sveltejs/svelte142 installs

performance-investigation

Q: How do I install this agent skill?

Run npx skills add https://github.com/sveltejs/svelte --skill performance-investigation.

Q: Is this agent skill safe to install?

Review the displayed partner audits, complete source, permissions, dependencies, and exact revision before installing.

Investigate performance regressions and find opportunities for optimization

How do I install this agent skill?

npx skills add https://github.com/sveltejs/svelte --skill performance-investigation

view source ↗

Is this agent skill safe to install?

Gen Agent Trust Hubpass
The skill provides instructions for performance benchmarking and optimization. It utilizes standard local development commands and processes locally generated reports. No security risks were identified.
Socketpass
No alerts
Snykpass
Risk: LOW · No issues

What does this agent skill do?

Quick start

Start from a branch you want to measure (for example foo).
Run:

pnpm bench:compare main foo

If you pass one branch, bench:compare automatically compares it to main.

Where outputs go

Summary report: benchmarking/compare/.results/report.txt
Raw benchmark numbers:
- benchmarking/compare/.results/main.json
- benchmarking/compare/.results/<your-branch>.json
CPU profiles (per benchmark, per branch):
- benchmarking/compare/.profiles/main/*.cpuprofile
- benchmarking/compare/.profiles/main/*.md
- benchmarking/compare/.profiles/<your-branch>/*.cpuprofile
- benchmarking/compare/.profiles/<your-branch>/*.md

The .md files are generated summaries of the CPU profile and are usually the fastest way to inspect hotspots.

Suggested investigation flow

Open benchmarking/compare/.results/report.txt and identify largest regressions first.
For each high-delta benchmark, compare:
- benchmarking/compare/.profiles/main/<benchmark>.md
- benchmarking/compare/.profiles/<branch>/<benchmark>.md
Look for changes in self/inclusive hotspot share in runtime internals (runtime.js, reactivity/batch.js, reactivity/deriveds.js, reactivity/sources.js).
Make one optimization change at a time, then re-run targeted benches before re-running full compare.

Fast benchmark loops

Run only selected reactivity benchmarks by substring:

pnpm bench kairo_mux kairo_deep kairo_broad kairo_triangle
pnpm bench repeated_deps sbench_create_signals mol_owned

Tests to run after perf changes

Runtime reactivity regressions are most likely in runes runtime tests:

pnpm test runtime-runes

Helpful script

For quick cpuprofile hotspot deltas between two branches:

node benchmarking/compare/profile-diff.mjs kairo_mux_owned main foo

This prints top function sample-share deltas for the selected benchmark.

Practical gotchas

bench:compare checks out branches while running. Avoid uncommitted changes (or stash them) so branch switching is safe.
Each bench:compare run rewrites benchmarking/compare/.results and benchmarking/compare/.profiles.

How can the creator link this skill?

Add the canonical catalog link to the repository README so users can inspect current installs and available audits. The publishing guide covers the complete discovery path.

<a href="https://skillzs.dev/skills/sveltejs/svelte/performance-investigation">View performance-investigation on skillZs</a>