ci: gate PR benchmark job behind a benchmark-relevant paths filter

[alejoamiras]

Problem

The benchmark / Benchmark job takes ~35 minutes and runs on every PR — docs-only changes included. It only produces meaningful output when something that affects compiled contracts or the benchmark harness changed.

Change

A changes job (dorny/paths-filter, SHA-pinned to the verified v3.0.2 commit) gates benchmark at the job level. It runs only when the PR touches:

Path	Why
src/**/*.nr	contract sources (gate counts)
**/Nargo.toml	workspace + per-contract manifests, aztec-nr git refs
benchmarks/**	the benchmark definitions
src/ts/test/utils.ts	every benchmark imports its setup helpers from here (verified: 6/6, and this file has no further local imports)
tsconfig.json	TS resolution config for the benchmark harness
package.json, yarn.lock	@aztec/* SDK + config.aztecVersion toolchain pins
.github/workflows/pr-checks.yml	the workflow itself

format and checks (JS/Noir tests) are deliberately untouched.

Pre-merge verification (all done — no reviewer legwork needed)

Case	Method	Result
Required-check trap (skip leaves a required context "Expected" forever)	GraphQL isRequired on live PR check contexts	✅ no status check is required on this repo, so the trap cannot trigger
Positive: workflow-file change → benchmark runs	this PR's own CI run	✅ Changes: success, benchmark / Benchmark ran
Positive: .nr contract change → benchmark runs	probe PR #31 (closed, run cancelled after verdict)	✅ benchmark / Benchmark started
Negative: docs-only change → skips	probe PR #29 (closed)	✅ benchmark: skipped, run concludes green
Negative: TS-test-body-only change → skips	probe PR #32 (closed, run cancelled after verdict)	✅ benchmark: skipped

Naming asymmetry to be aware of (matters only if checks are ever made required): when the job runs, the check is benchmark / Benchmark; when skipped, only benchmark exists. If benchmark should ever become a required check, that needs an always-run aggregate job evaluating needs results — happy to do as a follow-up.

Accepted trade-offs

• Stacked PRs: a skipped run uploads no benchmark-baseline-<branch> artifact, so a PR stacked on a skipped branch gets no baseline for its comparison (if_no_artifact_found: warn downstream — degrades gracefully, no stale-artifact fallback: the download action doesn't search older runs by default).
• Fail-open: if the changes job itself fails (rare — API outage), benchmark skips; the failed Changes check is a loud red X on the PR.
• Single-file helper entry: if benchmark setup helpers ever move out of src/ts/test/utils.ts, the filter must be updated in the same PR.

Review

Adversarially reviewed via a Codex loop (2 rounds): its confirmed finding (missing utils.ts/tsconfig.json) is incorporated; its stale-baseline concern was checked against the download action's source and retracted; final verdict was ship-as-draft. actionlint passes.

🤖 Generated with Claude Code

[github-actions]

Benchmark Comparison

CPU	Cores	RAM	Arch
AMD EPYC 9V74 80-Core Processor	4	16 GiB	x64

Contract: escrow

🚦	Function	Gates			DA Gas			L2 Gas			Proving Time (ms)
		Base	PR	Diff	Base	PR	Diff	Base	PR	Diff	Base	PR	Diff
⚪	(partial) withdraw	485,780	485,780		3,744	3,744		587,800	587,800		13,838	15,010	+1,172 (+8.5%)
⚪	withdraw	330,054	330,054		832	832		499,700	499,700		11,178	12,156	+978 (+8.7%)
⚪	withdraw_nft	378,231	378,231		1,440	1,440		527,400	527,400		12,313	13,338	+1,025 (+8.3%)

Contract: logic

🚦	Function	Gates			DA Gas			L2 Gas			Proving Time (ms)
		Base	PR	Diff	Base	PR	Diff	Base	PR	Diff	Base	PR	Diff
⚪	get_escrow	390,336	390,336		192	192		456,000	456,000		12,439	13,479	+1,040 (+8.4%)
⚪	secret_key_to_public_keys	387,695	387,695		192	192		456,000	456,000		12,459	13,481	+1,022 (+8.2%)
⚪	share_escrow	304,211	304,211		1,952	1,952		520,700	520,700		10,952	11,957	+1,005 (+9.2%)

