fix: Retry flags requests on 502 and 504

[marandaneto]

Summary

• retry remote /flags/?v=2 evaluations on HTTP 502 and 504 using feature_flag_request_max_retries
• keep status-code retries opt-in to the flags evaluation request path only
• add focused specs for 502/504 retry, non-retry statuses, and max-retries opt-out

Testing

• ruby -c lib/posthog/feature_flags.rb
• bundle exec rspec spec/posthog/flags_spec.rb
• bundle exec rubocop lib/posthog/feature_flags.rb spec/posthog/flags_spec.rb

[greptile-apps]

Comments Outside Diff (1)

1. spec/posthog/flags_spec.rb, line 342-352 (link)

   Missing exhaustion test for status-code retries at higher retry counts

   The set to a higher count context (max_retries = 3) tests exception-retry exhaustion (4 HTTP calls → re-raises), but there is no parallel test verifying that 502/504 status-code retries also exhaust correctly — i.e., that when 502 occurs on every attempt the method eventually returns the 502 response and stops after max_retries + 1 calls. Without this test, a regression where status-code retries loop indefinitely or bail out early would go undetected.

   Rule Used: When implementing retry logic, include comprehensi... (source)

   Learned From
   PostHog/posthog#32651

   Note: If this suggestion doesn't match your team's coding style, reply to this and let me know. I'll remember it for next time!

_{Reviews (1): Last reviewed commit: "fix: Retry flags requests on 502 and 504" | Re-trigger Greptile}

[marandaneto]

Closing in favor of #209, which contains the same changes from a branch in the PostHog/posthog-ruby repository instead of a fork.