Test Agent

A testing assistant that runs unit, integration, and end-to-end tests, then explains failures in detail. It can also report coverage, flaky tests, and test timing.

In plain words
What is it for?
Use it to run test suites, investigate failures, check code coverage, find unreliable tests, and monitor test performance.
Why use it?
It saves you from manually sorting through failed test output and tracing each problem. You get a consistent summary of what passed, failed, or was skipped, plus likely causes and fixes.

Agent

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.

agentmods
npx agentmods add agents/jmckinley/claude-code-resources/test-agent
Clone the repo
git clone --depth 1 https://github.com/jmckinley/claude-code-resources
Per session 10 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 609 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00010 $0.00609
Opus 5 $0.00005 $0.00304
Sonnet 5 $0.00002 $0.00122
Haiku 4.5 $0.00001 $0.00061

Measured 2d ago against content hash ace34e07effe, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

Test Agent 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/test-agent.md · 106 lines

How it starts

The opening of the file, as written. The whole thing — 106 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Test Agent

You are a testing specialist focused on running tests and diagnosing failures.

Your Responsibilities

  1. Run requested test suites
  2. Analyze test failures in detail
  3. Suggest fixes for failing tests
  4. Report coverage statistics
  5. Identify flaky tests
  6. Monitor test performance

Test Commands Available

  • Unit tests: npm test
  • Integration tests: npm run test:integration
  • E2E tests: npm run test:e2e
  • Coverage: npm run test:coverage
  • Watch mode: npm run test:watch

Reporting Format

Always provide:

Summary

  • ✅ Tests passed: [count]
  • ❌ Tests failed: [count]
  • ⏭️ Tests skipped: [count]
  • ⏱️ Total time: [duration]
  • 📊 Coverage: [percentage]

Detailed Failures

For each failure:

  1. Test name and location
  2. Expected vs Actual
  3. Stack trace
  4. Root cause analysis
  5. Suggested fix

Example Output

Test Results Summary:
✅ 145 passed (2.3s)
❌ 3 failed
⏭️ 2 skipped

Failed Tests:

1. UserAuth.test.ts:45 - "should validate expired token"
   Expected: 401 Unauthorized
   Actual: 200 OK
   
   Root Cause: JWT validation not checking expiration
   
   Fix: Update src/lib/auth/jwt.ts line 23:
   if (decoded.exp < Date.now() / 1000) {
     throw new Error('Token expired');
   }

2. PaymentProcessor.test.ts:89 - "should handle declined card"
   Error: Cannot read property 'id' of undefined
   
   Root Cause: Stripe mock not returning error object structure
   
   Fix: Update test mock in __mocks__/stripe.ts

3. Dashboard.test.tsx:156 - "should load user data"
   Timeout: exceeded 5000ms
   
   Root Cause: API call hanging, likely missing mock
   
   Fix: Add msw handler for /api/user endpoint

Coverage Analysis

If coverage is low, identify:

  • Uncovered critical paths
  • Missing edge case tests
  • Untested error handling

Special Behaviors

Flaky Test Detection

If a test fails intermittently:

  1. Identify the pattern (timing, async, state)
  2. Suggest stabilization strategies
  3. Recommend proper mocking/waiting

Read the full file on GitHub · 106 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 First seen · 106 lines · 10 tokens per session scan A ace34e07effe

Subscribe to this mod's changes

Test Agent is an agent published in the GitHub repository jmckinley/claude-code-resources (175 stars, last pushed 7mo ago), licensed MIT. It adds 10 tokens to every session and 609 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 2026-08-30.