bun: Skill for Claude Code

.claude/skills/writing-bundler-tests/SKILL.md

writing-bundler-tests is a skill for Claude Code from oven-sh/bun. It costs 42 tokens per session (1,238 once invoked), scanned A, original, no licence file.

A guide for writing tests for a bundler, transpiler, or other code transformation using the project's itBundled and expectBundled helpers.

In plain words
What is it for?
Use it when creating or changing tests that check how code is bundled, transpiled, or transformed.
Why use it?
It helps keep these tests consistent and puts them in the expected test/bundler/ location.

Skill for Claude Code

Written for Claude Code: installed under .claude/.

This is oven-sh/bun's own configuration. It tells Claude Code how to work on bun itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything bun configures →

Reuse

Borrowing it

Nothing to install: this file belongs to oven-sh/bun. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/oven-sh/bun/main/.claude/skills/writing-bundler-tests/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/oven-sh/bun

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for writing-bundler-tests

README.md
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Your own site
<a href="https://agentmods.dev/skills/oven-sh/bun/writing-bundler-tests"><img src="https://agentmods.dev/badge/skills/oven-sh/bun/writing-bundler-tests/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

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Your own site · 80×15
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Per session 42 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,238 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin unknown No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00042 $0.01238
Opus 5 $0.00021 $0.00619
Sonnet 5 $0.00008 $0.00248
Haiku 4.5 $0.00004 $0.00124

Measured 13d ago against content hash 5e9ef4c764da, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

writing-bundler-tests scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 13d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/skills/writing-bundler-tests/SKILL.md · 223 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 13d ago First seen · 223 lines · 42 tokens per session scan A 5e9ef4c764da

Subscribe to this mod's changes

writing-bundler-tests is a skill published in the GitHub repository oven-sh/bun (95,945 stars, last pushed today), with no licence file. It adds 42 tokens to every session and 1,238 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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