New Features:
- Added support for string and number literal properties in
declare classandinterface
Library Definitions:
- Change the
Record<K, T>utility type's key bound fromK: stringtoK: PropertyKey, allowingnumberandsymbolkeys in addition tostring - Added some TS built-in types that were missing from Flow's core lib
Misc:
- When
experimental.allow_variance_keywordsis set totrue, we support the keywordsin/out/readonlyalong with+/-for variance