v0.74.0

Likely to cause new Flow errors:

• Flow now performs exactness checks that were previously skipped in some cases (e.g when $ObjMap is used on an exact type).

New Features:

• Significant progress towards supporting the LSP (Language Server Protocol) natively.
• Allow custom module resolvers (experimental, only works with the haste resolver system).
• Flow lints for unnecessary optional chaining.

Notable bug fixes:

• Allow autocomplete to work with optional chaining.
• Only report status as GCing when actually GCing.

Misc:

• Improve the args used when launching child processes to give more information about the process when you run ps.
• Add a max_literal_length option to .flowconfig which replaces a magic constant.
• Multi-hop (indirect) find-refs now supports class instances.
• Revamp find-refs on ES6 named exports to improve reliability.
• Allow internal slot properties to be optional.
• Improve shutdown of the server monitor process.
• Try to gracefully stop server process when monitor exits.
• Print server status updates on new lines when Flow is not called from a tty.
• Add additional properties to the react-dom/server libdef.
• Add 'as' property to the HTMLLinkElement libdef.
• Add a libdef for the Asynchronous Clipboard API.
• Update libdef for Clients.matchAll to return an Array rather than an Iterator.

Parser:

• Rename InterfaceType to InterfaceTypeAnnotation.