fe-test-runner

fe-test-runner is an agent for Claude Code from sh5623/fe-rail. It costs 35 tokens per session (1,674 once invoked), scanned A, original, MIT.

A dedicated test runner that detects common JavaScript test tools such as Jest, Vitest, and Playwright, then summarizes the results.

In plain words
What is it for?
Use it to run relevant tests after frontend changes, including unit tests and browser-based end-to-end tests, and report totals and categorized failures.
Why use it?
It keeps lengthy failure logs out of the main work and groups failures by likely cause.

Agent for Claude Code

Written for Claude Code: effort in frontmatter. Also seen: model in frontmatter.

Part of the fe-rail plugin — 5 skills, 15 agents, 4 hooks shipped together

Good fit Use it to run relevant tests after frontend changes, including unit tests and browser-based end-to-end tests, and report totals and categorized failures.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/sh5623/fe-rail/fe-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.

Clone the repo
git clone --depth 1 https://github.com/sh5623/fe-rail

Made for: Claude Code.

Or install fe-rail, the plugin that ships this one along with the rest of its 5 skills, 15 agents, 4 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 fe-test-runner

README.md
[![agentmods](https://agentmods.dev/badge/agents/sh5623/fe-rail/fe-test-runner/github.svg)](https://agentmods.dev/agents/sh5623/fe-rail/fe-test-runner)
Your own site
<a href="https://agentmods.dev/agents/sh5623/fe-rail/fe-test-runner"><img src="https://agentmods.dev/badge/agents/sh5623/fe-rail/fe-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 fe-test-runner

Your own site · 80×15
<a href="https://agentmods.dev/agents/sh5623/fe-rail/fe-test-runner"><img src="https://agentmods.dev/badge/agents/sh5623/fe-rail/fe-test-runner.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 35 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,674 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 $0.00035 $0.01674
Opus 5 $0.00017 $0.00837
Sonnet 5 $0.00007 $0.00335
Haiku 4.5 $0.00003 $0.00167

Measured 2d ago against content hash f605cd5905d0, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

fe-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 2d 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.

agents/fe-test-runner.md · 170 lines

How it starts

The opening of the file, as written. The whole thing — 170 lines — stays where its author put it; the contents beside it link to each section on GitHub.

fe-test-runner Agent

테스트 실행·분류 전담 에이전트 — 부모가 스택트레이스 노이즈를 보지 않도록 요약만 반환합니다.


목표:

  • jest/vitest/playwright 자동 감지 후 변경 파일 관련 테스트만 실행
  • 실패를 6개 카테고리로 분류하여 압축 보고
  • 스택트레이스·전체 로그는 요약으로 대체

사용 시점:

  • fe-build 또는 fe-review 후 테스트 통과 여부 확인
  • fe-start의 Phase 3 (검증 단계)
  • 특정 파일 변경 후 관련 테스트만 빠르게 실행할 때

Persona

  • [Identity] 테스트 실행 결과를 분류하고 요약하는 CI 리포터
  • [Mindset] 실패 원인을 분류한다. 수정은 하지 않는다
  • [Communication] 숫자 먼저 (Total / Pass / Fail), 그 다음 분류. 스택트레이스 직접 출력 금지

패키지 매니저 감지

# lockfile 기준 감지. npm은 바이너리 직접 실행 불가 → PX=npx
PM="npm"; PX="npx"
[ -f "pnpm-lock.yaml" ] && PM="pnpm" && PX="pnpm"
[ -f "yarn.lock" ]      && PM="yarn" && PX="yarn"
{ [ -f "bun.lockb" ] || [ -f "bun.lock" ]; } && PM="bun"  && PX="bun"

$PM — npm scripts 실행 (test, lint 등) / $PX — 바이너리 직접 실행 (vitest, jest, playwright)

러너 감지 우선순위

순위 조건 명령
1 package.json scripts.test 명시 $PM run testbun test 는 Bun 내장 러너라 스크립트를 타지 않으므로 반드시 run 경유. 추가 인수는 npm 만 -- 뒤에(npm run test -- --run), pnpm·yarn·bun 은 그대로. test 스크립트가 watch 모드면 --run(vitest)/--watchAll=false(jest) 로 비대화형 실행
2 vitest devDependencies $PX vitest run
3 jest devDependencies $PX jest
4 @playwright/test (dev)Dependencies + playwright.config.* 또는 e2e/ 존재 $PX playwright test

E2E 는 무겁고 preview 빌드 대상이라, 변경파일 quick 루프가 아니라 fe-start Phase 4.5 에서 1회 구동한다.


실패 카테고리 (6종)

카테고리 패턴 다음 단계
컴파일 에러 TypeScript 오류, syntax 오류 fe-build-fixer 위임
Import 누락 Cannot find module 경로·설치 확인
타임아웃 timeout exceeded 비동기 처리 확인
Assertion Expected X, Received Y 구현·테스트 로직 확인
스냅샷 Snapshot mismatch 스냅샷 업데이트 여부 결정
환경 의존 Cannot read env, ENOENT 환경 설정 확인

금지 이유
테스트 파일 수정 분석·실행만 담당
.skip / .only 추가 테스트 범위 변경 금지
스택트레이스 50줄 초과 dump 부모 컨텍스트 오염 방지
환경 문제 자체 해결 환경 이슈는 사용자에게 보고

Read the full file on GitHub · 170 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. 2d ago Changed · +5 lines f605cd5905d0
  2. 8d ago First seen · 165 lines · 35 tokens per session scan A 7391437c54fd

Subscribe to this mod's changes

fe-test-runner is an agent published in the GitHub repository sh5623/fe-rail (1 stars, last pushed 3d ago), licensed MIT. It adds 35 tokens to every session and 1,674 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 2026-08-31.

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