perf(ci): halve CI wall clock by parallelizing jobs and caching gems

[matthv]

Why

CI grew slow as datasources were added: 50 jobs, ~52 min of runner time, ~3 min 10 wall clock. Per-job breakdown from run 33058967442 showed no slow job — the cost was job count plus uncached bundle install eating ~60% of every job.

	Before	After
Jobs	50	27
Runner minutes	~52 min	~13 min
Wall clock	~3 min 10	~1 min

What changed

Lint: 26 jobs → 1. A single root .rubocop.yml governs the monorepo, so one bundle exec rubocop already lints all 840 files across the 13 packages — the packages matrix ran the identical command 13× per Ruby version. The per-package bundle install was dead weight on top: bundle exec at the root restricts activation to the root Gemfile, so rubocop never saw those gems anyway. TargetRubyVersion: 3.0 pins the parser, so the ruby-version dimension couldn't change the result either.

Verified against a pristine BUNDLE_PATH holding the root Gemfile alone — rails, sqlite3, mongoid, activerecord all absent from the load path, rubocop still exits 0 over all 840 files.

The unixODBC step goes with it (it only existed to build ruby-odbc for the snowflake bundle); it is retained in the test job, which still needs it.

Lint and test now run in parallel. They are independent; chaining them made the critical path the sum rather than the max. deploy now lists lint explicitly, since it previously depended on lint only transitively through test — without that, a release could ship with RuboCop red.

Gem caching on the shared BUNDLE_PATH, keyed on Gemfiles/gemspecs rather than the gitignored lockfiles. The test key names only its own package's Gemfile-test so a one-package PR doesn't miss on all 24 cells, while keeping every gemspec, since path: deps mean a sibling's gemspec still affects resolution.

CLAUDE.md — the scaffolding checklist pointed at the lint matrix this PR deletes.

Review notes

Verified and cleared: hashFiles degenerating to an empty key (all patterns match real files); a restored cache serving stale gems (impossible — no committed lockfiles, so bundler re-resolves every run and /tmp/bundle is only an artifact store); deploy publishing without lint/test green (the if: carries no status function, so implicit needs gating holds); the qlty/ruby-version coupling (untouched); notify-ci-failure.yml (keys off the workflow name). Branch protection on main has no required status checks, so collapsing the 26 Lint (x, y) contexts into one cannot wedge PRs.

One accepted regression: no job resolves packages/*/Gemfile any more — the test job installs Gemfile-test, a different file in 11 of 13 packages. An unresolvable package Gemfile now goes green. Accepted because the signal covered 3 of 13 packages by accident of an inconsistency, tested a dependency edge absent from the published gemspecs (none of those three declares a forest_admin runtime dep), and never exercised PR code. A deliberate release-time install smoke test is the right home for that question.

Follow-ups (not blocking, both pre-existing)

• zendesk, mambu_payments and graphql_hasura declare siblings without path: in their Gemfile, unlike the other 10 — so bundle install in those packages resolves published siblings rather than the working tree.
• forest_admin_test_toolkit is published to RubyGems but has no specs, no Gemfile-test, and now no CI entry at all.

🤖 Generated with Claude Code

Note

Parallelize CI jobs and cache gems to halve wall clock time

• Removes the per-package and per-Ruby matrix from the lint job in build.yml; lint now runs once with Ruby 4.0 and a shared gem cache
• Adds gem caching to the test job keyed by OS, Ruby version, package, and Gemfile hashes, restoring to /tmp/bundle": "- Adds gem caching to the test job keyed by OS, Ruby version, package, and Gemfile hashes, restoring to /tmp/bundle
• Decouples the test job from lint by removing needs: [lint], and adds lint as a required dependency for deploy
• Updates CLAUDE.md to reflect that packages no longer need to be added to a lint matrix; clarifies test and coverage matrix conventions
• Risk: deploy now blocks on lint completing — if lint fails, deploy will not run even if coverage passes

^{Macroscope summarized 1c78eb1.}

[qltysh]

Coverage Impact

⬆️ Merging this pull request will increase total coverage on main by 0.1%.

🚦 See full report on Qlty Cloud »

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