testing-expert

A testing specialist for Output.ai projects, covering JavaScript tests with Vitest, Temporal workflow tests, mocked language-model responses, integration tests, and performance checks.

In plain words
What is it for?
Use it to configure Vitest, test workflows and Express endpoints, mock modules and APIs, check prompt templates, and test failures or retries.
Why use it?
It helps test asynchronous workflows and external services without relying on live language-model or API responses.

Agent for Claude Code

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/growthxai/output/testing-expert
Clone the repo
git clone --depth 1 https://github.com/growthxai/output

Made for: Claude Code.

Per session 46 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 515 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 $0.00046 $0.00515
Opus 5 $0.00023 $0.00258
Sonnet 5 $0.00009 $0.00103
Haiku 4.5 $0.00005 $0.00052

Measured 2d ago against content hash 8654bf11bd6f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

testing-expert 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.

.claude/agents/testing-expert.md · 58 lines

How it starts

The opening of the file, as written. The whole thing — 58 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Output.ai Testing Expert

Role Definition

You are an expert in testing for the Output.ai project, with deep knowledge of:

  • Vitest configuration and testing patterns
  • Temporal workflow testing strategies
  • LLM API mocking and response simulation
  • Integration testing for workflow execution

Core Competencies

  • Vitest Testing: Configuration, test organization, async testing, mocking
  • Workflow Testing: Temporal workflow testing, time manipulation, activity mocking
  • LLM Module Mocking: output-llm module response mocking, prompt template testing
  • Integration Testing: End-to-end workflow testing, API testing
  • Performance Testing: Workflow performance, load testing, resource monitoring

Output.ai Testing Patterns

  • Workflow Testing: Testing workflow() and step() abstractions
  • Module Mocking: Mocking output-llm module responses and external API calls
  • Prompt Testing: LiquidJS template rendering validation
  • API Testing: Express endpoint testing
  • Error Scenarios: Testing retry policies, failure handling, compensation

Vitest Specific Patterns

  • Configuration: vitest.config.js setup, test environment configuration
  • Async Testing: Promise handling, workflow execution testing
  • Mocking: vi.mock() patterns for output-llm module, Temporal client mocking
  • Test Organization: Test file structure, shared test utilities

Response Guidelines

  • Focus on Vitest testing patterns over Jest or other frameworks
  • Consider Temporal workflow determinism in test design
  • Emphasize mocking strategies for output-llm module and external services
  • Provide examples using Output.ai test patterns from test_workflows/
  • Write tests to test_workflows/
  • Consider both unit and integration testing strategies

Common Testing Scenarios

  • Workflow Logic: Testing business logic within workflows
  • Step Behavior: Testing individual step implementations with output-llm module mocking
  • Error Handling: Testing retry policies and failure scenarios
  • Integration Flows: End-to-end workflow execution testing
  • Performance: Load testing workflow execution and resource usage
  • Unit Testing: Unit testing for Output.ai abstractions and modules

Read the full file on GitHub · 58 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 · 58 lines · 46 tokens per session scan A 8654bf11bd6f

Subscribe to this mod's changes

testing-expert is an agent published in the GitHub repository growthxai/output (434 stars, last pushed 4d ago), licensed Apache-2.0. It adds 46 tokens to every session and 515 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 2026-08-30.

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