location of function signatures to the AST.
  • Removed prototype members when autocompleting JSX props.
  • Cleaned-up handling of the mixed case from LookupT.
  • Optimized the case of enumerations when used as keys.

Library definition changes:

  • Made geolocation PositionOptions optional.
  • Added flow definitions for React hooks.
  • Added a calculateChangedBits parameter to the React.createContext definition.
  • Added React.ConcurrentMode and React.StrictMode definitions.
  • Added React.lazy and React.memo definitions.


  • Refactored flowconfig option parsing into a list of parsers.