• Improved exhaustiveness checking in switch statements.
• Improved autocomplete results to show documentation in more cases.
• Turned the untyped-type-import lint into an error by default. In a later release, we will turn this into a regular type error instead of a lint error.
• Removed esproposal configuration options from the .flowconfig format.
• Added library definition for MediaRecorder API.
• Fixed Object.freeze to no longer incorrectly convert an inexact object into an exact object.
• Fixed handling of exported objects with spreads in types-first mode.