bun-test-coverage

bun-test-coverage is a skill for Claude Code from secondsky/claude-skills. It costs 26 tokens per session (865 once invoked), scanned A, original, MIT.

A guide to measuring which parts of a codebase are exercised by Bun tests. Code coverage reports show tested functions and lines, including lines that tests miss.

In plain words
What is it for?
Use it to produce console or LCOV reports, set coverage thresholds, exclude test files, and include coverage in continuous integration.
Why use it?
It makes gaps in the test suite visible and can set a minimum coverage level for automated checks.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Needs its repository: it runs a file that does not travel with it, so clone the repository first. The line is files: ./coverage/lcov.info.

Part of the bun plugin — 27 skills, 6 commands, 3 agents, 2 hooks shipped together

not rated 215repo +2 today A scan Socket: passSnyk: passSkillSpector: pass 26 tokens original MIT

Good fit Use it to produce console or LCOV reports, set coverage thresholds, exclude test files, and include coverage in continuous integration.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/secondsky/claude-skills
agentmods
npx agentmods add skills/secondsky/claude-skills/bun-test-coverage

Made for: Claude Code.

Or install bun, the plugin that ships this one along with the rest of its 27 skills, 6 commands, 3 agents, 2 hooks.

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 bun-test-coverage

README.md
[![agentmods](https://agentmods.dev/badge/skills/secondsky/claude-skills/bun-test-coverage.svg)](https://agentmods.dev/skills/secondsky/claude-skills/bun-test-coverage)
Your own site
<a href="https://agentmods.dev/skills/secondsky/claude-skills/bun-test-coverage"><img src="https://agentmods.dev/badge/skills/secondsky/claude-skills/bun-test-coverage.svg" alt="Measured on agentmods" height="20"></a>
Per session 26 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 865 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
  • Socket pass 4 Apr 2026
  • Snyk pass 4 Apr 2026
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original 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 $0.00026 $0.00865
Opus 5 $0.00013 $0.00432
Sonnet 5 $0.00005 $0.00173
Haiku 4.5 $0.00003 $0.00086

Measured 4d ago against content hash df5f39e73236, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

bun-test-coverage 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 4d 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.

plugins/bun/skills/bun-test-coverage/SKILL.md · 163 lines

How it starts

The opening of the file, as written. The whole thing — 163 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Bun Test Coverage

Bun has built-in code coverage reporting without additional dependencies.

Enabling Coverage

# Enable coverage
bun test --coverage

# With threshold (fail if below)
bun test --coverage --coverage-threshold 80

Configuration in bunfig.toml

[test]
coverage = true
coverageThreshold = 0.8  # 80% minimum
coverageDir = "./coverage"

# Patterns to ignore
coverageSkipTestFiles = true

Coverage Output

------------------|---------|---------|-------------------
File              | % Funcs | % Lines | Uncovered Line #s
------------------|---------|---------|-------------------
All files         |   85.71 |   89.23 |
 src/index.ts     |  100.00 |  100.00 |
 src/utils.ts     |   75.00 |   82.35 | 23-25, 41-43
 src/api.ts       |   80.00 |   85.00 | 67, 89-92
------------------|---------|---------|-------------------

Coverage Reporters

# Default console output
bun test --coverage

# Generate lcov report
bun test --coverage --coverage-reporter=lcov

# Multiple reporters
bun test --coverage --coverage-reporter=text --coverage-reporter=lcov

Available Reporters

Reporter Output
text Console table (default)
lcov coverage/lcov.info for CI tools
json coverage/coverage.json

Coverage Thresholds

Set minimum coverage requirements:

# Fail if coverage < 80%
bun test --coverage --coverage-threshold 80

# Per-metric thresholds in bunfig.toml
[test]
coverage = true
coverageThreshold = {
  lines = 80,
  functions = 75,
  branches = 70
}

Excluding Files

[test]
coverage = true

# Skip test files from coverage
coverageSkipTestFiles = true

# Patterns to exclude
coverageIgnore = [
  "**/*.test.ts",
  "**/fixtures/**",
  "**/mocks/**"
]

CI Integration

GitHub Actions

- name: Run tests with coverage
  run: bun test --coverage --coverage-reporter=lcov

- name: Upload coverage to Codecov
  uses: codecov/codecov-action@v5
  with:
    files: ./coverage/lcov.info

Read the full file on GitHub · 163 lines

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. 4d ago First seen · 163 lines · 26 tokens per session scan A df5f39e73236

Subscribe to this mod's changes

bun-test-coverage is a skill published in the GitHub repository secondsky/claude-skills (215 stars, last pushed today), licensed MIT. It adds 26 tokens to every session and 865 once invoked, about $0.0001 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 2026-09-03.