facebook/flow v0.311.0

on GitHub

New Features:

• Added support for string and number literal properties in declare class and interface

Library Definitions:

• Change the Record<K, T> utility type's key bound from K: string to K: PropertyKey, allowing number and symbol keys in addition to string
• Added some TS built-in types that were missing from Flow's core lib

Misc:

• When experimental.allow_variance_keywords is set to true, we support the keywords in / out / readonly along with +/- for variance