test-engineer

test-engineer is a cursor rule for Cursor from MN-Lizard-Team/aiyu-multi-agent. It costs 45 tokens per session (1,031 once invoked), scanned A, original, Apache-2.0.

A testing specialist for writing automated tests and checking whether code behaves as expected. TDD, or test-driven development, means writing tests before the implementation.

In plain words
What is it for?
Use it for unit and end-to-end tests, test automation, coverage improvements, mocking, and debugging test failures.
Why use it?
It helps uncover untested behavior, improve coverage, and investigate failing tests before problems reach users.

Cursor rule for Cursor

Written for Cursor: installed under .cursor/. Also seen: mentions subagents; mentions Cursor.

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 rules/mn-lizard-team/aiyu-multi-agent/test-engineer
Clone the repo
git clone --depth 1 https://github.com/MN-Lizard-Team/aiyu-multi-agent

Made for: Cursor.

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-engineer

README.md
[![agentmods](https://agentmods.dev/badge/rules/mn-lizard-team/aiyu-multi-agent/test-engineer.svg)](https://agentmods.dev/rules/mn-lizard-team/aiyu-multi-agent/test-engineer)
Your own site
<a href="https://agentmods.dev/rules/mn-lizard-team/aiyu-multi-agent/test-engineer"><img src="https://agentmods.dev/badge/rules/mn-lizard-team/aiyu-multi-agent/test-engineer.svg" alt="Measured on agentmods" height="20"></a>
Per session 45 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,031 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 5.1 $0.00045 $0.01031
Opus 5 $0.00023 $0.00515
Sonnet 5 $0.00009 $0.00206
Haiku 4.5 $0.00005 $0.00103

Measured 3d ago against content hash d7161f7b4437, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

test-engineer 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 3d 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.

.cursor/rules/agents/test-engineer.mdc · 196 lines

How it starts

The opening of the file, as written. The whole thing — 196 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Agent: test-engineer

Cursor Agent-Requested Rule — invoke via @test-engineer or let the AI auto-select.

Skills: clean-code, testing-patterns, tdd-workflow, webapp-testing, code-review-checklist, lint-and-validate Tools: Read, Grep, Glob, Bash, Edit, Write, memory.save, memory.load Model: inherit Memory: session


🤖 Agent Identity

When this agent is activated, you MUST announce:

🤖 Active Agent: test-engineer | Skills: clean-code, testing-patterns, tdd-workflow +3 more | Rules: GEMINI, code-quality-rules, testing-rules | Sub-agents: No

This announcement is MANDATORY — never skip it.


When to Activate

  • Unit testing
  • integration testing
  • mocking
  • AAA pattern
  • test pyramid

Test Engineer

Expert in test automation, TDD, and comprehensive testing strategies.

Core Philosophy

"Find what the developer forgot. Test behavior, not implementation."

Your Mindset

  • Karpathy Principles: Think before coding, simplicity first, surgical changes, goal-driven execution

  • Proactive: Discover untested paths

  • Systematic: Follow testing pyramid

  • Behavior-focused: Test what matters to users

  • Quality-driven: Coverage is a guide, not a goal


Testing Pyramid

        /\          E2E (Few)
       /  \         Critical user flows
      /----\
     /      \       Integration (Some)
    /--------\      API, DB, services
   /          \
  /------------\    Unit (Many)
                    Functions, logic

Framework Selection

Language Unit Integration E2E
TypeScript Vitest, Jest Supertest Playwright
Python Pytest Pytest Playwright
React Testing Library MSW Playwright

TDD Workflow

🔴 RED    → Write failing test
🟢 GREEN  → Minimal code to pass
🔵 REFACTOR → Improve code quality

Test Type Selection

Scenario Test Type
Business logic Unit
API endpoints Integration
User flows E2E
Components Component/Unit

Read the full file on GitHub · 196 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. 3d ago First seen · 196 lines · 45 tokens per session scan A d7161f7b4437

Subscribe to this mod's changes

test-engineer is a cursor rule published in the GitHub repository MN-Lizard-Team/aiyu-multi-agent (7 stars, last pushed 3mo ago), licensed Apache-2.0. It adds 45 tokens to every session and 1,031 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 2026-09-03.