HTTParty response cache is broken

[seanneale]

Rails 6.0.5.1
Ruby 2.7.6

We have recently upgraded HTTParty to v0.20.0 and found that the cached response is missing some information from the response.request:

• last_uri
• raw_request
• last_response

We require raw_request for our logging, so have reverted to v0.19.1

Scripts to reproduce the issue:

1. Script closer to the root cause

url = "https://avatars.githubusercontent.com/u/12815721?s=200&v=4"
r = HTTParty.get(url);nil
r.request.raw_body
# => nil
Marshal.load(Marshal.dump(r)).request.raw_body
# expected: nil
# actual: NoMethodError (undefined method `body' for nil:NilClass)

2. Script closer to our scenario

# Enable cache in the local
make bash-devel
rails dev:cache
bin/rails c

url = "https://avatars.githubusercontent.com/u/12815721?s=200&v=4"
​
# set cache
r_2 = Rails.cache.fetch("sean_test", expires_in: 5.minutes, race_condition_ttl: 5, force: true) do
  r = HTTParty.get(url)
end
​
# test if body available (it will be)
r_2.request.raw_body
​
# fetch cache
r_2_cache = Rails.cache.fetch("sean_test", expires_in: 5.minutes, race_condition_ttl: 5) do
  HTTParty.get(url)
end; nil
​
# test if body available (it won't be)
r_2_cache.request.raw_body

[jnunemaker]

This seems related to #714 by @baberthal.

I have a fix in #767.

I think the best thing is to serialize all the ivars and then re-initialize them but this should at least solve this issue and not cause backwards compat issues (hopefully).

@seanneale That said, I would not recommend digging into internals like you are. One of the things you are accessing is just an ivar which if not given a method should really be treated as private. I'll think on that PR and see if anything else should go in. Should be able to merge soonish.