Backwards incompatible change from 3.8.x -> 3.9.x

[mikestanley]

What version of protobuf and what language are you using?
Version: 3.8.1 & 3.9.1
Language: Ruby

What operating system (Linux, Windows, ...) and version?
N/A

What runtime / compiler are you using (e.g., python version or gcc version)
N/A

What did you do?

Upgrading from 3.8.1 to 3.9.1 Ruby library breaks compatibility.
Specifically this commit - 565154a

to_hash was dropped (since it really is a duplicate of the more common to_h) . However, there are implications to removing this method.

For example, Rails as_json method looks for to_hash (not to_h).
https://apidock.com/rails/Object/as_json

I consider this a backwards incompatible API change in a minor version upgrade.

[TeBoring]

#6166
Seems the removal was intentional. And they were aware of the breakage.

[haberman]

Sorry for the breakage, the existing behavior was arguably broken and I think it should be easy to simulate the old behavior with something like:

# Add to_hash to MessageExts, which is included in every message instance.
module Google
  module Protobuf
    module MessageExts
      def to_hash
        self.to_h
      end
    end
  end
end