Every Linux lane that does real work ran on a 4-core `ubuntu-latest`. The
Python suite and the JS checks were split into many small jobs to make that
size usable. Each split job repeated the full setup. In most of the JS jobs
the repeated setup cost more than the work.
The work lanes move to larger runners. Then the splits that existed only to
make small runners usable go away.
Python tests: 12 slices become 1 job on a 96-core runner. Slicing cost a
matrix job, a duration cache, a per-slice artifact and a merge job. 96 cores
clear the floor that the slowest single test file sets, which is about 82s. A
second slice divides work that is already at that floor, and adds a second
setup. Duration data from run 32522943054 gives the numbers behind this: 3178
files, 11645s in series.
The worker count is explicit, because `run_tests.sh` defaults to twice the
core count. A later commit sets it from a measurement on this hardware.
JS checks: 14 jobs become 1. The matrix paid about 371s of repeated setup to
spread about 612s of work. One larger runner installs one time. The three UI
shard scripts and `run-ui-shard.mjs` are therefore removed, because the
unsharded `test:ui` covers the same tests.
The unit of parallel work inside that job is a CHECK, and not a workspace.
apps/desktop is most of the payload, and its own `check` is a serial && chain.
A spread across workspaces alone therefore leaves that chain as the long pole.
A package that declares `check:*` sub-scripts gives one unit for each
sub-script. That is the same selection rule the matrix used.
The loop lives in `.github/scripts/run-workspace-checks.mjs`, so the same
sequence runs on a laptop. It runs 11 units together, buffers the output of
each one, and fails at the end with the full list. Children that share one
stdout interleave their lines and make a failure hard to read.
`npm run --ws check` stops at the first workspace that fails.
`check:test:plugins` joins the desktop `check` script. The matrix prefers
`check:*` sub-scripts over the plain `check` script, so `check:test:plugins`
ran only as its own leg. Without this change the merge drops that suite and
the job stays green.
node_modules is cached on the lockfile, and `npm ci` is skipped on an exact
hit. The `cache: npm` option of `setup-node` caches only the ~/.npm tarball
cache, which leaves the extract and the postinstalls to pay again.
The arm64 image build stays on a native arm64 runner. A build of linux/arm64
on an x64 host uses emulation.
The docker test lane caps its workers at the core count. Each of those tests
drives a container, so the docker daemon sets the limit and not the processor.
`.github/actionlint.yaml` declares the runner labels. actionlint knows the
GitHub-hosted labels only, and an undeclared label reads as an error that
hides the real findings.
The `detect` job checks out one file through a sparse checkout, and its
timeout drops to 1 minute. It reads
`scripts/ci/classify_changes.py` and nothing else.
Verification:
- actionlint reports 9 findings across all workflows. An unmodified HEAD with
the same config reports the same 9. This change adds none.
- A wrong label still fails. actionlint reports `ubuntu-latest-32-cor` and
`ubuntu-latest-32-arm-cores`.
- Every changed workflow parses, and `name` parses as a string.
- A replay of the `save-durations` merge step against a three-artifact layout
returns all 3178 entries.
- An expansion of the npm script graph gives the same leaf commands for the
parallel units and for a plain `npm run check`, in both directions. Against
the 13-leg matrix the count is 13 to 11, and the whole difference is the
three UI shards that collapse into one unsharded `check:test:ui`.
- `--list` reports the 11 units, and a full local run completes and reports
the time of each unit.
- The runner labels cannot be verified here. The first real run is the test.
