Regression from #65: circular-require warning when cookie_jar is required before cookie (1.1.6)

[lineoffligbot]

Summary

The fix for #65 (shipped in 1.1.6) resolves the warning for isolated loads of http/cookie or http/cookie_jar, but introduces the same warning in a different scenario: loading http/cookie_jar before http/cookie.

Minimal reproduction

$ ruby --version
ruby 4.0.1 (...) [x86_64-darwin25]
$ gem list http-cookie
http-cookie (1.1.6)
$ ruby -w -e 'require "http/cookie_jar"; require "http/cookie"'
warning: loading in progress, circular require considered harmful -
  .../http-cookie-1.1.6/lib/http/cookie.rb
warning: Expected http/cookie to define HTTP::Cookie but it didn't

Why the 1.1.6 fix doesn't cover this

• Before 1.1.6: cookie_jar.rb did require "http/cookie" eagerly, so loading cookie_jar first would fully load cookie before returning. No warning in this path.
• After 1.1.6 (commit 93bf8de): cookie_jar.rb now does module HTTP; autoload :Cookie, "http/cookie"; end. The eager require is gone, so only the autoload registration persists.
• When http/cookie is then required, cookie.rb:3 requires http/cookie/version, and version.rb:2 opens class Cookie inside module HTTP. Ruby resolves the Cookie constant, finds the registered autoload, and fires it for the still-loading http/cookie.rb — circular require warning.

Real-world impact

The http gem (>= 5) triggers this because lib/http.rb loads http/session before http/response:

• http/session.rb:5 — require "http/cookie_jar" (registers the autoload)
• http/response.rb:11 — require "http/cookie" (triggers it)

So any require "http" under -w / Ruby 4.0 prints the warning.

Suggested direction

Defining HTTP::Cookie (even as an empty shell) at the top of cookie.rb before require 'http/cookie/version' would satisfy the autoload without cycling. Alternatively, moving the VERSION constant out of a class-reopen (e.g. assigning HTTP::Cookie::VERSION after the class is defined) sidesteps the constant lookup during load. Happy to send a PR if there's agreement on the approach.