Accept job arg in SolidQueueAdapter#stopping? for Rails 8.2 compatibility

[Micaherb]

Summary

CI is failing on main and in PRs. This PR fixes the deterministic rails_main CI failure, where every job in the matrix fails with:

ContinuationTest#test_continuable_job_completes [test/integration/continuation_test.rb:28]:
Expected false to be truthy.

Root cause

Rails commit 6d1c401d (landed on rails/rails@main 2026-05-26, target version 8.2.0.alpha) — "Pass job instance to stopping?" — changed ActiveJob::Continuable#checkpoint! to call:

queue_adapter.stopping?(self)

instead of queue_adapter.stopping?. The upstream CHANGELOG explicitly requires every adapter to migrate:

Queue adapters that implement stopping? must accept the job as an optional positional argument, i.e. def stopping?(job = nil), in order to work with this version and older versions of Rails.

SolidQueueAdapter was relying on the no-arg stopping? predicate generated by class_attribute :stopping. Against Rails main every checkpoint! call raised ArgumentError, the continuable job errored out before completing, and the test asserted unfinished jobs were still present after the 5 s wait.

Fix

Define stopping?(job = nil) explicitly on the adapter. The optional positional arg keeps the method compatible with:

• Rails 7.1 / 7.2 / 8.0 / 8.1 — call with no args, default nil is used
• Rails 8.2+ — call with the job, currently unused

The job parameter is intentionally not consumed yet — this adapter doesn't support per-job interrupt reasons. That's a separate enhancement (Rails 8.2 also allows returning a custom reason; we just return false / true as before).

Test plan

• CI green across the full appraisal matrix, including all rails_main jobs (which were failing 9/9 before this fix)
• No regression on rails_7_1 / 7_2 / 8_0 / 8_1 (the new signature is backwards compatible)
• PR Bump Rails to 7.2.3.1 for Active Support / Action View security advisories #7 (Rails 7.2.3.1 security bump) can rebase on top of this once merged and get a clean CI run

Linked

Unblocks #7.

[jpcamara]

Good catch - I'd rather see this stay as a PR though and point at that as you upgrade to 8.2, since it's gotta end up in solid queue proper very soon i'd imagine. someone has a PR opened a few days ago rails#747