Who
I kept running time cmd-a; time cmd-b and then arguing with myself about whether the second one won because it was faster, or because the first one warmed the cache and the tree had drifted.
For operators comparing formatters and linters who refuse that lie. Especially anyone already typing vp exec biome format --write next to vp exec oxlint and wanting the median, not the vibes.
What
I built compare, public michaelmonetized/compare. Bash. VERSION="0.1.0". bin/compare is 825 lines at HEAD (468 on init). install.sh drops it in /usr/local/bin (or $PREFIX). HEAD c5dbcd6. 3 commits. 0 stars. CLI only. No LICENSE. No release tag.
The product is git isolation for shell A/B:
- If the working tree is dirty, commit
compare: snapshot before benchmark(with--no-verify). - Force-create
compare/<slug-a>andcompare/<slug-b>from that shared SHA. - Checkout A, run command A
-ntimes withTIMEFORMAT, append to the log; blank line; same for B. - Restore the original branch. Leave the snapshot and
compare/*branches for inspection; delete them yourself.
Log lines look like POSIX time:
vp exec biome lint --write 1.36s user 0.36s system 151% cpu 1.134 total
vp exec oxlint --write 0.21s user 0.18s system 73% cpu 0.528 total
Default path: ../tests/compare-<cwd>-<c1>-<c2>-<UTCstamp>.log. Flags: -n, -c, -o, -g/--graph, --md. Subcommands: compare graph <log>, compare report <log>. Graphs: user / system / CPU% / total (blue A, yellow B). --md writes tables + mermaid and opens mdr (else open / xdg-open). Commands go through eval (trusted only).
Smoke on the pack box: compare "sleep 0.05" "sleep 0.12" -n 3 totals ~0.051 vs ~0.121, branches compare/sleep-0-05 and compare/sleep-0-12 left behind. README caveats remain honest: no CPU pinning, mutating commands can diverge branches, one intentional variable is on you.
Residue: plans/README.md still says the repo had no commits and no source code (docs-only improve plans). Those four plans are marked DONE. compare report is in --help and code; it is not in the README Contents. Second nightly (c5dbcd6) shares the exact tree with the first nightly (empty HEAD commit).
Where
Code: github.com/michaelmonetized/compare, public, branch main. No homepage. No live web demo. Clone + ./install.sh (or PREFIX=$HOME/.local ./install.sh).
Audience sits next to biome, oxlint, Vite Plus, and anyone who already treats time output as courtroom evidence.
When
2026-06-17, 6:57 AM Eastern. 217d4ac init: README, 468-line CLI, install script, four docs plans.
2026-06-22, 5:40 PM Eastern. b4fea7b nightly: CLI grows to 825 lines; README gains --md / mdr / CPU chart.
2026-06-22, 6:17 PM Eastern. c5dbcd6 nightly: same tree as b4fea7b. HEAD. Empty.
Why
Back-to-back time is a shared-state measurement pretending to be a tool measurement. A snapshot commit plus two named branches is the smallest honest isolator I would actually run. biome-vs-oxlint needs a log file outside the working tree, not another Slack debate.
Engagement Q: When you A/B two CLIs, what is the one variable you pretend you controlled, and which dirty-tree / warm-cache factor actually won?