Contract: multitoken

🚦	Function	Gates			DA Gas			L2 Gas			Proving Time (ms)
		Base	PR	Diff	Base	PR	Diff	Base	PR	Diff	Base	PR	Diff
⚪	burn_private	260,232	260,232		832	832		499,700	499,700		10,162	10,945	+783 (+7.7%)
⚪	burn_public	223,800	223,800		416	416		638,292	638,292		9,758	10,516	+758 (+7.8%)
⚪	initialize_transfer_commitment	225,054	225,054		768	768		474,500	474,500		9,690	10,557	+867 (+8.9%)
⚪	mint_to_private	297,795	297,795		1,408	1,408		511,400	511,400		10,932	11,829	+897 (+8.2%)
⚪	mint_to_public	223,800	223,800		416	416		637,800	637,800		9,657	10,510	+853 (+8.8%)
⚪	transfer_private_to_commitment	263,571	263,571		1,024	1,024		511,400	511,400		10,233	10,949	+716 (+7.0%)
⚪	transfer_private_to_private	336,124	336,124		2,048	2,048		555,100	555,100		11,350	12,343	+993 (+8.7%)
⚪	transfer_private_to_public	306,785	306,785		1,056	1,056		714,677	714,677		10,953	11,796	+843 (+7.7%)
⚪	transfer_public_to_commitment	223,800	223,800		640	640		663,516	663,516		9,772	10,506	+734 (+7.5%)
⚪	transfer_public_to_private	298,556	298,556		1,024	1,024		683,958	683,958		10,807	11,722	+915 (+8.5%)
⚪	transfer_public_to_public	223,800	223,800		480	480		673,505	673,505		9,690	10,509	+819 (+8.5%)

Contract: nft

🚦	Function	Gates			DA Gas			L2 Gas			Proving Time (ms)
		Base	PR	Diff	Base	PR	Diff	Base	PR	Diff	Base	PR	Diff
⚪	burn_private	275,232	275,232		416	416		661,052	661,052		10,545	11,397	+852 (+8.1%)
⚪	burn_public	223,800	223,800		448	448		670,034	670,034		9,681	10,489	+808 (+8.3%)
⚪	mint_to_private	341,272	341,272		1,600	1,600		735,342	735,342		11,468	12,447	+979 (+8.5%)
⚪	mint_to_public	223,800	223,800		448	448		670,718	670,718		9,684	10,499	+815 (+8.4%)
⚪	transfer_private_to_private	249,433	249,433		832	832		499,700	499,700		9,934	10,806	+872 (+8.8%)
⚪	transfer_private_to_public	275,261	275,261		416	416		659,258	659,258		10,665	11,419	+754 (+7.1%)
⚪	transfer_public_to_private	292,557	292,557		992	992		683,268	683,268		10,774	11,676	+902 (+8.4%)
⚪	transfer_public_to_public	223,800	223,800		384	384		633,285	633,285		9,661	10,563	+902 (+9.3%)

