test_runner

test_runner is a skill for Claude Code, Codex from jxoesneon/Ciel. It costs 16 tokens per session (336 once invoked), scanned A, original, Apache-2.0.

A testing guide for running tests, checking code coverage, diagnosing failures, and retrying tests with different strategies.

In plain words
What is it for?
Running tests across common programming languages, measuring coverage, examining failure traces, and rerunning only failures, everything, or a selected commit range.
Why use it?
It brings test execution and failure investigation into one workflow instead of leaving you to run commands and inspect results manually.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Running tests across common programming languages, measuring coverage, examining failure traces, and rerunning only failures, everything, or a selected commit range.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/jxoesneon/ciel/test_runner
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add jxoesneon/Ciel --skill test_runner
Clone the repo
git clone --depth 1 https://github.com/jxoesneon/Ciel

Made for: Claude Code, Codex.

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 test_runner

README.md
[![agentmods](https://agentmods.dev/badge/skills/jxoesneon/ciel/test_runner/github.svg)](https://agentmods.dev/skills/jxoesneon/ciel/test_runner)
Your own site
<a href="https://agentmods.dev/skills/jxoesneon/ciel/test_runner"><img src="https://agentmods.dev/badge/skills/jxoesneon/ciel/test_runner/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.

agentmods 80×15 button for test_runner

Your own site · 80×15
<a href="https://agentmods.dev/skills/jxoesneon/ciel/test_runner"><img src="https://agentmods.dev/badge/skills/jxoesneon/ciel/test_runner.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 16 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 336 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.
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 $0.00016 $0.00336
Opus 5.5 $0.00006 $0.00134
Sonnet 5.5 $0.00003 $0.00067
Haiku 4.5 $0.00002 $0.00034

Measured 1mo ago against content hash 50abf0eada20, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

test_runner 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 1mo 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.

ciel.skill/seed_skills/test_runner/SKILL.md · 37 lines

What it actually says

test_runner

Execute and analyze tests.

Operations

  • test.run(target?, filter?) — run tests; returns pass/fail/error counts + failure details.
  • test.coverage(target?) — coverage report with file-level breakdown.
  • test.diagnose(failure) — suggest root cause from stack trace + recent diffs.
  • test.rerun(strategy) — retry-only-failing, full, or bisect-over-commits.

I/O Contract

io_contract:
  input: { op, "target?", "filter?", "coverage?" }
  output: { summary: { passed, failed, skipped }, failures: [ { name, trace } ], "coverage?" }
  idempotent: partial
  side_effects: [shell, fs]

Framework Detection

Auto-detects pytest, jest, mocha, cargo test, go test, rspec, phpunit, dotnet test, JUnit, etc. Respects project test config.

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. 1mo ago First seen · 37 lines · 16 tokens per session scan A 50abf0eada20

Subscribe to this mod's changes

test_runner is a skill published in the GitHub repository jxoesneon/Ciel (1 stars, last pushed 4d ago), licensed Apache-2.0. It adds 16 tokens to every session and 336 once invoked, about $0.0001 per session on Opus 5.5. 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 2026-08-31.

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