Configurable JSON backend

[kirillkaiumov]

Currently faraday provides a middleware to encode/decode JSON payloads. Internally it uses json that from the Ruby's standard library. If I want to use another JSON backend like oj then I need to implement my own middleware. So, I have a few questions:

1. Do you think it's a good idea to allow configuring the built-in middleware to work with different JSON backends?
2. If I want to make my own middleware to use oj, can I make it inherit from Faraday::Response::Json class? Or it's considered "private" and better to inherit from Faraday::Middleware?

Thanks!

[olleolleolle]

👋 I turned this from an Issue into a Discussion, as this seemed more appropriate. Hope this helps!

[yykamei]

I think it's OK to inherit another middleware as Faraday Multipart does.

https://github.com/lostisland/faraday-multipart/blob/a3609a6921cd032252a9cee5d1388982e54bc045/lib/faraday/multipart/middleware.rb#L8

Also, I think it makes sense with the first solution. For example, Faraday's built-in Logger middleware has an option to receive a user-specified logger here.

faraday/lib/faraday/response/logger.rb

Line 15 in 36916f0

logger ||= ::Logger.new($stdout)

I prefer the first one, but it seems to require a lot of work for it.

[iMacTia]

Thank you @yykamei, this pretty much resonates with my view as well 🙌!

[iMacTia]

I just want to add to @yykamei answer a few thoughts at the maintainer:

• json is a standard gem, and thus we know it's always available. Using oj would require adding it as a dependency, or have some weird runtime check like if defined?(Oj) ... else .... Faraday 2.0 was all about moving away from external dependencies, so I'd much rather prefer a specialised middleware instead.
• It's perfectly fine to inherit from Faraday::Response::Json and override the parse method. If the fact that the method is private is causing issues, we can make it public/protected instead

[iMacTia]

FYI -- a gem already exists to do this, but it's based off the old JSON middleware included with faraday_middleware, so it will probably need an update, or you can use that as inspiration and build a new one 😄!

If you do, feel free to add it to awesome-faraday so people know it exists 🙌

[iMacTia]

@kirillkaiumov I'm happy to say a contribution was just merged that makes JSON encoders/decoders configurable, which I believe is what you were after 😄
#1539

I'll release it soon in a new minor version 👍