I had the same dream... so I started using Flow[0]! Put all of my codebase in &#x2F;* @flow weak *&#x2F; to start, then slowly tightened it up with more type hints, declarations, etc.<p>[0] <a href="http:&#x2F;&#x2F;flowtype.org&#x2F;" rel="nofollow">http:&#x2F;&#x2F;flowtype.org&#x2F;</a>