Contract: token

🚦	Function	Gates			DA Gas			L2 Gas			Proving Time (ms)
		Base	PR	Diff	Base	PR	Diff	Base	PR	Diff	Base	PR	Diff
⚪	burn_private	303,054	303,054		1,024	1,024		713,957	713,957		10,915	11,803	+888 (+8.1%)
⚪	burn_public	223,800	223,800		448	448		672,632	672,632		9,641	10,483	+842 (+8.7%)
⚪	initialize_transfer_commitment	225,054	225,054		768	768		474,500	474,500		9,656	10,423	+767 (+7.9%)
⚪	mint_to_private	355,507	355,507		2,144	2,144		738,070	738,070		11,648	12,688	+1,040 (+8.9%)
⚪	mint_to_public	223,800	223,800		448	448		672,227	672,227		9,639	10,511	+872 (+9.0%)
⚪	transfer_private_to_commitment	259,896	259,896		992	992		511,400	511,400		10,090	10,976	+886 (+8.8%)
⚪	transfer_private_to_private	343,699	343,699		2,592	2,592		557,600	557,600		11,476	12,560	+1,084 (+9.4%)
⚪	transfer_private_to_public	303,110	303,110		1,024	1,024		714,023	714,023		10,803	11,829	+1,026 (+9.5%)
⚪	transfer_private_to_public_with_commitment	307,280	307,280		1,600	1,600		747,323	747,323		10,961	11,889	+928 (+8.5%)
⚪	transfer_public_to_commitment	223,800	223,800		576	576		662,529	662,529		9,696	10,497	+801 (+8.3%)
⚪	transfer_public_to_private	296,520	296,520		992	992		683,304	683,304		10,819	11,833	+1,014 (+9.4%)
⚪	transfer_public_to_public	223,800	223,800		448	448		672,548	672,548		9,621	10,499	+878 (+9.1%)

Contract: vault

🚦	Function	Gates			DA Gas			L2 Gas			Proving Time (ms)
		Base	PR	Diff	Base	PR	Diff	Base	PR	Diff	Base	PR	Diff
⚪	deposit_private_to_private	507,983	507,983		1,312	1,312		878,248	878,248		14,177	15,380	+1,203 (+8.5%)
⚪	deposit_private_to_private_exact	611,708	611,708		1,888	1,888		915,316	915,316		16,094	17,448	+1,354 (+8.4%)
⚪	deposit_private_to_public	435,487	435,487		768	768		862,273	862,273		13,152	14,157	+1,005 (+7.6%)
⚪	deposit_public_to_private	424,931	424,931		1,984	1,984		965,045	965,045		13,015	14,057	+1,042 (+8.0%)
⚪	deposit_public_to_private_exact	424,942	424,942		1,952	1,952		949,469	949,469		12,965	14,048	+1,083 (+8.4%)
⚪	deposit_public_to_public	223,800	223,800		832	832		897,563	897,563		9,783	10,528	+745 (+7.6%)
⚪	issue_private_to_private_exact	611,708	611,708		1,888	1,888		915,976	915,976		16,048	17,411	+1,363 (+8.5%)
⚪	issue_private_to_public_exact	484,222	484,222		1,344	1,344		899,998	899,998		13,959	15,056	+1,097 (+7.9%)
⚪	issue_public_to_private	346,383	346,383		1,376	1,376		921,661	921,661		11,569	12,542	+973 (+8.4%)
⚪	issue_public_to_public	223,800	223,800		832	832		898,253	898,253		9,819	10,509	+690 (+7.0%)
⚪	redeem_private_to_private_exact	614,712	614,712		1,888	1,888		915,823	915,823		16,111	17,444	+1,333 (+8.3%)
⚪	redeem_private_to_public	435,430	435,430		768	768		862,717	862,717		13,154	14,193	+1,039 (+7.9%)
⚪	redeem_public_to_private_exact	428,003	428,003		1,952	1,952		949,790	949,790		13,037	14,099	+1,062 (+8.1%)
⚪	redeem_public_to_public	223,800	223,800		832	832		898,085	898,085		9,707	10,473	+766 (+7.9%)
⚪	withdraw_private_to_private	510,987	510,987		1,312	1,312		878,458	878,458		14,232	15,373	+1,141 (+8.0%)
⚪	withdraw_private_to_private_exact	614,712	614,712		1,888	1,888		915,769	915,769		16,122	17,483	+1,361 (+8.4%)
⚪	withdraw_private_to_public_exact	484,165	484,165		1,344	1,344		900,232	900,232		13,983	15,036	+1,053 (+7.5%)
⚪	withdraw_public_to_private	441,260	441,260		2,528	2,528		967,356	967,356		13,216	14,312	+1,096 (+8.3%)
⚪	withdraw_public_to_public	223,800	223,800		832	832		898,388	898,388		9,743	10,491	+748 (+7.7%)