Remove direct struct subclassing

[bdewater]

Description

This is a follow-up to #1489 - I noticed I was still missing Faraday::Request#body= from Tapioca's generated definitions.

Since it also overrides #[] and #[]= it was impossible to set Struct members, so refactored this to a PORO that mostly (but not exactly) looks like the struct it used to be.
Edit: aliased the original member getter/setters so we can override #[] and #[]=. This retains methods inherited from Struct people might be relying on (like #== which is tested in Faraday via Marshal dump/load).

Also did Faraday::Adapter::Test::Stub while I was here for consistency.

[olleolleolle]

@bdewater Thanks for adding the context of the change, that makes a lot of sense.

[yykamei]

member_get doesn't seem to be used in this file. Is it still necessary?

[bdewater]

This is a leftover from an earlier iteration, it could be removed.

[iMacTia]

Good point. I'll merge this as-is and cleanup in my other PR 👍

[yykamei]

Maybe, I understood why member_set is required. Previously, Request inherited an anonymous class generated by Struct, but in this PR, it becomes just a Struct and cannot use super. Is it correct?

As far as I see, #params= and #headers= don't follow the documentation: " Replace params, preserving the existing hash type." In other words, their implementations are different from their documents. I think they don't have to be explicitly declared by overriding themselves. What about simply removing #params= and #headers= and delegating the functionalities to Struct? Struct has "#attribute=" out of the box.

[bdewater]

You are correct for why I added member_set :)

I believe the docs for #params= and #headers= are correct. Normally you don't build a Request directly but use methods on Faraday::Connection. Connection builds Utils::ParamsHash and Utils::Headers (both subclasses of Hash) in the initializer and passes these to Faraday::Request.create. If you merge in additional params or headers (probably using a regular Hash) like this:

connection.get do |req|
  request.headers = { foo: "bar" }
end

this code ensures headers stays a Utils::Headers instance (and does things like stringifying the key) instead of becoming a regular Hash with symbol keys.

Removing these overridden setters leads to one (not very clear) test failure on this line:

faraday/spec/faraday/connection_spec.rb

Line 744 in 2477fe2

expect(req.params['b']).to eq('b')

  1) Faraday::Connection request params with url and extra params allows to override all params
     Failure/Error: expect(req.params['b']).to eq('b')
     
       expected: "b"
            got: nil
     
       (compared using ==)

[olleolleolle]

Thank you both for adding even more context to this detail!

[iMacTia]

Thank you @bdewater, and sorry if this struct is a mess 🙄.
Can't wait to get rid of them in v3.0 🙌!

[yykamei]

Thank you! That's a great explanation 👍 The document seems to be good because it says "preserving the existing hash type".

So, member_set is aliased as Struct's original #[]= before it is overridden.

faraday/lib/faraday/request.rb

Lines 96 to 98 in 2477fe2

	def []=(key, value)
	headers[key] = value
	end

LGTM